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  • 1.
    Aggemyr, Elsa
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Cousins, Sara A. O.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Landscape structure and land use history influence changes in island plant composition after 100 years2012In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 39, no 9, p. 1645-1656Article in journal (Refereed)
    Abstract [en]

    Aim We investigated how current and historical land use and landscape structure affect species richness and the processes of extinction, immigration and species turnover. Location The northern part of the Stockholm archipelago, Baltic Sea, Sweden. We resurveyed 27 islands ranging from 0.3 to 33 ha in area. Methods We compared current plant survey data, cadastral maps and aerial photographs with records obtained from a survey in 1908, using databases and a digital elevation model to examine changes in plant community dynamics in space and time. We examined the effects of local and landscape structure and land use changes on plant species dynamics by using stepwise regression in relation to eight local and three landscape variables. The eight local variables were area, relative age, shape, soil heterogeneity, bedrock ratio, number of houses, forest cover change, and grazing 100 years ago. The three landscape variables were distance to mainland, distance to closest island with a farm 100 years ago, and structural connectivity. Hanskis connectivity measure was modified to incorporate both connectivity and fragmentation. Results The investigated islands have undergone drastic changes, with increasing forest cover, habitation, and abandonment of grassland management. Although the total species richness increased by 31% and mean island area by 23%, we found no significant increase in species richness per unit area. Local variables explain past species richness (100 years ago), whereas both local and landscape variables explain current species richness, extinctions, immigrations and species turnover. Grazing that occurred 100 years ago still influences species richness, even though grazing management was abandoned several decades ago. The evidence clearly shows an increase in nitrophilous plant species, particularly among immigrant species. Main conclusions This study highlights the importance of including land use history when interpreting current patterns of species richness. Furthermore, local environment and landscape patterns affect important ecological processes such as immigration, extinction and species turnover, and hence should be included when assessing the impact of habitat fragmentation and land use change. We suggest that our modified structural connectivity measure can be applied to other types of landscapes to investigate the effects of fragmentation and habitat loss.

  • 2.
    Aggemyr, Elsa
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Cousins, Sara A. O.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Plant species richness and composition, changes over a 100 year period in the Swedish archipelago - a landscape study2010In: The Future of Biodiversity: Genes, Species, Ecosystems: 40th Anniversary Conference / [ed] Volkmar Wolters, Janine Groh, Franziska Peter, Rainer Waldhardt, Giessen: Justus Liebig University Giessen , 2010, p. 118-118Conference paper (Refereed)
  • 3. Ahlkrona, Josefin
    et al.
    Lötstedt, Per
    Kirchner, Nina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zwinger, Thomas
    Dynamically coupling the non-linear Stokes equations with the shallow ice approximation in glaciology: Description and first applications of the ISCAL method2016In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 308, p. 1-19Article in journal (Refereed)
    Abstract [en]

    We propose and implement a new method, called the Ice Sheet Coupled Approximation Levels (ISCAL) method, for simulation of ice sheet flow in large domains during long time-intervals. The method couples the full Stokes (FS) equations with the Shallow Ice Approximation (SIA). The part of the domain where SIA is applied is determined automatically and dynamically based on estimates of the modeling error. For a three dimensional model problem, ISCAL computes the solution substantially faster with a low reduction in accuracy compared to a monolithic FS. Furthermore, ISCAL is shown to be able to detect rapid dynamic changes in the flow. Three different error estimations are applied and compared. Finally, ISCAL is applied to the Greenland Ice Sheet on a quasi-uniform grid, proving ISCAL to be a potential valuable tool for the ice sheet modeling community.

  • 4.
    Alavimoghaddam, Mohammadreza
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Assessing the ability of HEC-HMS rainfall-runoff model to simulate stream flow across Sweden2017Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Computer modeling is the powerful tool for simulating nature’s behavior; however, still more efforts are need for reaching perfect simulation with computer models (especially in the hydrological field of study). In this Master’s thesis, the accuracy of the HEC-HMS computer model for long term rainfall-runoff simulation was evaluated across Sweden. Five different catchments from north to south of Sweden were selected and then simulation have done for 34 years of available data. Simulation was conducted using daily, monthly and yearly time scale resolutions. Results from the north to the south of Sweden were completely different. Simulated runoff and observed runoff in northern catchments followed the same pattern over different time scales but in the southern part of Sweden the results had different patterns in space and time. The best results with HEC-HMS were found in the northern catchments with steep main river slopes. In the southern catchments the model could not predict runoff in any realistic manner at any time and space scale. In total the HEC-HMS model cannot simulate the rainfall runoff for long periods of simulation across Sweden. This is especially true in southern parts of the country dominate with low elevation catchments. However, with regards to its ability for event-based simulation HEC-HMS could be a suitable tool to simulate flood event discharges that are needed for road or other hydraulic structures designs. But, this would require significant amounts of calibration and model development.

  • 5. Alekseeva, I.
    et al.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Schrum, C.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Reconstruction of historic changes of the Aral Sea water budget and sea-groundwater interactions by a coupled 3D sea-ice-groundwater model2007In: Geophysical Research Abstracts, Vol. 9, 10629, 2007, 2007Conference paper (Other academic)
    Abstract [en]

    A 3D coupled sea-ice-groundwater model has been developed and applied for an estimation of the water balance and groundwater-seawater interactions in the shrinking Aral Sea. The model developed combines the complete 3D sea-ice hydrodynamics model ECOSMO, including a mass and energy conserving wetting and drying scheme, and a simple groundwater model based on changes in hydraulic gradient in response to the sea surface variability. During the simulation period 1979-1993, the model successfully reproduced the rapid Aral Sea level drop, surface area decrease, coastline position changes and salinization. Model predictions of evaporation and groundwater inflow were also consistent with independent estimations. Model results indicated that within the 15 years period of simulations the net groundwater inflow to the Aral Sea might have increased by 10% or more as a direct effect of the sea level lowering.

    Furthermore, model scenario tests were carried out to examine effects of salinity on sea hydrodynamics and to estimate non-linear feedbacks of the sea thermo- and hydrodynamics, air-sea turbulent fluxes and the sea water balance. It was shown that a neglect of salinity in the sea hydro- and thermo dynamics resulted in considerable differences in the Aral Sea winter thermal conditions, which in turn influenced the air-sea exchange in the following spring and summer. As a result, the zero salinity scenario predicted higher evaporation rates and an considerably accelerated sea level lowering by up to 2 cm/yr, in comparison with the basic model run. An indirect influence of the fresh groundwater inflow in terms of water balance has been identified as less significant, however it was shown that the fresh groundwater input could influence the Aral Sea salinity distribution considerably since 1990’s.

  • 6.
    Ampel, Linda
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Kylander, Malin E.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Steinthorsdottir, Margret
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Wohlfarth, Barbara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Abrupt climate change and early lake development - the Lateglacial diatom flora at Hasseldala Port, southeastern Sweden2015In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 44, no 1, p. 94-102Article in journal (Refereed)
    Abstract [en]

    The fossil diatom record from the Hasseldala Port palaeolake, southeastern Sweden, offers an excellent opportunity to investigate how past climatic shifts influenced catchment conditions and early lake development. The record, dating to between 13900 and 11200 cal. a BP, covers a climatically dynamic period, starting with deglaciation followed by oscillations between warmer and colder climate states. The stratigraphical changes in the fossil diatom assemblages show a trend of less open-water taxa and a successively more complex periphytic community as the lake shallows and the aquatic habitat structure develops. A diatom-based reconstruction of lake water pH indicates a natural acidification trend early in the record from 13900 to 12500 cal. a BP. From 12500 cal. a BP, coincident with the start of climate cooling, to 11300 cal. a BP this trend is disrupted and lake waters become more alkaline. A cooler and drier climate most likely resulted in reduced soil organic matter build-up as well as more frozen ground that impeded hydrological flow and decreased the input of dissolved organic matter and organic acids into the lake system. This study demonstrates the importance of the hydrological system as a link between terrestrial and aquatic ecosystems during early lake ontogeny.

