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  • 1.
    Bosson, Emma
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK). Swedish Nuclear Fuel and Waste Management Company, Stockholm, Sweden.
    Sabel, Ulrika
    Gustafsson, Lars-Göran
    Sassner, Mona
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Influences of shifts in climate, landscape, and permafrost on terrestrial hydrology2012Ingår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 117, artikel-id D05120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study has simulated the terrestrial hydrology associated with different climate, landscape, and permafrost regime scenarios for the field case example of the relatively well characterized coastal catchment of Forsmark, Sweden. The regime scenarios were selected from long-term simulation results of climate, topographical, shoreline, and associated Quaternary deposit and vegetation development in this catchment with a time perspective of 100,000 years or more and were used as drivers for hydrological simulations with the three-dimensional model MIKE SHE. The hydrological simulations quantify the responses of different water flow and water storage components of terrestrial hydrology to shifts from the present cool temperate climate landscape regime in Forsmark to a possible future Arctic periglacial landscape regime with or without permafrost. The results show complexity and nonlinearity in the runoff responses to precipitation changes due to parallel changes in evapotranspiration, along with changes in surface and subsurface water storage dynamics and flow pathways through the landscape. The results further illuminate different possible perspectives of what constitutes wetter/drier landscape conditions, in contrast to the clearer concept of what constitutes a warmer/colder climate.

  • 2.
    Bosson, Emma
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Selroos, Jan-Olof
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Stigsson, Martin
    Gustafsson, Lars-Göran
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Exchange and pathways of deep and shallow groundwater in different climate and permafrost conditions using the Forsmark site, Sweden, as an example catchment2012Ingår i: Hydrogeology Journal, ISSN 1431-2174, E-ISSN 1435-0157, Vol. 21, nr 1, s. 225-237Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study simulates and quantifies the exchange and the pathways of deep and shallow groundwaterflow and solute transport under different climate and permafrost conditions, considering the example field case of the coastal Forsmark catchment in Sweden. A number of simulation scenarios for different climate and permafrost condition combinations have been performed with the three-dimensional groundwater flow and transport model MIKE SHE. Results show generally decreasing vertical groundwater flow with depth, and smaller vertical flow under permafrost conditions than under unfrozen conditions. Also the overall pattern of both the vertical and the horizontal groundwater flow, and the water exchange between the deep and shallow groundwater systems, change dramatically in the presence of permafrost relative to unfrozen conditions. However, although the vertical groundwater flow decreases significantly in the presence of permafrost, there is still an exchange of water between the unfrozen groundwater system below the permafrost and the shallow groundwater in the active layer, via taliks. ‘Through taliks’ tend to prevail in areas that constitute groundwater discharge zones under unfrozen conditions, which then mostly shift to net recharge zones (through taliks with net downward flow) under permafrost conditions.

  • 3.
    Destouni, Georgia
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Asokan, Shilpa M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Augustsson, Anna
    Balfors, Berit
    Bring, Arvid
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Jaramillo, Fernando
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Jarsjö, Jerker
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Johansson, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Juston, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Levi, Lea
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. The Royal Institute of Technology, Sweden; University of Split, Croatia.
    Olofsson, Bo
    Prieto, Carmen
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Quin, Andrew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Åström, Mats
    Cvetkovic, Vladimir
    Needs and means to advance science, policy and management understanding of the freshwater system – A synthesis report2015Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Fragmented and inconsistent understanding of the freshwater system limits our ability to achieve water security and sustainability under the human-driven changes occurring in the Anthropocene. To advance system-level understanding of freshwater, gaps and inconsistencies in knowledge, data, representations and links of processes and subsystems need to be identified and bridged under consideration of the freshwater system as a continuous whole. 

    Based on such identification, a freshwater system conceptualization is developed in this report, which emphasizes four essential, yet often neglected system aspects:

    i) Distinction of coastal divergent catchments.

    ii) Four main zones (surface, subsurface, coastal, observation) of different types of freshwater change.

    iii) Water pathways as system-coupling agents that link and partition water change among the four change zones.

    iv) Direct interactions with the anthroposphere as integral system pathways across the change zones.

