BG Biogeosciences BG Biogeosciences 1726-4189 Copernicus Publications Göttingen, Germany 10.5194/bg-10-8109-2013 Climate change impacts on sea–air fluxes of CO<sub>2</sub> in three Arctic seas: a sensitivity study using Earth observation Land P. E. https://orcid.org/0000-0001-7518-8683 1 Shutler J. D. 1 Cowling R. D. 2 Woolf D. K. https://orcid.org/0000-0003-4469-553X 2 Walker P. 1 Findlay H. S. 1 Upstill-Goddard R. C. 3 Donlon C. J. 4 Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK International Centre for Island Technology, Heriot-Watt University, Stromness, Orkney, KW16 3AW, UK School of Marine Science and Technology, Ridley Building, Newcastle University, NE1 7RU, UK European Space Agency, ESTEC/EOP-SME, Keplerlaan 1, 2201 AZ, Noordwijk, the Netherlands 11 12 2013 10 12 8109 8128 Copyright: © 2013 P. E. Land et al. 2013 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://bg.copernicus.org/articles/10/8109/2013/bg-10-8109-2013.html The full text article is available as a PDF file from https://bg.copernicus.org/articles/10/8109/2013/bg-10-8109-2013.pdf

We applied coincident Earth observation data collected during 2008 and 2009 from multiple sensors (RA2, AATSR and MERIS, mounted on the European Space Agency satellite Envisat) to characterise environmental conditions and integrated sea–air fluxes of CO<sub>2</sub> in three Arctic seas (Greenland, Barents, Kara). We assessed net CO<sub>2</sub> sink sensitivity due to changes in temperature, salinity and sea ice duration arising from future climate scenarios. During the study period the Greenland and Barents seas were net sinks for atmospheric CO<sub>2</sub>, with integrated sea–air fluxes of −36 ± 14 and −11 ± 5 Tg C yr<sup>−1</sup>, respectively, and the Kara Sea was a weak net CO<sub>2</sub> source with an integrated sea–air flux of +2.2 ± 1.4 Tg C yr<sup>−1</sup>. The combined integrated CO<sub>2</sub> sea–air flux from all three was −45 ± 18 Tg C yr<sup>−1</sup>. In a sensitivity analysis we varied temperature, salinity and sea ice duration. Variations in temperature and salinity led to modification of the transfer velocity, solubility and partial pressure of CO<sub>2</sub> taking into account the resultant variations in alkalinity and dissolved organic carbon (DOC). Our results showed that warming had a strong positive effect on the annual integrated sea–air flux of CO<sub>2</sub> (i.e. reducing the sink), freshening had a strong negative effect and reduced sea ice duration had a small but measurable positive effect. In the climate change scenario examined, the effects of warming in just over a decade of climate change up to 2020 outweighed the combined effects of freshening and reduced sea ice duration. Collectively these effects gave an integrated sea–air flux change of +4.0 Tg C in the Greenland Sea, +6.0 Tg C in the Barents Sea and +1.7 Tg C in the Kara Sea, reducing the Greenland and Barents sinks by 11% and 53%, respectively, and increasing the weak Kara Sea source by 81%. Overall, the regional integrated flux changed by +11.7 Tg C, which is a 26% reduction in the regional sink. In terms of CO<sub>2</sub> sink strength, we conclude that the Barents Sea is the most susceptible of the three regions to the climate changes examined. Our results imply that the region will cease to be a net CO<sub>2</sub> sink in the 2050s.