  • 7.
    Andersson, Ingela
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Implementing the European Water Framework Directive at local to regional level -Case Study Northern Baltic Sea River Basin District, Sweden2011Licentiate thesis, comprehensive summary (Other academic)
  • 8.
    Andersson, Ingela
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Petersson, Mona
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Impact of the European Water Framework Directive on local-level water management: Case study Oxunda Catchment, Sweden2012In: Land use policy, ISSN 0264-8377, E-ISSN 1873-5754, Vol. 29, no 1, p. 73-82Article in journal (Refereed)
    Abstract [en]

    The Water Framework Directive (WFD) of the European Union provides a common framework for waterpolicy that focuses on holistic and integrated water management in river basins. In many member states,implementation of the WFD has shifted the main responsibility for local water issues from the municipallevel to the regional or supra-regional levels. In this study, we investigated how the implementation of theWFD has influenced local-level water management including the interpretation of the new environmentalquality standards. Specifically, we considered Sweden, which has traditionally had relatively stronggovernance at the municipal level. Because a sufficient amount of time has now passed for evaluationof WFD-related effects on operational water handling, we interviewed individuals directly involved inwater planning and land use planning at the municipal level in one sub catchment in the Northern BalticSea River Basin District of Sweden, as well as representatives for superior levels and associations. Despitedivergent views regarding the priority of water issues in physical planning among the local-level plannersinterviewed, they had all participated in successful inter-municipal pre-WFD collaboration projects.Although such collaborations could help increase the understanding and acceptance of WFD-related goalsand costs, as well as facilitate conflict solving, as shown in the Oxunda Catchment, they have not gainedmuch attention in the WFD implementation process. Additionally, physical planners have generally beenreluctant to accept new environmental quality standards resulting from WFD implementation, in partbecause they lack precise definitions, but also because they could challenge the municipal routine ofweighing various objectives against each other. Furthermore, despite WFD-related increases in ambitionlevels, lack of resource improvements at the municipal level were identified as potential problems by local environmental planners.

  • 9.
    Andréen, Sigrid
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The development of landscape structures affecting biodiversity in the Hanveden and Tyresta green wedges2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The green wedges of Stockholm are meant to support a high level of biodiversity as well as cultural and recreational services but evaluating the spatial development of the wedges is difficult because their delineation has changed since they were first used in a regional development plan. This study examines a part of the Hanveden and Tyresta wedges in southern Stockholm, with the goal to use robust ecological theory to evaluate the development of the wedges from 1992 until today with focus on conserving a high level of biodiversity. Using an already existing GIS-based method of identifying connectivity weaknesses in the wedges, more weaknesses were found in 2010 than in 1992 although the total area of the wedges had only declined 3.3%. The shape of the wedges had also changed, with more narrow parts in 2010 than in 1992. To more effectively compare the development of factors in the landscape that are relevant for biodiversity, this study proposes a new method using the common shrew and hazel grouse as surrogate species. The total area loss for the common shrew was 2.96% from 1991 to 2013 and 2.23% for the hazel grouse. Fragmentation increased for both species. A large part of the greenspaces relevant to the surrogate species are covered by the green wedges, meaning that important cultural and recreational values identified by the county council are also present in areas relevant to the surrogate species. Using surrogate species to delineate and monitor the green wedges could enhance the cultural and recreational qualities of the wedges, emphasize the need for connectivity planning, identify ecologically important parts of the greenspaces as well as provide a tool for following up the development of the urban greenspaces of Stockholm. However, formulating goals relevant to biodiversity is important to fully evaluate development and municipal cooperation is needed.

  • 10.
    Andwinge, Maria
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Reading Pollen Records at Peloponnese, Greece2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The eastern Mediterranean area is a region of high archaeological importance, it is also a region where climate has been a force interacting with humans in shaping the landscape and vegetation history. Variations in pollen content and composition in various climate archives (e.g. lake sediments and peat sections) are widely used to reconstruct vegetation changes and human impact in the Quaternary environments. Pollen sampling has been conducted throughout the Peloponnese peninsula but there is a lack of regional synthesis of these locally based studies. The aims of the thesis are partly to show how pollen data may be used in a regional analysis on Late Pleistocene and Holocene vegetation changes, partly to assemble all published pollen data from Peloponnese peninsula in a database. The question formulations are; i) how may a database with pollen dataserve as a basis for interpretations of regional vegetation changes on Peloponnese?, ii) what are the possibilities of using classification of pollen and distinguish between driving factors behind the historic vegetation changes? The constructed database facilitates further research regarding pollen records at Peloponnese. Pollen recordsmay show important patterns in landscape changes during Late Pleistocene and Holocene but using pollen records at a regional scale need comparisons between coring sites which may be troublesome due to different approaches, different species investigated and varied calculation of pollen sum. In order to distinguish between driving forces and actors affecting the vegetation, pollen data may be used both in detail but also in using groups and classifications of the pollen included.

  • 11.
    Antikainen, Catarina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Formation and Retention of Soil Organic Matter (SOM) in the Taygetos Mountains (Greece): Influence of Soil Properties and Wildfire2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Deforestation and soil degradation is a worldwide problem, and especially so in the Greek Taygetos mountains. With wildfires affecting thousands of square kilometers of land, soil quality assessments are important in order to choose the right land management measures in the process of landscape restoration. Soil organic matter (SOM) is a good indicator of soil quality, but its response to wildfires and dependence on other soil properties is not well known in the Taygetos area. This study attempts to investigate the influence of topographic aspect and slope inclination on SOM formation and retention in fire damaged forests. Results are put into context with other soil properties such as pH and water content as well as the influence of wildfires. The study found unexpectedly high amounts of SOM in all sampled slopes, which was attributed to the incorporation of charcoal from burnt litter produced during low intense fires. No correlation was detected between SOM and aspect, and only a weak negative correlation between SOM and slope inclination. However, the study found a strong correlation between SOM amounts and water content, which suggests that water is one of the main limiting factors of SOM in the Taygetos mountains.

  • 12.
    Applegate, Patrick J.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Kirchner, Nina
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Stone, E. J.
    Keller, K.
    Greve, R.
    An assessment of key model parametric uncertainties in projections of Greenland ice sheet behavior2012In: The Cryosphere, ISSN 1994-0416, E-ISSN 1994-0424, Vol. 6, no 3, p. 589-606Article in journal (Refereed)
    Abstract [en]

    Lack of knowledge about the values of ice sheet model input parameters introduces substantial uncertainty into projections of Greenland Ice Sheet contributions to future sea level rise. Computer models of ice sheet behavior provide one of several means of estimating future sea level rise due to mass loss from ice sheets. Such models have many input parameters whose values are not well known. Recent studies have investigated the effects of these parameters on model output, but the range of potential future sea level increases due to model parametric uncertainty has not been characterized. Here, we demonstrate that this range is large, using a 100-member perturbed-physics ensemble with the SICOPOLIS ice sheet model. Each model run is spun up over 125 000 yr using geological forcings and subsequently driven into the future using an asymptotically increasing air temperature anomaly curve. All modeled ice sheets lose mass after 2005 AD. Parameters controlling surface melt dominate the model response to temperature change. After culling the ensemble to include only members that give reasonable ice volumes in 2005 AD, the range of projected sea level rise values in 2100 AD is similar to 40 % or more of the median. Data on past ice sheet behavior can help reduce this uncertainty, but none of our ensemble members produces a reasonable ice volume change during the mid-Holocene, relative to the present. This problem suggests that the model's exponential relation between temperature and precipitation does not hold during the Holocene, or that the central-Greenland temperature forcing curve used to drive the model is not representative of conditions around the ice margin at this time (among other possibilities). Our simulations also lack certain observed physical processes that may tend to enhance the real ice sheet's response. Regardless, this work has implications for other studies that use ice sheet models to project or hindcast the behavior of the Greenland Ice Sheet.

  • 13.
    Aringo, Deborah
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Climate-resilient cities: A comparative study of climate adaptationstrategies in Botkyrka and Ekerö municipalities2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis research investigates and contributes to increased knowledge on municipalities’ approaches to climate adaptation and associated challenges that slow down or hinder climate adaptation approaches in cities. The Stockholm region has experienced climate change and impacts of severe floods, heat waves, storms, sea level rise, forest-fire outbreaks, erosion and landslides. To control the frequency and magnitude of these impacts, local authorities and administrations need to integrate mitigation and adaptation management strategies into physical plans of towns and cities.

    Surveys carried out in 2016 and 2017 consecutively, evaluate municipalities’ efforts in climate adaptation in different counties in Sweden. The survey report in 2017 reveals that not all municipalities are equally implementing climate adaptation in Stockholm county; and yet the impacts of climate change are to affect all municipalities regardless of size and geographical location.

    Therefore, to understand the state of climate change adaptation in the municipalities, the author interviewed municipal planners, engineers, environmental investigators, and climate group in Botkyrka, to collect qualitative data for analysis. Data was also gathered through qualitative document analysis to compare drivers of municipality approaches to climate adaptation in Botkyrka and Ekerö municipality. The study results show that there is a gap between Botkyrka and Ekerö municipalities’ climate adaptation work. However, much as these two municipalities are sustainably eveloping, they face a number of challenges that hamper their ability to integrate climate adaptation measure in urban physical plans in order to reduce urban vulnerabilities, and thus build sustainable and climate-resilient cities.