    We explain and exemplify some key implications of these aspects, identifying in the process also distinct patterns of human-driven changes in large-scale water fluxes and nutrient loads.

    The present conceptualization provides a basis for common inter- and trans-disciplinary understanding and systematic characterization of the freshwater system function and its changes, and of approaches to their modeling and monitoring. This can be viewed and used as a unifying checklist that can advance science, policy and management of freshwater and related environmental changes across various scales and world regions.

  • 4. Doyle, Samuel H.
    et al.
    Hubbard, Alun
    van de Wal, Roderik S. W.
    Box, Jason E.
    van As, Dirk
    Scharrer, Kilian
    Meierbachtol, Toby W.
    Smeets, Paul C. J. P.
    Harper, Joel T.
    Johansson, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK). Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Mottram, Ruth H.
    Mikkelsen, Andreas B.
    Wilhelms, Frank
    Patton, Henry
    Christoffersen, Poul
    Hubbard, Bryn
    Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall2015Ingår i: Nature Geoscience, ISSN 1752-0894, E-ISSN 1752-0908, Vol. 8, nr 8, s. 647-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior. We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern and western Greenland during this time, and we observe a corresponding ice-flow response at all land- and marine-terminating glaciers in these regions for which data are available. Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change.

  • 5.
    Johansson, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    The influence of climate and permafrost on catchment hydrology2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The cycling of water in the landscape is influenced by climate change on different time scales and in different directions regarding warming or cooling trends. Along with a changing climate, also the landscape and subsurface conditions, such as permafrost extent, may change in a long-term perspective. Permafrost and hydrology are intimately connected but the interactions between them are poorly understood, and the hydrological response to climate change is complex. The first part of this thesis investigates the effects of different drivers of future changes in hydrological flow and water storage components in the present day temperate Forsmark catchment in Sweden. The role of taliks and their influence on the exchange of deep and shallow groundwater in permafrost environments are also studied. This is done by a simulation sequence where the site is exposed to the landscape, climate and permafrost changes expected from site-specific numerical modeling. In the second part of this thesis, present day periglacial hydrological processes are studied in the Two Boat Lake catchment in western Greenland by field and model investigations of the site. The presence of a through talik below the Two Boat Lake, and data from a deep bedrock borehole into the talik, enable studies of the hydrological interactions between the lake and the talik. The spatial and temporal variability of the different water balance components of the catchment are quantified and the interactions between the surface water and the supra- and sub-permafrost groundwater are analyzed.

    The results show that the investigated changes in climate and permafrost influence hydrology more than the investigated landscape changes. Under permafrost conditions, the general direction of the exchange between deep and shallow groundwater may change relative to unfrozen conditions. The simulation studies of Forsmark show that the relative topography between taliks governs the recharging and discharging conditions, which is consistent with results from Two Boat Lake. The lake is located at high altitude relative to other taliks and hydraulic measurements indicate recharging conditions. The talik recharge is small compared to other water balance components and does not influence the lake level, which instead is found to be controlled by evapotranspiration and water inflow from the active layer. This is concluded from numerical simulations that take into account and combine evapotranspiration with other surface and subsurface hydrological processes. This thesis highlights the need to integrate surface and subsurface process modelling in order to quantitatively understand and represent the dynamics and complexity of hydrological interactions in periglacial catchments.

