Change search
Refine search result
1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Kratzer, Susanne
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kyryliuk, Dmytro
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Inorganic Suspended Matter as an indicator of terrestrial influence in Baltic Sea coastal areas - algorithm development, validation and ecological relevanceManuscript (preprint) (Other academic)
  • 2.
    Kratzer, Susanne
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kyryliuk, Dmytro
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Brockmann, Carsten
    Inorganic suspended matter as an indicator of terrestrial influence in Baltic Sea coastal areas - Algorithm development and validation, and ecological relevance2020In: Remote Sensing of Environment, ISSN 0034-4257, E-ISSN 1879-0704, Vol. 237, article id 111609Article in journal (Refereed)
    Abstract [en]

    Suspended particulate matter (SPM) consists both of an organic (OSPM) and an inorganic fraction (ISPM) and the latter can be used as an indicator for coastal influence in the Baltic Sea. The concentration of SPM can be derived from particle scatter if the specific scattering properties of the respective water body are known. In this paper we show that likewise, ISPM can be derived reliably from remotely sensed particle scatter. An empirical algorithm between particle scatter (AC9 data) and ISPM concentration (measured gravimetrically) was derived from in-water measurements. This regional algorithm was then applied to the iop_bpart level 2 product (i.e. the particle scatter measured at 443 nm) derived from OLCI data on Sentinel-A (S3A) using the C2RCC neural network and validated against an independent data set. The standard error of the derived OLCI match-up data was 10%, and was thus within the goal of the mission requirements of Sentinel-3. The generated S3 composite images from spring and autumn 2018 show that in the Baltic Sea most of the ISPM falls out rather close to the shore, whereas only a very small proportion of ISPM is carried further off-shore. This is also supported by in situ ISPM transects measured in the coastal zone. The ISPM images clearly highlight the areas that are most strongly influenced by terrestrial matter. Differences between the NE Baltic and the SE Baltic proper can be explained by the difference in hydrology and coastal influence as well as bathymetry and wind-wave stirring. The method is of interest for coastal zone management and for assessing the effect of seasonal changes in terrestrial run-off and wind-driven resuspension of sediments. It can also be used to evaluate the effect of climate change which has led to an increase of extreme storm and flooding events that are usually accompanied by increased erosion and run-off from land. Last but not least, turbidity caused by particles influences the light conditions in inner coastal areas and bays, which has a profound effect on pelagic productivity, the maximum growth of macroalgae as well as fish behaviour.

  • 3.
    Kratzer, Susanne
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kyryliuk, Dmytro
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Edman, Moa
    Philipson, Petra
    Lyon, Steve W.
    Stockholm University, Faculty of Science, Department of Physical Geography. Ohio State University, USA.
    Synergy of Satellite, In Situ and Modelled Data for Addressing the Scarcity of Water Quality Information for Eutrophication Assessment and Monitoring of Swedish Coastal Waters2019In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 11, no 17Article in journal (Refereed)
    Abstract [en]

    Monthly CHL-a and Secchi Depth (SD) data derived from the full mission data of the Medium Resolution Imaging Spectrometer (MERIS; 2002-2012) were analysed along a horizontal transect from the inner Braviken bay and out into the open sea. The CHL-a values were calibrated using an algorithm derived from Swedish lakes. Then, calibrated Chl-a and Secchi Depth (SD) estimates were extracted from MERIS data along the transect and compared to conventional monitoring data as well as to data from the Swedish Coastal zone Model (SCM), providing physico-biogeochemical parameters such as temperature, nutrients, Chlorophyll-a (CHL-a) and Secchi depth (SD). A high negative correlation was observed between satellite-derived CHL-a and SD (rho = -0.91), similar to the in situ relationship established for several coastal gradients in the Baltic proper. We also demonstrate that the validated MERIS-based estimates and data from the SCM showed strong correlations for the variables CHL-a, SD and total nitrogen (TOTN), which improved significantly when analysed on a monthly basis across basins. The relationship between satellite-derived CHL-a and modelled TOTN was also evaluated on a monthly basis using least-square linear regression models. The predictive power of the models was strong for the period May-November (R-2: 0.58-0.87), and the regression algorithm for summer was almost identical to the algorithm generated from in situ data in Himmerfjarden bay. The strong correlation between SD and modelled TOTN confirms that SD is a robust and reliable indicator to evaluate changes in eutrophication in the Baltic proper which can be assessed using remote sensing data. Amongst all three assessed methods, only MERIS CHL-a was able to correctly depict the pattern of phytoplankton phenology that is typical for the Baltic proper. The approach of combining satellite data and physio-biogeochemical models could serve as a powerful tool and value-adding complement to the scarcely available in situ data from national monitoring programs. In particular, satellite data will help to reduce uncertainties in long-term monitoring data due to its improved measurement frequency.