  • 14.
    Arleskär, Staffan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Bostadsrätt, gräsmark eller skog?: Hur har exploatering för bostadsbyggande år 2000-2015 påverkat Järvakilens funktion som spridningsväg?2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Urbanization is a key driver of habitat loss, ecosystem degradation and has a great impact on biodiversity. Exploitation of buffer zones surrounding conservation areas and green structures in urban environment can affect biodiversity through reduced total area of habitat, increased edge effects and lost connectivity on a landscape level. The previous regional development plans for the Stockholm region, had the purpose of leaving large green structures undeveloped to secure core areas of great biological value by focusing on a dense city core. However, the latest regional development strategy puts stress on the green wedges by shifting the focal areas of the development into suburban regional city centers, in many cases close to the green wedges. The purpose of this study was to map habitat loss and changes in the total area of the Järva green wedge, west of Stockholm, caused by development of housing areas in previously sparsley exploited buffer zones, during the period 2000 – 2015. The study uses theories of landscape ecology, remote sensing and GIS to map and quantify habitat loss between 2000 and 2015. Two different birds were used as surrogate species, one grassland habitat specialist – Corncrake (Crex crex) and one forest habitat generalist – Eurasian jay (Garrulus glandarius). The two different surrogate species were used to identify how loss of two nature types could influence biodiversity and connectivity for a group of species. Documents and development plans on regional and local scale were also used to map and predict further habitat loss and exploitation of the green wedge until 2030. The result of the study shows that grassland habitat lost nearly twice the area than forest habitat due to development of housing areas during the period 2000 to 2015. A total of 1.3 km² of grassland and 0.7 km² forest habitat were replaced by housing areas during the fifteen years covered in the study, and the Järva green wedge will have lost a total of 3.84 km² buffer zones by the year 2030. The Corncrake and other grassland specialist species is likely to get most affected when grassland suffered the greatest habitat loss in the area. Even though the Eurasian jay has a key ecological function for the Oak forest in the Järva green wedge and relies on forest habitat for successful breeding, the loss of forest habitat will probably not affect the habitat generalist species in the same way. On a regional scale, the study suggests that habitat loss and fragmentation may affect grassland specialist species more than forest generalist species. The overall connectivity in the Järva green wedge is likely to get affected by a shrinking total area caused by narrowing of the green wedge until 2030. The function of the Järva green wedge as a dispersal corridor for biodiversity in the Stockholm region will most certainly get affected by further loss of buffer zones caused by exploitation of land for housing areas.

  • 15.
    Arra, Venni
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Storm Frequency in the Northern Baltic Sea Region and its Association to the North Atlantic Oscillation2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Storms can be both destructive and valuable at the same time. They expose coastal areas to various risks but can also enhance the supply of wind energy and provide marine ecosystems with oxygen rich water. As the North Atlantic Oscillation (NAO) is known to have a significant impact on the wind climate in Europe, investigating its interconnection to storm frequency and intensity under global warming circumstances in the Northern Baltic Sea region was of interest in this study. Wind speed data series of annual storm counts were obtained from five meteorological stations along with PC-based NAO values over the period 1960-2017. The data series were analysed in Microsoft Excel and modelled using a Poisson regression or negative binomial regression model in SPSS Statistics. The results display an unsystematic spatial pattern both in the association to the NAO as well as in the overall storm frequency. However, storm (≥ 21 m s-1) frequency has generally been decreasing, whereas the proportion of severe storms (≥ 24 m s-1) has slightly been increasing, suggesting a tendency toward stronger but fewer storms. Even though only certain data series display statistically significant findings (p ≤ .05), a majority of the winter storms and severe winter storms display a positive association, indicating that a higher NAOI is related to a greater number of winter storms. The spatial and temporal variability in the obtained results can partially be explained by storm tracks and prevalent wind directions. Nevertheless, inhomogeneities do presumably affect the wind speed observations through internal and external influences and changes related to the meteorological stations. Future research should, therefore, also consider integrating other storm related parameters, such as direct air pressure measurements, wave heights and storm surges, as well as implement different data homogenization methods and techniques.

  • 16.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Appendix to Paper V: Climate model performance versus basin-scalehydro-climatic dataManuscript (preprint) (Other academic)
  • 17.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Irrigation effects on hydro-climatic change: Basin-wise water balance-constrained quantification and cross-regional comparison2014In: Surveys in geophysics, ISSN 0169-3298, E-ISSN 1573-0956, Vol. 35, no 3, p. 879-895Article in journal (Refereed)
    Abstract [en]

    Hydro-climatic changes driven by human land and water use, including water use for irrigation, may be difficult to distinguish fromthe effects of global, natural and anthropogenic climate change. This paper quantifies and compares the hydro-climatic change effects ofirrigation using a data-driven, basin-wise quantification approach in two different irrigated world regions: the Aral Sea drainage basinin Central Asia, and the Indian Mahanadi River Basin draining into the Bay of Bengal. Results show that irrigation-driven changesin evapotranspiration and latent heat fluxes and associated temperature changes at the land surface may be greater in regions withsmall relative irrigation impacts on water availability in the landscape (here represented by the MRB) than in regions with severe suchimpacts (here represented by the Aral region). Different perspectives on the continental part of Earth’s hydrological cycle may thus implydifferent importance assessment of various drivers and impacts of hydro-climatic change. Regardless of perspective, however, actualbasin-wise water balance constraints should be accounted to realistically understand and accurately quantify continental water change.

  • 18.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Dutta, Dushmanta
    Analysis of water resources in the Mahanadi River Basin, India under projected climate conditions2008In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 22, no 18, p. 3589-3603Article in journal (Refereed)
    Abstract [en]

    The paper presents the outcomes of a study conducted to analyse water resources availability and demand in the Mahanadi River Basin in India under climate change conditions. Climate change impact analysis was carried out for the years 2000, 2025, 2050, 2075 and 2100, for the months of September and April (representing wet and dry months), at a sub-catchment level. A physically based distributed hydrologic model (DHM) was used for estimation of the present water availability. For future scenarios under climate change conditions, precipitation output of Canadian Centre for Climate Modelling and Analysis General Circulation Model (CGCM2) was used as the input data for the DHM. The model results show that the highest increase in peak runoff (38%) in the Mahanadi River outlet will occur during September, for the period 2075-2100 and the maximum decrease in average runoff (32·5%) will be in April, for the period 2050-2075. The outcomes indicate that the Mahanadi River Basin is expected to experience progressively increasing intensities of flood in September and drought in April over the considered years. The sectors of domestic, irrigation and industry were considered for water demand estimation. The outcomes of the analysis on present water use indicated a high water abstraction by the irrigation sector. Future water demand shows an increasing trend until 2050, beyond which the demand will decrease owing to the assumed regulation of population explosion. From the simulated future water availability and projected water demand, water stress was computed. Among the six sub-catchments, the sub-catchment six shows the peak water demand. This study hence emphasizes on the need for re-defining water management policies, by incorporating hydrological response of the basin to the long-term climate change, which will help in developing appropriate flood and drought mitigation measures at the basin level.

  • 19.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Vapor flux by evapotranspiration: effects of changes in climate, land-use and water-use2010In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 115, no D24Article in journal (Refereed)
    Abstract [en]

    Enhanced evapotranspiration (ET) over irrigated land and associated latent heat flux change can modify the climate. Model studies of such climate change effects of irrigation are commonly based on land use parameterizations, in terms of irrigated land area, or land area equipped for irrigation. Actual ET change, however, may also be driven by water use change in addition to land use change. This study quantifies and compares ET changes due to changes in climate, land use, and water use from the preirrigation period 1901–1955 to the recent period 1990–2000 (with irrigation) for the example case of Mahanadi River Basin (MRB) in India. The results show that actual water use per unit area of irrigated land may vary greatly over a hydrological drainage basin. In MRB, much higher water use per irrigated land unit in the downstream humid basin parts leads to higher vapor flux by ET, and irrigation‐induced ET flux change, than in the upstream, water‐stressed basin parts. This is consistent with water supply limitations in water‐stressed basins. In contrast, the assumption in land use−based models that irrigation maintains high soil moisture contents can imply higher modeled water use and therefore also higher modeled ET fluxes under dry conditions than under humid conditions. The present results indicate water use as an important driver of regional climate change, in addition to land use and greenhouse gas‐driven changes.