 References ACIA: Arctic Climate Impact Assessment, Cambridge University Press, 1042 pp., 2005. Anderson, L. G., Olsson, K., and Chierici, M.: A carbon budget for the Arctic Ocean, Global Biogeochem. Cy., 12, 455–465, 1998a. Anderson, L. G., Olsson, K., Jones, E. P., Chierici, M., and Fransson, A.: Anthropogenic carbon dioxide in the Arctic Ocean: Inventory and sinks, J. Geophys. Res., 103, 27707–27727, 1998b. Arrigo, K. R., van Dijken, G., and Pabi, S.: Impact of a shrinking Arctic ice cover on marine primary production, Geophys. Res. Lett., 35, L19603, <a href="http://dx.doi.org/10.1029/2008GL035028">https://doi.org/10.1029/2008GL035028</a>, 2008. Arrigo, K. R., Pabi, S., van Dijken, G. L., and Maslowski, W.: Air-sea flux of CO<sub>2</sub> in the Arctic Ocean, 1998–2003, J. Geophys. Res., 115, G04024, <a href="http://dx.doi.org/10.1029/2009JG001224">https://doi.org/10.1029/2009JG001224</a>, 2010. Bates, N. R. and Mathis, J. T.: The Arctic Ocean marine carbon cycle: evaluation of air-sea CO<sub>2</sub> exchanges, ocean acidification impacts and potential feedbacks, Biogeosciences, 6, 2433–2459, <a href="http://dx.doi.org/10.5194/bg-6-2433-2009">https://doi.org/10.5194/bg-6-2433-2009</a>, 2009. BEAM: ESA Earth observation toolbox and development platform, version 4.8: <a href="http://www.brockmann-consult.de/cms/web/beam">http://www.brockmann-consult.de/cms/web/beam</a>, 2010. Birks, A.: AATSR products handbook, Issue 2.2, ESA Publications Division, 2007. Bock, E. J., Hara, T., Frew, N. M., and McGillis, W. R.: Relationship between air sea gas transfer and short wind waves, J. Geophys. Res., 104, 25821–25831, 1999. Boutin, J., Etcheto, J., Merlivat, L., and Rangama, Y.: Influence of gas exchange coefficient parameterisation on seasonal and regional variability of CO<sub>2</sub> air-sea fluxes, Geophys. Res. Lett., 29, 1182, <a href="http://dx.doi.org/10.1029/2001GL013872">https://doi.org/10.1029/2001GL013872</a>, 2002. Cai, W. J.: Coastal ocean carbon paradox: CO<sub>2</sub> sinks or sites of terrestrial carbon incineration, Annu. Rev. Mar. Sci., 3, 123–145, 2011. Cooper, L. W., Benner, R., McClelland, J. W., Peterson, B. J., Holmes, R. M., Raymond, P. A., Hansell, D. A., Grebmeier, J. M., and Codispoti, L. A.: Linkages among runoff, dissolved organic carbon, and the stable oxygen isotope composition of seawater and other water mass indicators in the Arctic Ocean, J. Geophys. Res., 110, G02013, <a href="http://dx.doi.org/10.1029/2005JG000031">https://doi.org/10.1029/2005JG000031</a>, 2005. Dai, A., Qian, T., Trenberth, K. E., and Milliman, J. D.: Changes in continental freshwater discharge from 1948 to 2004, J. Climate, 22, 2773–2792, 2009. Denman, K. L., Brasseur, G., Chidthaisong, A., Ciais, P., Cox, P. M., Dickinson, R. E., Hauglustaine, D., Heinze, C., Holland, E., Jacob, D., Lohmann, U., Ramachandran, S., da Silva Dias, P. L., Wofsy, S., and Zhang, X.: Couplings between changes in the climate system and biogeochemistry., in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K., Tignor, M., and Miller, H., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007. Donlon, C., Robinson, I., Casey, K. S., Vazquez-Cuervo, J., Armstrong, E., Arino, O., Gentemann, C., May, D., LeBorgne, P., and Piollé, J.: The global ocean data assimilation experiment high-resolution sea surface temperature pilot project, B. Am. Meteorol. Soc., 88, 1197–1213, 2007. Donlon, C. J., Martin, M., Stark, J., Roberts-Jones, J., Fiedler, E., and