  • 4.
    Kyryliuk, Dmytro
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Baltic Sea from Space: The use of ocean colour data to improve our understanding of ecological drivers across the Baltic Sea basin – algorithm development, validation and ecological applications2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Coastal areas are the most densely populated areas in the world and thus are under immense anthropogenic pressure. To ensure their function and ecological role, coastal areas require continuous monitoring and management. The rapidly emerging field of satellite remote sensing provides a unique opportunity to monitor both land and oceans from Space. This thesis explores recent developments in ocean colour remote sensing, tests several image processing algorithms, evaluates and maps water quality indicators – both on local and Baltic Sea-wide scale – as well as provides essential monitoring data to complement already existing ship-based monitoring and modelling techniques. The overall aim of the thesis is to broaden our understanding and applicability of ocean colour remote sensing for improved modelling and management of the Baltic Sea and its coastal areas.

    The thesis deals with four independent research topics. In paper I the spatial distribution of Total Suspended Matter (TSM) during the summer season is evaluated using the European Space Agency’s (ESA) MEdium Resolution Imaging Spectrometer (MERIS). The TSM distribution and concentration is retrieved quantitatively from MERIS data for the HELCOM-defined Baltic Sea sub-basins for the summer seasons 2009, 2010, 2011, and summarized in a 3-year summer composite image. Manuscript II deals with the correspondence between satellite, in situ and modelled data in Bråviken bay, NW Baltic proper, which is optically dominated by Coloured Dissolved Organic Matter (CDOM). Chlorophyll-a (CHL-a) and Secchi depth data are analyzed along a horizontal transects reaching from the inner coastal bay out into the open sea. The study addresses the scarcity of in situ monitoring data in comparison to satellite and modelled data. Further, an empirical relationship is established between modelled total nitrogen and CHL-a derived from satellite, potentially allowing to infer information on the distribution of total nitrogen from satellite data. Paper III evaluates the performance of MERIS’s successor – the Ocean and Land Colour Instrument (OLCI) launched on board Sentinel-3A (S3A) satellite. The water quality products derived from S3A OLCI using the Case-2 Regional CoastColour Processor are evaluated via several dedicated validation campaigns (2016-2018) in the NW Baltic proper. In manuscript IV, the in-water relationship between particle scatter at 440 nm and Inorganic Suspended Particulate Matter (ISPM) is used to develop a novel algorithm to derive ISPM from satellite-derived scatter. This algorithm was applied to OLCI data and tested on an independent dataset. The algorithm allows to map the distribution of ISPM across the Baltic Sea basin and to assess the influence of coastal processes.

    The key outcome of this thesis are reliable water-quality products generated on a Baltic Sea-wide scale, using state-of-the-art Ocean Colour data. Specifically, the thesis highlights the benefits of using remote sensing to improve our understanding of coastal and dynamical processes, as well as Baltic Sea ecology on a wider scale, which simply is not possible by any other scientific means. 

    Download full text (pdf)
    Baltic Sea from Space
    Download (jpg)
    Omslagsframsida
  • 5.
    Kyryliuk, Dmytro
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Edman, Moa
    Philipson, Petra
    Lyon, Steve W.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kratzer, Susanne
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Synergy of satellite, in situ and modeled data for addressing the scarcity of water quality information for eutrophication assessment and monitoring of Swedish coastal watersManuscript (preprint) (Other academic)
  • 6.
    Kyryliuk, Dmytro
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kratzer, Susanne
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Evaluation of Sentinel-3A OLCI products derived using the Case-2 Regional CoastColour Processor over the Baltic SeaManuscript (preprint) (Other academic)
  • 7.
    Kyryliuk, Dmytro
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kratzer, Susanne
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Evaluation of Sentinel-3A OLCI Products Derived Using the Case-2 Regional CoastColour Processor over the Baltic Sea2019In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 16, article id 3609Article in journal (Refereed)
    Abstract [en]