  • 6.
    Johansson, Emma
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Berglund, S.
    Lindborg, Tobias
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish University of Agricultural Science, Sweden.
    Petrone, J.
    van As, D.
    Gustafsson, L.-G.
    Näslund, Jens-Ove
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Laudon, H.
    Hydrological and meteorological investigations in a periglacial lake catchment near Kangerlussuaq, west Greenland - presentation of a new multi-parameter data set2015Ingår i: Earth System Science Data, ISSN 1866-3508, E-ISSN 1866-3516, Vol. 7, nr 1, s. 93-108Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Few hydrological studies have been conducted in Greenland, other than on glacial hydrology associated with the ice sheet. Understanding permafrost hydrology and hydroclimatic change and variability, however, provides key information for understanding climate change effects and feedbacks in the Arctic landscape. This paper presents a new, extensive, and detailed hydrological and meteorological open access data set, with high temporal resolution from a 1.56 km(2) permafrost catchment, with a lake underlain by a through-talik close to the ice sheet in the Kangerlussuaq region, western Greenland. The paper describes the hydrological site investigations and utilized equipment, as well as the data collection and processing. The investigations were performed between 2010 and 2013. The high spatial resolution, within the investigated area, of the data set makes it highly suitable for various detailed hydrological and ecological studies on catchment scale. The data set is available for all users via the PANGAEA database, http://doi.pangaea.de/10.1594/PANGAEA.836178.

  • 7.
    Johansson, Emma
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Gustafsson, Lars-Göran
    Berglund, Sten
    Lindborg, Tobias
    Selroos, Jan-Olof
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Claesson Liljedahl, Lillemor
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Data evaluation and numerical modeling of hydrological interactions between active layer, lake and talik in a permafrost catchment, Western Greenland2015Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 527, s. 688-703Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigates annual water balance conditions and their spatiotemporal variability under a wide variety of atmospheric driving conditions in the periglacial permafrost catchment of Two Boat Lake in Western Greenland. The study uses and combines a comprehensive hydrological multi-parameter dataset measured at the site with site conceptualization and numerical model development, application and testing. The model result reproduces measured lake and groundwater levels, as well as observations made by time-lapse cameras. The results highlights the importance of numerical modeling that takes into account and combines evapotranspiration with other surface and subsurface hydrological processes at various depths, in order to quantitatively understand and represent the dynamics and complexity of the interactions between meteorology, active layer hydrology, lakes, and unfrozen groundwater below permafrost in periglacial catchments. Regarding these interactions, the water flow between the studied lake and a through talik within and beneath it is found to be small compared to other water balance components. The modeling results show that recharge and discharge conditions in the talik can shift in time, while the lake and active layer conditions in the studied catchment are independent of catchment-external landscape features, such as the unfrozen groundwater system below the permafrost and the nearby continental-scale ice sheet.

  • 8. Petrone, Johannes
    et al.
    Sohlenius, Gustav
    Johansson, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Company, Sweden.
    Lindborg, Tobias
    Näslund, Jens-Ove
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Swedish Nuclear Fuel and Waste Management Company, Sweden.
    Strömgren, Mårten
    Brydsten, Lars
    Using ground-penetrating radar, topography and classification of vegetation to model the sediment and active layer thickness in a periglacial lake catchment, western Greenland2016Ingår i: Earth System Science Data, ISSN 1866-3508, E-ISSN 1866-3516, Vol. 8, nr 2, s. 663-677Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The geometries of a catchment constitute the basis for distributed physically based numerical modeling of different geoscientific disciplines. In this paper results from ground-penetrating radar (GPR) measurements, in terms of a 3-D model of total sediment thickness and active layer thickness in a periglacial catchment in western Greenland, are presented. Using the topography, the thickness and distribution of sediments are calculated. Vegetation classification and GPR measurements are used to scale active layer thickness from local measurements to catchment-scale models. Annual maximum active layer thickness varies from 0.3m in wetlands to 2.0m in barren areas and areas of exposed bedrock. Maximum sediment thickness is estimated to be 12.3m in the major valleys of the catchment. A method to correlate surface vegetation with active layer thickness is also presented. By using relatively simple methods, such as probing and vegetation classification, it is possible to upscale local point measurements to catchment-scale models, in areas where the upper subsurface is relatively homogeneous. The resulting spatial model of active layer thickness can be used in combination with the sediment model as a geometrical input to further studies of subsurface mass transport and hydrological flow paths in the periglacial catchment through numerical modeling. The data set is available for all users via the PANGAEA database, doi:10.1594/PANGAEA.845258.

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