Wimmer, W.: The Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) system, Remote Sens. Environ., 116, 140–158, <a href="http://dx.doi.org/10.1016/j.rse.2010.10.017">https://doi.org/10.1016/j.rse.2010.10.017</a>, 2011. Edwards, T., Browning, R., Delderfield, J., Lee, D. J., and Lidiard, K. A.: The along track scanning radiometer-Measurement of sea-surface temperature from ERS-1, J. Brit. Inter. Soc., 43, 160–180, 1990. Else, B. G. T., Papakyriakou, T. N., Granskog, M. A., and Yackel, J. J.: Observations of sea surface <i>f</i>CO<sub>2</sub> distributions and estimated air-sea CO<sub>2</sub> fluxes in the Hudson Bay region (Canada) during the open water season, J. Geophys. Res., 113, C08026, <a href="http://dx.doi.org/10.1029/2005JG000031">https://doi.org/10.1029/2005JG000031</a>, 2008. Else, B. G. T., Papakyriakou, T. N., Galley, R. J., Drennan, W. M., Miller, L. A., and Thomas, H.: Wintertime CO<sub>2</sub> fluxes in an Arctic polynya using eddy covariance: Evidence for enhanced air-sea gas transfer during ice formation, J. Geophys. Res.-Oceans (1978–2012), 116, C00G03, <a href="http://dx.doi.org/10.1029/2010JC006760">https://doi.org/10.1029/2010JC006760</a>, 2011. Fangohr, S. and Woolf, D. K.: Application of new parameterizations of gas transfer velocity and their impact on regional and global marine CO<sub>2</sub> budgets, J. Mar. Syst., 66, 195–203, 2007. Faugère, Y., Ollivier, A., Zanifé, O. Z., Scharroo, R., Martini, A., Roca, M., and Femenias, P.: An operational correction for the RA2 side A USO anomaly: Methods and performance assessment, ESA Symposium 2007, Montreux, Switzerland, 2007. Fransson, A., Chierici, M., Anderson, L. G., Bussmann, I., Kattner, G., Peter Jones, E., and Swift, J. H.: The importance of shelf processes for the modification of chemical constituents in the waters of the Eurasian Arctic Ocean: implication for carbon fluxes, Cont. Shelf Res., 21, 225–242, 2001. Frew, N. M., Goldman, J. C., Dennett, M. R., and Johnson, A. S.: Impact of phytoplankton-generated surfactants on air-sea gas exchange, J. Geophys. Res., 95, 3337–3352, 1990. Gašparović, B., Kozarac, Z., Saliot, A., \'Cosović, B., and Moebius, D.: Physicochemical characterization of natural and ex-situ reconstructed sea-surface microlayers, J. Colloid Interf. Sci., 208, 191–202, 1998. Goddijn-Murphy, L. M., Woolf, D. K., and Marandino, C.: Space-based retrievals of air-sea gas transfer velocities using altimeters; calibration for dimethyl sulfide, J. Geophys. Res., 117, C08028, <a href="http://dx.doi.org/10.1029/2011JC007535">https://doi.org/10.1029/2011JC007535</a>, 2012. Goldman, J. C., Dennett, M. R., and Frew, N. M.: Surfactant effects on air-sea gas exchange under turbulent conditions, Deep-Sea Res., 35, 1953–1970, 1988. Hansell, D. A., Carlson, C. A., Repeta, D. J., and Schlitzer, R.: Dissolved organic matter in the ocean: A controversy stimulates new insights, Oceanography, 22, 202–211, 2009. Ho, D. T., Law, C. S., Smith, M. J., Schlosser, P., Harvey, M., and Hill, P.: Measurements of air-sea gas exchange at high wind speeds in the Southern Ocean: Implications for global parameterizations, Geophys. Res. Lett., 33, 16611, <a href="http://dx.doi.org/10.1029/2006GL026817">https://doi.org/10.1029/2006GL026817</a>, 2006. Ho, D. T., Wanninkhof, R., Schlosser, P., Ullman, D. S., Hebert, D., and Sullivan, K. F.: Toward a universal relationship between wind speed and gas exchange: Gas transfer velocities measured with 3He/SF6 