    In this study, the Level-2 products of the Ocean and Land Colour Instrument (OLCI) data on Sentinel-3A are derived using the Case-2 Regional CoastColour (C2RCC) processor for the SentiNel Application Platform (SNAP) whilst adjusting the specific scatter of Total Suspended Matter (TSM) for the Baltic Sea in order to improve TSM retrieval. The remote sensing product kd_z90max (i.e., the depth of the water column from which 90% of the water-leaving irradiance are derived) from C2RCC-SNAP showed a good correlation with in situ Secchi depth (SD). Additionally, a regional in-water algorithm was applied to derive SD from the attenuation coefficient K-d(489) using a local algorithm. Furthermore, a regional in-water relationship between particle scatter and bench turbidity was applied to generate turbidity from the remote sensing product iop_bpart (i.e., the scattering coefficient of marine particles at 443 nm). The spectral shape of the remote sensing reflectance (R-rs) data extracted from match-up stations was evaluated against reflectance data measured in situ by a tethered Attenuation Coefficient Sensor (TACCS) radiometer. The L2 products were evaluated against in situ data from several dedicated validation campaigns (2016-2018) in the NW Baltic proper. All derived L2 in-water products were statistically compared to in situ data and the results were also compared to results for MERIS validation from the literature and the current S3 Level-2 Water (L2W) standard processor from EUMETSAT. The Chl-a product showed a substantial improvement (MNB 21%, RMSE 88%, APD 96%, n = 27) compared to concentrations derived from the Medium Resolution Imaging Spectrometer (MERIS), with a strong underestimation of higher values. TSM performed within an error comparable to MERIS data with a mean normalized bias (MNB) 25%, root-mean square error (RMSE) 73%, average absolute percentage difference (APD) 63% n = 23). Coloured Dissolved Organic Matter (CDOM) absorption retrieval has also improved substantially when using the product iop_adg (i.e., the sum of organic detritus and Gelbstoff absorption at 443 nm) as a proxy (MNB 8%, RMSE 56%, APD 54%, n = 18). The local SD (MNB 6%, RMSE 62%, APD 60%, n = 35) and turbidity (MNB 3%, RMSE 35%, APD 34%, n = 29) algorithms showed very good agreement with in situ data. We recommend the use of the SNAP C2RCC with regionally adjusted TSM-specific scatter for water product retrieval as well as the regional turbidity algorithm for Baltic Sea monitoring. Besides documenting the evaluation of the C2RCC processor, this paper may also act as a handbook on the validation of Ocean Colour data.

  • 8.
    Kyryliuk, Dmytro
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kratzer, Susanne
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Summer Distribution of Total Suspended Matter Across the Baltic Sea2019In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 5, article id 504Article in journal (Refereed)
    Abstract [en]

    There are three optical in-water components that, besides water itself, govern the under-water light field: phytoplankton, total suspended matter (TSM), and colored dissolved organic matter (CDOM). In essence, it is the spectral absorption and scattering properties of each optical component that govern the underwater light field, and also the color of the sea that we can perceive, and that can also be measured remotely from space. The Baltic Sea is optically dominated by CDOM, apart from cyanobacteria blooms that often cover most of the Baltic proper during summer. Remote sensing images of TSM reveal large-and mesoscale features and currents, especially in the Southern Baltic, which are influenced both by atmospheric Rossby waves and the Coriolis force. In coastal waters, the optical properties are strongly influenced by inorganic suspended matter, which may originate from coastal erosion and from run-off from land, streams, and rivers. In this paper, we evaluate the distribution of TSM across the Baltic Sea using remote sensing data and statistically compare the TSM loads in the different Helsinki Commission (HELCOM)-defined basins. The total suspended matter (TSM) loads during summer vary substantially in the different basins, with the south-eastern Baltic overall being most influenced by cyanobacteria blooms. The Gdansk basin and the Gulf of Riga were distinguished both by relatively high TSM loads with high standard deviations, indicating strong fluvial input and/or resuspension of sediments. We also evaluate a coastal TSM transect in Himmerfjärden bay, which is located at the Swedish East coast in the Western Gotland Basin. The effect of wind-wave stirring on the distribution of TSM from source (shore) to sink (open sea) can be assessed using satellite data from European Space Agency’s (ESA) MEdium Resolution Imaging Spectrometer (MERIS) mission (2002–2012) with 300 m resolution. The TSM transect data from areas with low wind exposure and a stable thermocline showed a gradient distribution perpendicular to the coast for summer seasons 2009, 2010, 2011, and a 3-year summer composite, confirming a previous bio-optical study from the Western Gotland basin.

1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf