I have been involved in university teaching since 1989. I have taught in a large variety of subjects spanning from plant physiology over marine biology, ecology of macroalgae and phytoplankton, physical oceanography as well as marine remote sensing.
Recently, I have mostly taught Bio-optical Oceanography and Marine Remote Sensing at Stockholm University and at KTH.
During 2008-2016 I was main coordinator for the Nordic Network for Baltic Sea Remote Sensing and coordinated the PhD training and scientific workshops for the network: Nordic Network Events.
I have also been invited lecturer for the ERASMUS Mundus Masters course on Water and Coastal Managment. I taught at Plymouth University, UK and at the University of the Algarve, Faro (2005-2010).
My total teaching hours amount to 30 ECTS (13 ECTS on basic level, 9 ECTS on Master level and 8 ECTS on PhD level).
I have done more than 10 ECTS in formal university pedagogics training and I have published four book chapters on bio-optics and ocean colour remote sensing. I also contributed to making a film section on 'The colour of the Baltic Sea' in the film: The Science of Ocean Colour, directed by Roland Doerffer (46 min).
Besides that I am national advisor in bio-optics and provide vocational training on bio-optical measurements to the Swedish monitoring groups (SMHI, GU, UU, SU). The training workshops are funded by HaV, the Swedish Agency for Marine and Water Management.
I am Principle Investigator of the Marine Remote Sensing Group (MRSG) at Stockholm Univeristy. Our research focus is on large-scale process studies of aquatic ecosystems, using bio-optical and remote sensing methods. My PhD thesis included a comparative study of the Irish Sea and the Baltic Sea in terms of bio-optical properties and is relevant both for ecological considerations as well as for marine remote sensing.
The strength of ocean colour research is that one uses a range of methods and scales of observations that provide us with a synoptic ‘window’ for the analysis of pelagic ecosystems, and therefore may lead to new understanding of these systems. Remote sensing data provide us with information on physical drivers and productivity in the sea (e.g. attenuation of light, wind, and sea surface temperature) and can help to monitor phytoplankton blooms. It also provides important information to evaluate the on-set of phytoplankton blooms in spring and the development of cyanobacteria blooms in summer, and to assess changes in phenology.
A strong focus in my research is to define the inherent optical properties of the Baltic Sea and to develop regional remote sensing algorithms (fundamental research). I have 20 years of experience in validating satellite data and I am active member of ESA's MERIS and Sentinel-3 validation teams. I am also PI of the NASA AERONET-OC station Pålgrunden. My research has also contibutes towards implementation of marine remote sensing methods in coastal and Baltic Sea management (applied research).
I have hosted several post docs in my group and was the main supervisor of 4 PhD students. Dr. Dmytro Kyryliuk defended his thesis ‘Baltic Sea from Space’ in September 2019. Dr. Elina Kari defended her thesis ‘Light conditions in seasonally ice-covered waters’ in September 2018. Besides this, Dr. Jose Beltrán-Abaunza defended his PhD thesis ‘Remote sensing in optically complex waters’ in Jan 2016, and Dr. Therese Harvey defended her PhD thesis ‘Bio-optics, satellite remote sensing and Baltic Sea ecosystems’ in Oct 2015.
I have close collaborations with Umeå University, Strömbeck Consulting, Brockmann Geomatics Sweden AB as well as JRC, Ispra (Italy), Tartu Observatory, University of Tartu (Estonia), SYKE, Helsinki (Finland), Brockmann Consult GmbH (Germany).
Kratzer, S., & Plowey, M., 2021. Integrating mooring and ship-based data for improved validation of OLCI chlorophyll-a products in the Baltic Sea. International Journal of Applied Earth Observation and Geoinformation, 94, 102212.
Kratzer, S.,Kyryliuk, D. and Brockmann, C., 2020. Inorganic suspended matter as an indicator of terrestrial influence in Baltic Sea coastal areas—Algorithm development and validation, and ecological relevance. Remote Sensing of Environment, 237, 111609.
Kratzer, S.,Kyryliuk, D., Edman, M., Philipson, P. and Lyon, S.W., 2019. Synergy of Satellite, in situ and Modelled Data for Addressing the Scarcity of Water Quality Information for Eutrophication Assessment and Monitoring of Swedish Coastal Waters. Remote Sensing, 11(17), 2051.
Kratzer, S. and Moore, G., 2018. Inherent Optical Properties of the Baltic Sea in Comparison to Other Seas and Oceans. Remote Sensing, 10(3), p.418. Link to the article.
Alikas, K. and Kratzer, S., 2017. Improved retrieval of Secchi depth for optically-complex waters using remote sensing data. Ecological Indicators, 77: 218-227.
Kari, E, Kratzer, S., Beltrán-Abaunza, J, Harvey, ET and Vaičiūtė, D, 2016. Retrieval of suspended particulate matter from turbidity– model development, validation, and application to MERIS data over the Baltic Sea; International Journal of Remote Sensing, 1-21. Link to the article.
Harvey T., Kratzer S., Andersson, A., 2015, Relationships between Coloured Dissolved Organic Matter (CDOM) and Dissolved Organic Carbon (DOC) in different coastal gradients of the Baltic Sea, Ambio 44 (3), 392-401.
Kratzer, S., Harvey, T. and Philipson, P., 2014, The use of ocean colour remote sensing in integrated coastal zone management- a case study from Himmerfjärden, Sweden. Marine Policy 43, 29–39.
Kratzer, K. and Vinterhav, C., 2010, Improvement of MERIS data in Baltic Sea coastal areas by applying the Improved Contrast between Ocean and Land processor (ICOL), Oceanologia, 51(4): 1-26.
Kratzer, S. and Tett, P., 2009, Using bio-optics to investigate the extent of coastal waters a Swedish case study, Hydrobiologia, 629:169-186.
Kratzer, S., Brockmann, C. and Moore G., 2008, Using MERIS full resolution data (300 m spatial resolution) to monitor coastal waters– a case study from Himmerfjärden, a fjord-like bay in the north-western Baltic Sea, Remote Sensing of Environment, 112(5), 2284-2300.
Kratzer, S., Håkansson, B., and Sahlin, C., 2003, Assessing Secchi and photic zone depth in the Baltic Sea from Space, Ambio, 32:8, 577-585.
Kratzer, S., Bowers, D. and Tett, P., 2000, Seasonal changes in colour ratios and optically active constituents in the optical Case-2 waters of the Menai Strait, North Wales, International Journal of Remote Sensing, 21 (11): 2225-2246.