  • 20.
    Auffret, Alistair G.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Seed mobility and connectivity in changing rural landscapes2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world's most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that many plant species are left only on small fragments of former habitat. It is important that these plants can disperse, both for the maintenance of existing populations, and for the colonisation of target species to restored grasslands. This thesis investigates the ecological, geographical and historical influences on seed dispersal and connectivity in semi-natural grasslands, and the mobility of plants through time and space. Seed dispersal by human activity has played a large role in the build-up of plant communities in rural landscapes, but patterns have shifted. Livestock are the most traditional, and probably the most capable seed dispersal vector in the landscape, but other dispersal methods may also be effective. Motor vehicles disperse seeds with similar traits to those dispersed by livestock, while 39% of valuable grasslands in southern Sweden are connected by the road network. Humans are found to disperse around one-third of available grassland species, including several protected and red-listed species, indicating that humans may have been valuable seed dispersers in the past when rural populations were larger. Past activities can also affect seed mobility in time through the seed bank, as seeds of grassland plant species are shown to remain in the soil even after the grassland had been abandoned. Today however, low seed rain in intensively grazed semi-natural grasslands indicates that seed production may be a limiting factor in allowing seeds to be dispersed in space through the landscape.

  • 21.
    Baheram, Elina
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Nollalternativ i en miljökonsekvensbeskrivning2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study of the zero alternatives in an Environmental Impact Assessment (EIA) constitutes a thesis in the Master's program in Environmental Management and Physical Planning at the Department of Physical Geography and Quaternary Geology at Stockholm University. The work has also been produced in collaboration with WSP Civils.

    In the current situation, it seems to lack a clear consensus over how the zero alternatives in an EIA should be formulated and managed. The purpose of this study was to explore the attitudes towards the zero alternatives (or the no-action alternative) in an EIA and try to give a better understanding of how the alternative should be managed. Therefore, this study describes what the purpose and function of the zero alternatives have in an EIA, together with the aspects that should be considered when dealing with zero alternatives in an EIA.

    The study was conducted using four different methods that together should be able to answer the study's purpose and issues. To provide a better understanding the empirical data was connected to theories of prediction, uncertainties and scenarios in an EIA.

    The results of the study indicate that the purpose of the zero alternatives in an EIA is to put a plan or a project into context, and therefore fulfill an important function. It is important in an EIA to illustrate the uncertainty that exists in the predictions made about the future, which are the basis for the assessments that are made. This is also important for the zero alternatives. Regarding the uncertainty, it is also necessary to consider whether it in all circumstances is appropriate to use the zero alternatives as a reference alternative in relation to the other alternatives in the EIA. The Swedish Environmental Code also has two definitions that describe the zero alternatives, depending on whether it is a plan or a project the EIA should describe. This distinction is unfortunately not always visible in practice.

    During the study, it emerged that there is a demand for advice and recommendations for dealing with zero alternatives in an EIA. One hope is that this study will generate a greater knowledge of the handling of zero alternatives in an EIA.

  • 22. Baresel, Christian
    et al.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Uncertainty-Accounting Environmental Policy and Management of Water Systems2007In: Environmental Science & Technology, Vol. 41, no 10, p. 3653–3659-Article in journal (Refereed)
    Abstract [en]

    Environmental policies for water quality and ecosystem

    management do not commonly require explicit stochastic

    accounts of uncertainty and risk associated with the

    quantification and prediction of waterborne pollutant loads

    and abatement effects. In this study, we formulate and

    investigate a possible environmental policy that does require

    an explicit stochastic uncertainty account. We compare

    both the environmental and economic resource allocation

    performance of such an uncertainty-accounting environmental

    policy with that of deterministic, risk-prone and riskaverse

    environmental policies under a range of different

    hypothetical, yet still possible, scenarios. The comparison

    indicates that a stochastic uncertainty-accounting

    policy may perform better than deterministic policies over

    a range of different scenarios. Even in the absence of

    reliable site-specific data, reported literature values appear

    to be useful for such a stochastic account of uncertainty.

  • 23. Bendt, Pim
    et al.
    Barthel, Stephan
    Stockholm University, Faculty of Humanities, Department of History. Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Colding, Johan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Science, Beijer Institute of Ecological Economics, Sweden.
    Civic greening and environmental learning in public-access community gardens in Berlin2013In: Landscape and Urban Planning, ISSN 0169-2046, E-ISSN 1872-6062, Vol. 109, no 1, p. 18-30Article in journal (Refereed)
    Abstract [en]

    We analyse environmental learning in public-access community gardens (‘PAC-gardens’) in Berlin, representing public green spaces that are collectively managed by civil society groups. Through extensive fieldwork, and drawing upon social theories of learning, we describe learning communities in four PAC-gardens and analyse factors that influence participation and boundary interaction, that is when experiences brought in from the outside encounter socially defined competences. Results show that these PAC-gardens have self-generated social and physical structures, which to different degrees inhibit or facilitate boundary interactions, whereas skills of individuals to put those to work, in combination with the quality of the surrounding neighbourhoods, can be ascribed for creating broader participation and greater diversity in the content of learning about local sustainability. Identified learning streams included learning about gardening and local ecological conditions; about urban politics, and about social entrepreneurship. We discuss results in relation to environmental learning that combats the generational amnesia in cities about our dependence on nature, where PAC-gardens clearly distinguish themselves from more closed forms of urban gardening such as allotment gardens and gated community gardens. We conclude that PAC-gardens that intertwine gardening with social, political and economic practices can create broader and more heterogeneous learning about social–ecological conditions, and help develop sense-of-place in degraded neighbourhoods.

  • 24.
    Berencreutz, Magnus
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Ett paradigmskifte (?) i svensk geografi2014In: Geografiska Notiser, ISSN 0016-724X, Vol. 62, no 3, p. 127-136Article in journal (Other academic)
  • 25.
    Berggren, Anna
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Inledande försökt till mätning med Europas navigeringssystem Galileo2016Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Europe is presently building up a satellite navigation system of their own, Galileo. Unlike the American system, GPS, and the Russian system, Glonass, Galileo will be a civilian system. It will be independent from, but interoperable with both GPS and Glonass. After many delays have enough satellites been launched and placed in orbit to make it possible to start up Galileo’s initial services during December 2016.

    This study gives an account of the construction and development of the Galileo system. During two weeks in the spring 2016 experimental RTK measurements were made with Galileo combined with GPS where the satellite corrections were distributed from Lantmäteriet’s (the Swedish mapping, cadastral and land registration authority’s) supportsystem for satellite positioning, SWEPOS. The measurements were carried out with singlestation RTK towards a SWEPOS reference station at Mosebacke on Södermalm in Stockholm. The rover was placed over a fixed point about 1.2 km from the reference station.The purpose of the study was to determine if it was possible in the spring 2016 to make any measurements with Galileo and to see what Galileo can add to RTK measurements combined with GPS in SWEPOS.

    During the spring 2016 it was not possible to make any measurements with only Galileo satellites due to the fact that there were too few satellites in orbit. The results from the measurements indicate that combining Galileo and GPS could be positive for network RTK in SWEPOS. The part of achieved fixed solutions increases, the average time until fixed solution is achieved shortens and the space vehicle geometry (PDOP) gets a better value when combining GPS and Galileo. It is however too soon to say anything certain about the influence of Galileo on the position uncertainty.

  • 26.
    Bergsten, Arvid
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Zetterberg, Andreas
    To model the landscape as a network: A practitioner's perspective2013In: Landscape and Urban Planning, ISSN 0169-2046, E-ISSN 1872-6062, Vol. 119, p. 35-43Article in journal (Refereed)
    Abstract [en]

    Recent years have shown a rapid increase in the number of published studies that advocate network analysis (graph theory) to ecologically manage landscapes that suffer from fragmentation and loss of connectivity. This paper studies the reasons, benefits and difficulties of using network analysis to manage landscape fragmentation in the practice of land-use planning. The results are based on interviews with thirteen municipal ecologists and environmental planners in Stockholm, Sweden, who had been introduced to a GIS-tool for network-based connectivity analysis. Our results indicate that fragmentation is not considered enough in municipal planning and demonstrate that none of the interviewed practitioners used systematic methods to assess landscape connectivity. The practitioners anticipate that network-level and patch-level connectivity measures and maps would help them to communicate the meaning and implications of connectivity to other actors in the planning process, and to better assess the importance of certain habitats affected by detailed plans. The main difficulties of implementing network-based connectivity analyses reported by the respondents related to the choice of focal species and the lack of model input in terms of landscape data and dispersal distances. The main strengths were expressed by the practitioners as graphical, quantitative and credible results; the ability to compare planning alternatives and to find critical sites in a more objective manner than today; and to relate local planning and ecology to the regional structure of the landscape. Many respondents stressed the role of fragmentation assessments in the endeavor to overcome current spatial mismatches of ecological and administrative scales.

  • 27.
    Bergström, Erik
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Den prerecenta lokalglaciationens utbredningshistoria inom Skanderna: The history of the pre-recent local glaciation in the Scandinavian mountains1973Doctoral thesis, monograph (Other academic)
  • 28.
    Berntsson, Annika
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Rosqvist, Gunhild C.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Velle, Gaute
    Late-Holocene temperature and precipitation changes in Vindelfjallen, mid-western Swedish Lapland, inferred from chironomid and geochemical data2014In: The Holocene, ISSN 0959-6836, E-ISSN 1477-0911, Vol. 24, no 1, p. 78-92Article in journal (Refereed)
    Abstract [en]

    In this article, we present results from a palaeolimnological study from Lake Vuoksjavratje in the mountain tundra region in the Vindelfjallen Mountains, northwest Sweden. We suggest that the influence of precipitation may be one of the factors causing discrepancies between chironomid-based late-Holocene July temperature (JulyT) reconstructions from Fennoscandia. We combine quantitative temperature reconstruction using chironomids for the last 5100 years with qualitative analysis of chironomid composition and geochemical analyses, such as x-ray fluorescence (XRF), total organic carbon (TOC) and C/N analysis. The studied sequence is dated by Pb-210, Cs-137 and 11 C-14 datings from terrestrial macrofossils. The aim of the study was to use chironomids to reconstruct late-Holocene summer temperature variation on a multi-centennial to centennial timescale and to use geochemical data to identify periods during which the changes in chironomid composition might have been forced by environmental variables other than temperature, such as within lake processes or precipitation. Based on ordination techniques, and a comparison between chironomid-inferred JulyTs and changes in minerogenic sedimentation with regional temperature and wetness records, it is concluded that the JulyT signal was modulated by precipitation. The proxies indicate that both JulyT and annual precipitation have influenced the chironomid communities in Lake Vuoksjavratje, and that catchment-related processes caused by enhanced precipitation have overridden the summer temperature signal between 3000 and 2200 cal. yr BP, and between 1050 and 100 cal. yr BP.

  • 29. Bigg, G. R.
    et al.
    Clark, C. D.
    Greenwood, Sarah L.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Haflidason, H.
    Hughes, A. L. C.
    Levine, R. C.
    Nygard, A.
    Sejrup, H. P.
    Sensitivity of the North Atlantic circulation to break-up of the marine sectors of the NW European ice sheets during the last Glacial: A synthesis of modelling and palaeoceanography2012In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364, Vol. 98-99, p. 153-165Article in journal (Refereed)
    Abstract [en]

    The marine-based Atlantic periphery of the last NW European Ice Sheet experienced significant advances and retreats of its marine sector during its existence. It therefore had considerable potential to intermittently inject freshwater or ice pulses to the North Atlantic. These European inputs had poorly known consequences for ocean circulation and climate. Here we examine the history of the western margin of the European Ice Sheet, from 34 to 15 cal ka BP, and use a combination of modelling and proxy evidence to explore the impact on the North Atlantic of the fresh water and iceberg injections that accompanied phases of retreat of the marine sector of the NW European Ice Sheet. We find that the lack of geographical synchronicity in the responses of the different components of the 3000 km long sector meant that the scale of the climate consequences of ice discharge most likely remained regional, except during the final deglaciation phase, around 17-15 cal ka BP. At this time, as the later component of the recently introduced concept of an extended Heinrich event H1, both proxy and modelling evidence suggest rapid sector collapse led to partial shut-down of the Atlantic overturning and a basin-wide cooling.

  • 30. Bishop, Paul
    et al.
    Jansen, John
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Castillo, Miguel
    Reinhardt, Liam
    Whitbread, Katie
    Kim, Jong-Yong
    Fabel, Derek
    Hoey, Trevor
    ‘Bottom-up’ bedrock river response to rock uplift: Unravelling the controls of landscape responses to transience.2010In: British Society for Geomorphology Programme & Abstracts. London, England, Aug 2010., 2010Conference paper (Other academic)
    Abstract [en]

    Bedrock rivers set the boundary conditions for landscape evolution. Most recent bedrock river research has been in steady-state settings in which rock uplift is matched by landscape lowering driven by bedrock river incision and slope lowering, but more attention is now being paid to bedrock rivers is transient settings (where transience in the fluvial system is triggered by changes in the rate of rock uplift and/or by climatic oscillations).  Transient responses in bedrock rivers close to base-level are dominated by ‘bottom-up’ processes.  Those processes remain less well understood than the ‘top-down’ processes that are thought to be characteristic of steady state landscapes and are driven by discharges of water and sediment. Key issues in understanding rates of landscape-wide response to transience are (i) rates of knickpoint retreat to transmit a base-level fall signal through the drainage net, and (ii) rates of hillslope response once that base-level fall has passed the foot of a hillslope.  Terrestrial cosmogenic nuclide (TCN) data from a transient landscape in southern Spain point to the latter being the rate-limiting control (“fast rivers, slow hillslopes”).  In terms of the former, morphometric and TCN data from coastal rivers in Scotland confirm knickpoint retreat in response to glacio-isostatic rebound, whereas TCN data from higher up these rivers, above the reach affected by glacio-isostatic base-level fall, point to more diffusive bedrock channel incision, without knickpoint retreat.  Determining why diffusive incision is initiated at a particular locality in those settings is difficult but in at least one case the incision is probably ‘pinned’ on resistant lithologies.  A wider and more taxing issue is the relationship between ‘bottom-up’ and ‘top-down’ incisional processes and whether the former must precede, and can evolve into, the latter.

     

  • 31. Björk, Alexandra
    et al.
    Skånes, Helle
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The Need for Awareness of Semantic Plasticity in International Harmonization of Geographical Information: Seen from a Nordic Forest Classification Perspective2015In: Land Use and Land Cover Semantics: Principles, Best Practices and Prospects / [ed] Ola Ahlqvist, Dalia Varanka, Steffen Fritz, Krzysztof Janowicz, Boka Raton: CRC Press, 2015, p. 41-58Chapter in book (Refereed)
    Abstract [en]

    The aim of this chapter is to address and clarify the important issues and challenges of semantic plasticity when it comes to forest classification and geographical information. Necessary improvements for international data harmonization and implementation are highlighted along with the need for increased awareness of the consequences for ecological modeling. We envisage a combination of thoroughly described metadata and controlled vocabularies as a means to ensure the future use of a wide range of regional and national classification systems in an ontological framework that enables crosswalks between classification systems and spatial comparisons between existing data sets. This would allow for a wide range of old, contemporary, and future data sets to be used together in landscape-related analyses.

  • 32. Björk, Alexandra
    et al.
    Skånes, Helle
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Ahlqvist, Ola
    Ser vi skogen för alla träd? Vikten av semantisk plasticitet vid harmonisering av geodata2015In: Sinus, no 4, p. 2Article in journal (Other (popular science, discussion, etc.))
  • 33.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Deglaciationsförloppet och Isdämda sjöar i Vindelälvens källområde2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A detailed landform mapping was carried out in the mountain region of the source area of River Vindelälven. The aim of this mapping study was to increase the current knowledge of the dynamics and character (the ice margin retreat, ice flow directions and the subglacial thermal organization) of the Fennoscandian Ice Sheet during the last deglaciation in this part of the Swedish mountain range.

    The study area has been proposed to be situated within the cold based core area that characterized the last Ice age maxima (LGM). However, despite the lack of subglacial melting, glacial meltwater still exists. Traces after ancient glacial lakes and the glaciofluvial landform system are therefore the only data that exist when reconstructing the recession pattern of cold based ice sheets or when there is a general lack of glacial landforms.

    The aerial photograph interpretation focused on glaciolacustrine, glaciofluvial and subglacial landforms. The reconstruction of the ice sheet recession pattern was thus based on the distribution of the glacial geomorphology, the dammed glacial lakes and the hypothetical damming ice sheet margin. A theoretical model for calculation of the ice surface slope profile was used to increase the detail level of the reconstruction and as a control of the landform based reconstruction. Mapped landforms formed the base for the glacial lake reconstruction that was carried out in a GIS. Lantmäteriets height database was used as a topographical base dataset.

    Ice sheet margins reconstructed by the theoretical model showed good conformity with the mapped landforms. Eight glacial lakes where identified, two of these, Glacial lake Vindelälven and Glacial lake Båssjuosjávrrie – Gávásjávrries, existed with large safety and where dominant features in the landscape during the deglaciation. They where dammed in the northwest and west respectively between revealed saddle points in the terrain and the retreating ice sheet.

    The damming of large glacial lakes shows that the ice sheet, in the study area, was active throughout the entire deglaciation. The ice sheet retreated generally towards the southeast. The presented deglaciation model indicated northwesterly and westerly ice flow directions in an early phase of the deglaciation, and westerly in a late phase. The last ice flow direction in the study area was towards west and it stemmed probably from the last ice divide situated above the low fell Kráhpiesvarrie. The subglacial thermal organization in the study area may be viewed as uncertain due to ambiguous evidence.

  • 34.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Paleoglaciology of the Tian Shan and Altai Mountains, Central Asia2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The mountain-systems of Central Asia, act as barriers to atmospheric circulation patterns, which in turn impose striking climate gradients across the region. Glaciers are sensitive indicators of climate change and respond to changes in climate gradients over time by advancing during cold and wet periods and receding during warm and dry periods. The aim of this thesis is to investigate whether there are large-scale patterns in how past glaciers in the Tian Shan and the Altai Mountains of Central Asia responded to climate change. Multiple methods have been used, including: remote sensing, terrain analysis, field investigations, and cosmogenic nuclide (CN) dating. The glacial landform records indicate that the region experienced mainly alpine-style glaciations in the past. Large complexes of ice-marginal moraines in high elevation basins are evidence of outlet glaciers sourced from large valley glaciers, ice caps and ice-fields, and these moraine sequences, record the maximum extent of paleoglaciation. In the Ikh-Turgen Mountains, located in the continental, eastern Altai Mountains, deglaciation of these moraines occurred during marine oxygen isotope stage (MIS) 3 at ~45 ka. This is consistent with a colder and wetter climate during this time, inferred from ice core and lake level proxies. Another deglacial phase occurred during MIS 2 at ~23 ka, synchronous with the global Last Glacial Maximum. In the Russian Altai Mountains, lobate moraines in the Chuya Basin indicate deglaciation at ~19 ka, by a highly dynamic paleoglacier in the Chagan-Uzun catchment, which experienced surge-like behaviour. Furthermore, across the Tian Shan, an evaluation of new and existing CN glacial chronologies (25 dated moraines) indicates that only one regional glacial stage, between 15 and 28 ka (MIS 2), can be defined and spatially correlated across the region. These paleoglaciers were mainly restricted to valleys as a result of arid conditions during this time and variation in their extents is interpreted to reflect topographic modulation on regional climate. The ages of the oldest evidence for robust local glacial stages in the Tian Shan are not yet well constrained, however, moraines in the central Kyrgyz Tian Shan and the eastern Chinese Tian Shan have apparent minimum ages overlapping with MIS 5 and MIS 3 (with missing MIS 4 and 6 stages). However, different geological processes, such as inheritance and post-depositional shielding (e.g. deposition by surging glaciers or hummocky terrain deposition), have influenced the dating resolution, making several moraine ages inappropriate for regional comparison. Finally, to quantify regional patterns of paleoglaciation, the hypsometry (area-elevation distribution) of glacial landforms is used to estimate average paleo equilibrium line altitudes for the region. This analysis shows that while present-day ELAs mirror strong climate gradients, paleoglaciation patterns were characterised by more gentle ELA gradients. The paleo-ELA depressions across Central Asia were most prominent in the continental southern and eastern regions (500–700 m). Finally, the results from this thesis, show that Central Asia was repeatedly glaciated in the past, but underscore the importance of considering 1) catchment characteristics and styles of glaciation and 2) other non-climatic factors controlling glacier dynamics when interpreting CN chronologies to make paleoclimate inference.

  • 35.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University.
    The Late Glacial History of the Magellan Strait in southern Patagonia, Chile: Testing the Applicability of KF-IRSL Dating2012Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The timing of the ice margin retreat of the Late Glacial Patagonian ice sheet (PIS) in southern Patagonia has been the object of discussion for many years. In order to resolve questions about the complex response of the PIS to past climate change; geological interpretation and modelling data needs evaluation against absolute chronology. The aim of this project is to re-map the landforms and sediment of the Magellan Strait, to reconstruct the late glacial ice retreat during the deglaciation and to investigate the applicability of OSL dating to glaciofluvial sediment from this region. Unfortunately previous studies have shown that the quartz OSL luminescence characteristics, of this region, are unsuitable for dating. Therefore the potential of K-feldspar IRSL signals are reviewed and examined. Samples were collected from landforms interpreted as being deposited during the deglaciation of the Magellan ice lobe, with an expected age range between 17.5 and 23 ka, and from recently deposited sediments (<1 ka). Small aliquots and single grain distributions were studied by applying a IR50 SAR protocol with IRSL stimulation at 50°C for 100 s and a preheat of 250 °C (held at 60 s) are measured.  Appropriate uncertainties were assigned to the dose distribution data, by quantifying the laboratory over-dispersion (σOD) parameter (22.2% for small aliquots and 17.7 % for single grains) in laboratory bleached and γ-irradiated samples.  Thereafter the possible effects of incomplete bleaching and anomalous fading were examined. For the natural samples environmental over-dispersions between 30–130 % and mean interpreted residual doses between ~30 and 80 Gy were observed. Statistical models were further applied to identify the part of the dose population that was most likely to have been completely bleached. The models are consistent with each other which imply that they successfully identified the fully-bleached grains in the distributions; however observed discrepancies between the small aliquot and single grain data were also discussed. Large g2day values (on average 7.92±0.6%/decade for large aliquots) were observed but nevertheless, comparing our fading corrected ages to the expected age range result in 2 out of 3 ages consistent with geological interpretation and an established radiocarbon and cosmogenic nuclide chronology suggesting that this correction was done successfully. The results of these investigations suggest that small aliquot/single grain fading can be corrected for using an average value and that KF-IRSL dating is applicable in this part of Southern Patagonia. The third age is supported by an alternative geological interpretation while the two consistent ages imply that in the Magellan Strait the hills of the Brunswick peninsula (70-100 m.a.s.l) were deglaciated at around ~21 ka. Finally some recommendations for future research are considered.

  • 36.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. Purdue University, USA.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. Purdue University, USA.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jansson, Krister N.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Petrakov, Dmitry A.
    Ivanov, Mikhail N.
    Alexander, Orkhonselenge
    Rudoy, Alexei N.
    Walther, Michael
    Glacial geomorphology of the Altai and Western Sayan Mountains, Central Asia2016In: Journal of Maps, ISSN 1744-5647, E-ISSN 1744-5647, Vol. 12, no 1, p. 123-136Article in journal (Refereed)
    Abstract [en]

    In this article, we present a map of the glacial geomorphology of the Altai andWestern Sayan Mountains, covering an area of almost 600,000 km2. Although numerous studies provide evidence for restricted Pleistocene glaciations in this area, others have hypothesized the past existence of an extensive ice sheet. To provide a framework for accurate glacial reconstructions of the Altai and Western Sayan Mountains, we present a map at a scale of 1:1,000,000 based on a mapping from 30 m resolution ASTER DEM and 15 m/30 mresolution Landsat ETM+ satellite imagery. Four landform classes have been mapped: marginal moraines, glacial lineations, hummocky terrain, and glacial valleys. Our mapping reveals an abundance of glacial erosional and depositional landforms. The distribution of these glacial landforms indicates that the Altai and Western Sayan Mountains have experienced predominantly alpine-style glaciations, with some small ice caps centred on the higher mountain peaks. Large marginal moraine complexes mark glacial advances in intermontane basins. By tracing the outer limits of present-day glaciers, glacial valleys, and moraines, we estimate that the past glacier coverage have totalled to 65,000 km2 (10.9% of the mapped area), whereas present-day glacier coverage totals only 1300 km2 (0.2% of the mapped area). This demonstrates the usefulness of remote sensing techniques for mapping the glacial geomorphology in remote mountain areas and for quantifying the past glacier dimensions. The glacial geomorphological map presented here will be used for further detailed reconstructions of the paleoglaciology and paleoclimate of the region.

  • 37.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Caffee, Marc W.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogozhina, Irina
    Ivanov, Mikhail N.
    Petrakov, Dmitry A.
    Walther, Michael
    Rudoy, Alexei N.
    Zhang, Wei
    Orkhonselenge, Alexander
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lifton, Nathaniel A.
    Jansson, Krister N.
    Paleoglaciation on opposite flanks of the Ikh-Turgen Mountains, Central Asia: Importance of style of moraine deposition for 10-Be surface exposure datingManuscript (preprint) (Other academic)
    Abstract [en]

    The ages of marginal moraines that record extensive glacier expansions across the Altai Mountains of Central Asia are poorly documented. We present 18 10Be exposure ages from moraines in valleys on opposite flanks of the Ikh-Turgen Mountains. On the eastern side, exposure ages from a latero-frontal moraine indicate deglaciation during MIS 3 (45.3±2.7 ka) and MIS 2 (22.8±3.5 ka). Corresponding exposure ages, from the western side, indicate a more complex story with large scatter (~14-53 ka). Owing to their close proximity, the paleoglaciers should have responded similarly to climate forcing, yet they exhibited a distinctly different behavior. We propose that differences in glacier dynamics caused differences in ice-marginal depositional environments, explaining the scatter in exposure ages on the western side. This study shows the importance of style of deposition in chronological studies of glacial landforms and demonstrates that certain moraine types can be difficult to use as paleoclimate proxies.

  • 38.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Topographic and climatic controls on paleoglaciation patterns across the Tian Shan and Altai Mountains, Central AsiaManuscript (preprint) (Other academic)
    Abstract [en]

    Reconstructing spatial patterns of the extents and dynamics of paleoglaciers across Central Asia is key in understanding the mechanisms of global environmental change. The Tian Shan and Altai Mountains are located in the continental interior of Eurasia, at the confluence of several major climate systems. In order to test hypothesized patterns in paleoglacier extent, and to test the role of paleoclimate and mountain topography in modulating the evolution of these glacial systems, we perform a domain-wide terrain analysis. We first divide the Tian Shan and the Altai Mountains into six physiographic regions delineated by major drainage divides and outlining generalised climate zones. Thereafter we mine published datasets on the distribution of glaciers and glacial landforms, calculate their area-elevation distributions (hypsometry), and extract present-day regional equilibrium line altitudes (ELAs) and long-term average ELAs (paleo-ELAs). We show that the use of glacial landform hypsometry is an effective tool to quantify broad-scale paleoglaciation patterns and find that there is a regional variability in glacier extents across the Tian Shan and Altai Mountains. Reconstructed ELAs show pronounced spatial gradients; increasing ELAs from northern to southern Tian Shan, and increasing ELAs from the northern to both the southeastern and southwestern Altai Mountains. In contrast, maximum paleoglaciation patterns and paleo-ELAs were more uniform across the two mountain systems, with inter-regional topographic variability influencing moraine distributions and thus complicating regional paleo-ELA determinations. Because estimated paleo-ELAs were relatively uniform across the Tian Shan and Altai Mountains, the paleo-ELA lowering were most pronounced in the more continental southern and eastern regions. Our current data is insufficient to explain whether this observation is the result of a different regional paleoclimatic regime than today, or if paleoglaciers responded dynamically different to a paleoclimate forcing of the same magnitude. Our ELA reconstructions also lack temporal constraints, so we furthermore propose that future studies systematically compare hypsometry-derived ELA reconstructions with those stemming from surface energy mass balance models, other proxy records (i.e. lake- and ice core records), and from chronologically constrained ice-marginal moraines.  

  • 39.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lifton, Nathaniel A.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Petrakov, Dmitry A.
    Caffee, Marc W.
    Ivanov, Mikhail N.
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogozhina, Irina
    Usubaliev, Ryskul
    Evaluating the timing of former glacier expansions in the Tian Shan: a key step towards robust spatial correlationsIn: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457XArticle in journal (Refereed)
    Abstract [en]

    The timing of past glaciation across the Tian Shan provides a proxy for past climate change in this critical area. Correlating glacial stages across the region is difficult but cosmogenic exposure ages have considerable potential. A drawback is the large observed scatter in 10Be surface exposure data. To quantify the robustness of the dating, we compile, recalculate, and perform statistical analyses on sets of 10Be surface exposure ages from 25 moraines, consisting of 114 new and previously published ages. We assess boulder age scatter by dividing boulder groups into quality classes and rejecting boulder groups of poor quality. This allows us to distinguish and correlate robustly dated glacier limits, resulting in a more conservative chronology than advanced in previous publications. Our analysis shows that only one regional glacial stage can be reliably correlated across the Tian Shan, with glacier expansions occurring between 15 and 28 ka during marine oxygen isotope stage (MIS) 2. However, there are examples of older more extensive indicators of glacial stages between MIS 3 and MIS 6. Paleoglacier extent during MIS 2 was mainly restricted to valley glaciation. Local deviations occur: in the central Kyrgyz Tian Shan paleoglaciers were more extensive and we propose that the topographic context explains this pattern. Correlation between glacial stages prior to late MIS 2 is less reliable, because of the low number of samples and/or the poor resolution of the dating. With the current resolution and spatial coverage of robustly-dated glacier limits we advise that paleoclimatic implications for the Tian Shan glacial chronology beyond MIS 2 are speculative and that continued work toward robust glacial chronologies is needed to resolve questions regarding drivers of past glaciation in the Tian Shan and Central Asia. 

  • 40.
    Bogren, Fredrik
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Evidence for birch forests and a highly productive environment near the margin of the Fennoscandian ice sheet in the Värriötunturit area, northeastern Finland2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    High-resolution records of early Holocene deposits are rare, and as a consequence reconstruction of terrestrial environments very soon after the deglaciation has often been difficult. In this study the palaeoenvironmental conditions of early Holocene (c. 10600-7500 cal. yr BP) are reconstructed in the Värriötunturit area of northeastern Finland, using evidence from plant macrofossils and pollen preserved in a lake sediment sequence retrieved from the small lake Kuutsjärvi. Special emphasis is put on the environment immediately following the deglaciation as the base of the sediment sequence is rich in minerogenic material interpreted to have been deposited by meltwater pulses from the retreating ice sheet. The abundance and variety of fossil remains in these early meltwater deposits provide evidence for a very productive ice-marginal environment in the area between the lake and the ice sheet, and the presence of tree-type Betula macro remains as well as high percentage values of tree-type Betula pollen suggests that a subarctic birch forest established just a few years after the deglaciation. In the following centuries the birch forest around the lake became rich in an under growth of ferns, and at c. 9400 cal. yr BP a transition into a mixed pine and birch forest took place. Due to absence of indicator plant taxa in the sediment it was not possible to reconstruct temperature conditions for any parts of the sequence in this study. However, the rapid colonisation of birch forests suggests that the climate was warm already during deglaciation, which is also in accordance with climatic conditions reconstructed for the early Holocene in the nearby Sokli area just 10 km away, as well as in other parts of Fennoscandia and Russia.

  • 41. Bonow, Johan M.
    et al.
    Japsen, Peter
    Green, Paul F.
    Wilson, Robert W.
    Chalmers, James A.
    Klint, Knud Erik S.
    Gool, Jeroen A.M.
    Lidmar-Bergström, Karna
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Pedersen, Asger Ken
    A multi-disciplinary study of Phanerozoic landscape development in West Greenland2007In: Geological Survey of Denmark and Greenland Bulletin: Review of Survey activities 2006, ISSN 1604-8156, no 13, p. 33-36Article in journal (Refereed)
    Abstract [en]

    The western margin of the Greenland craton has been much

    less stable in the Phanerozoic than previously thought. This

    new insight has come from close integration of independent

    data sets: geomorphological analysis of large-scale landscapes,

    apatite fission track analysis (AFTA), onshore and offshore

    stratigraphy and analysis of onshore fault and fracture sys -

    tems. Each data set records specific and unique parts of the

    event chronology and is equally important to establish a con-

    sistent model. A key area for understanding the Mesozoic-

    Cenozoic landscape evolution and into the present is the

    uplifted part of the Nuussuaq Basin, where remnants of pla-

    nation surfaces cut across the Cretaceous to Eocene sedimen-

    tary and volcanic rocks. Our integrated analysis concluded

    that the West Greenland mountains were formed by late

    Neogene tectonic uplift (Fig. 1) and also provided new

    insight into early Phanerozoic development. To understand

    our model, we present the different methods and the results

    that can be deduced from them.

  • 42.
    Bonow, Johan M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Japsen, Peter
    Lidmar-Bergström, Karna
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Chalmers, James A.
    Pedersen, Asger Ken
    Cenozoic uplift of Nuussuaq and Disko, West Greenland: elevated erosion surfaces as uplift markers of a passive margin2006In: Geomorphology, ISSN 0169-555X, E-ISSN 1872-695X, Vol. 80, no 3-4, p. 325-337Article in journal (Refereed)
    Abstract [en]

    Remnants of a high plateau have been identified on Nuussuaq and Disko, central West Greenland. We interpret the plateau as an erosion surface (the summit erosion surface) formed mainly by a fluvial system and graded close to its former base level and subsequently uplifted to its present elevation. It extends over 150 km east–west, being of low relative relief, broken along faults, tilted westwards in the west and eastwards in the east, and having a maximum elevation of ca. 2 km in central Nuussuaq and Disko. The summit erosion surface cuts across Precambrian basement rocks and Paleocene–Eocene lavas, constraining its age to being substantially younger than the last rift event in the Nuussuaq Basin, which took place during the late Maastrichtian and Danian. The geological record shows that the Nuussuaq Basin was subjected to subsidence of several kilometres during Paleocene–Eocene volcanism and was transgressed by the sea later during the Eocene. By comparing with results from apatite fission track analysis and vitrinite reflectance maturity data, it is suggested that formation of the erosion surface was probably triggered by an uplift and erosion event starting between 40 and 30 Ma. Surface formation was completed prior to an uplift event that started between 11 and 10 Ma and caused valley incision. This generation of valleys graded to the new base level and formed a lower erosion surface, at most 1 km below the summit erosion surface, thus indicating the magnitude of its uplift. Formation of this generation of valleys was interrupted by a third uplift event also with a magnitude of 1 km that lifted the landscape to near its present position. Correlation with the fission-track record suggests that this uplift event started between 7 and 2 Ma. Uplift must have been caused initially by tectonism. Isostatic compensation due to erosion and loading and unloading of ice sheets has added to the magnitude of uplift but have not significantly altered the configuration of the surface. It is concluded that the elevations of palaeosurfaces (surfaces not in accordance with present climate or tectonic conditions) on West Greenland's passive margin can be used to define the magnitude and lateral variations of Neogene uplift events. The striking similarity between the landforms in West Greenland and those on many other passive margins is also noted.

  • 43.
    Bonow, Johan M.
    et al.
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Lidmar-Bergström, Karna
    Department of Physical Geography and Quaternary Geology.
    Japsen, Peter
    Chalmers, James A.
    Green, Paul F.
    Elevated erosion surfaces in central West Greenland and southern Norway: their significance in integrated studies of passive margin development2007In: Norwegian Journal of Geology, ISSN 0029-196X, Vol. 87, p. 197-206Article in journal (Refereed)
    Abstract [en]

    Elevated erosion surfaces were used as an independant data set in an integrated study of the landscape development in central West Greenland. The study resulted in a time-constrained model describing multiple episodes of post-rift uplift, erosion and burial on a passive margin. The model is based on full integration of three data sets: analysis of large-scale landforms, apatite fission track analysis (AFTA) of samples from outcrops and deep boreholes, and the geological record. These data are equally important as they record specific an unique parts of the landscape history. The relative chronology obtained from the landform record is constrained by geology, which gives the maximum age of an erosin surface, and AFTA that records the cooling history of the subsurface rock. This combined approach validates the interpretation of erosion surface as having been goverened by different base levels in the past, and shows that erosion surfaces can be used to reconstruct tectonic events. Geomorphological key observations for the landscapes of southern Norway are presented and the similarities with landscapes in central West Greenland emphasised, especially the elevated plateaux and the Mesozoic etch surfaces. This similarity suggests that it may be possible to construct a time-constrained model for the landscape development of southern Norway based on our West Greenland approach.

  • 44.
    Bonow, Johan Mauritz
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Lidmar-Bergström, Karna
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Näslund, Jens-Ove
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Palaeosurfaces and major valleys in the area of Kjølen Mountains, southern Norway: consequences of uplift and climatic change2003In: Norsk Geografisk Tidsskrift, ISSN 0029-1951, E-ISSN 1502-5292, Vol. 57, no 2, p. 83-101Article in journal (Refereed)
  • 45. Booth, Adam D.
    et al.
    Mercer, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Clark, Roger
    Murray, Tavi
    Jansson, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Axtell, Charlotte
    A comparison of seismic and radar methods to establish the thickness and density of glacier snow cover2013In: Annals of Glaciology, ISSN 0260-3055, E-ISSN 1727-5644, Vol. 54, no 64, p. 73-82Article in journal (Refereed)
    Abstract [en]

    We show that geophysical methods offer an effective means of quantifying snow thickness and density. Opportunistic (efficient but non-optimized) seismic refraction and ground-penetrating radar (GPR) surveys were performed on Storglaciaren, Sweden, co-located with a snow pit that shows the snowpack to be 1.73 m thick, with density increasing from similar to 120 to similar to 500 kg m(-3) (with a +50 kg m(-3) anomaly between 0.73 and 0.83 m depth). Depths estimated for two detectable GPR reflectors, 0.76 +/- 0.02 and 1.71 +/- 0.03 m, correlate extremely well with ground-truth observations. Refraction seismic predicts an interface at 1.90 +/- 0.31 m depth, with a refraction velocity (3730 +/- 190 m s(-1)) indicative of underlying glacier ice. For density estimates, several standard velocity-density relationships are trialled. In the best case, GPR delivers an excellent density estimate for the upper snow layer (observed = 321 +/- 74 kg m(-3), estimated = 319 +/- 10 kg m(-3)) but overestimates the density of the lower layer by 20%. Refraction seismic delivers a bulk density of 404 +/- 22 kg m(-3) compared with a ground-truth average of 356 +/- 22 kg m(-3). We suggest that geophysical surveys are an effective complement to mass-balance measurements (particularly for controlling estimates of snow thickness between pits) but should always be validated against ground-truth observations.

  • 46.
    Borén, Thomas
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Bonniers uppslagsbok2007Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    I Bonniers uppslagsbok (2007) har författaren skrivit uppslagsorden inom ämnesområdet svensk geografi (från I till Ö).

  • 47.
    Borén, Thomas
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Fridfeldt, Anders
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Kinlund, Peter
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Sannel, Britta
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Introduction2007In: Geographical studies in Aotearoa 2006: report from a geographical field course in New Zealand, March 2006 / [ed] Thomas Borén, Stockholm: Kulturgeografiska inst. & Naturgeografiska inst., Stockholms universitet , 2007, , p. 1-4p. 1-4Chapter in book (Other academic)
    Abstract [en]

    A short introduction to the excursions and fieldwork that are part of the Advanced level Geography courses at Stockholm University. After the introduction follows seven bachelor theses in Geography, empirically based on fieldwork in Wanaka and Queenstown, New Zealand, March 2006.

  • 48.
    Borén, Thomas
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Fridfeldt, Anders
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Kinlund, Peter
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Sannel, Britta
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hultblad, Gertrud
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Geographical studies in Aotearoa 2006: Report from a geographical field course in New Zealand, March 2006.2007Report (Other academic)
    Abstract [sv]

    Rapporten innehåller sju stycken uppsatser av studenter på påbyggnadskursen (C-kursen) i Geografi vid Stockholms universitet. Samtliga uppsatser är baserade på eget fältarbete i Queenstown och Wanaka, Nya Zeeland, i mars 2006. Temat för uppsatserna varierar och de behandlar: urbana strukturer, platsidentitet, platskänsla, vingårdar och vinturism, ekoturism, äventyrsturism, samt migration mellan små städer. Uppsatserna föregås av en kort introduktion på engelska om geografiprogrammets exkursioner och fältkurser av Thomas Borén, Anders Fridfeldt, Peter Kinlund och Britta Sannel.

  • 49.
    Borén, Thomas
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Schlyter, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Beringia - en region?: Introduktion till en relationell regionalgeografi.2008In: Kring Beringia.: Expeditioner och folk., SSAG, Stockholm , 2008, p. 7-18Chapter in book (Other academic)
    Abstract [sv]

    Beringia - en region? är introduktionen till antologin Kring Beringia. Expeditioner och folk. Introduktionen behandlar regionbegreppet, relationella rum och sovjetisk geografi, samt sammanfattar kort de olika kapitelbidragen.

  • 50.
    Borén, Thomas
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Schlyter, PeterStockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Kring Beringia.: Expeditioner och folk.2008Collection (editor) (Other academic)
    Abstract [sv]

    I Kring Beringia behandlar en internationell samling geografer och andra forskare och skribenter frågor om samhälle, miljö och resurser i Beringregionen, med tungdpunkt på den ryska delen.

    Kapitelförfattare är Thomas Borén och Peter Schlyter, Kristian Gerner, John Round, Jessica Graybill, Bente Eriksen, Elinor Andrén, Lada Lekai, Mikael Strandberg, samt Carl Johan Gurt.

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