during the Southern Ocean Gas Exchange Experiment, J. Geophys. Res., 116, C00F04, <a href="http://dx.doi.org/10.1029/2010JC006854">https://doi.org/10.1029/2010JC006854</a>, 2011. International Hydrographic Organization: Limits of oceans and seas, International Hydrographic Organization, 1953. Kaltin, S., Anderson, L. G., Olsson, K., Fransson, A., and Chierici, M.: Uptake of atmospheric carbon dioxide in the Barents Sea, J. Mar. Syst, 38, 31–45, 2002. Kettle, H. and Merchant, C. J.: Systematic errors in global air-sea CO<sub>2</sub> flux caused by temporal averaging of sea-level pressure, Atmos. Chem. Phys., 5, 1459–1466, <a href="http://dx.doi.org/10.5194/acp-5-1459-2005">https://doi.org/10.5194/acp-5-1459-2005</a>, 2005. Kettle, H., Merchant, C. J., Jeffery, C. D., Filipiak, M. J., and Gentemann, C. L.: The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux, Atmos. Chem. Phys., 9, 529–541, <a href="http://dx.doi.org/10.5194/acp-9-529-2009">https://doi.org/10.5194/acp-9-529-2009</a>, 2009. Kwok, R., Cunningham, G. F., Wensnahan, M., Rigor, I., Zwally, H. J., and Yi, D.: Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008, J. Geophys. Res., 114, C07005, <a href="http://dx.doi.org/10.1029/2009JC005312">https://doi.org/10.1029/2009JC005312</a>, 2009. Laruelle, G. G., Dürr, H. H., Slomp, C. P., and Borges, A. V.: Evaluation of sinks and sources of CO<sub>2</sub> in the global coastal ocean using a spatially-explicit typology of estuaries and continental shelves, Geophys. Res. Lett., 37, L15607, <a href="http://dx.doi.org/10.1029/2010GL043691">https://doi.org/10.1029/2010GL043691</a>, 2011. Letscher, R. T., Hansell, D. A., and Kadko, D.: Rapid removal of terrigenous dissolved organic carbon over the Eurasian shelves of the Arctic Ocean, Mar. Chem., 123, 78–87, 2011. Lin, I. I., Wen, L. S., Liu, K. K., Tsai, W. T., and Liu, A. K.: Evidence and quantification of the correlation between radar backscatter and ocean colour supported by simultaneously acquired in situ sea truth, Geophys. Res. Lett., 29, 102–101, 2002. Liss, P. S. and Duce, R. A.: The sea surface and global change, Cambridge Univ. Pr., 2005. Liu, A. K., Wu, S. Y., Tseng, W. Y., and Pichel, W. G.: Wavelet analysis of SAR images for coastal monitoring, Can. J. Remote Sens., 26, 494–500, 2000. Liu, J., Curry, J. A., and Hu, Y.: Recent Arctic sea ice variability: Connections to the Arctic Oscillation and the ENSO, Geophys. Res. Lett., 31, L09211, <a href="http://dx.doi.org/10.1029/2004GL019858">https://doi.org/10.1029/2004GL019858</a>, 2004. Lobbes, J. M., Fitznar, H. P., and Kattner, G.: Biogeochemical characteristics of dissolved and particulate organic matter in Russian rivers entering the Arctic Ocean, Geochim. Cosmochim. Ac., 64, 2973–2983, 2000. Loose, B., McGillis, W. R., Schlosser, P., Perovich, D., and Takahashi, T.: Effects of freezing, growth, and ice cover on gas transport processes in laboratory seawater experiments, Geophys. Res. Lett., 36, L05603, <a href="http://dx.doi.org/10.1029/2008GL036318">https://doi.org/10.1029/2008GL036318</a>, 2009. Makkaveev, P. N., Stunzhas, P. A., Mel'nikova, Z. G., Khlebopashev, P. V., and Yakubov, S. K.: Hydrochemical characteristics of the waters in the western part of the Kara Sea, Oceanology, 50, 688–697, 2010. McGillis, W. R. and Wanninkhof, R.: Aqueous CO<sub>2</sub> gradients for air–sea flux estimates, Mar. Chem., 98, 100–108, 2006. McGuire, A. D., Wirth, C., Apps, M., Beringer, J., Clein, J., Epstein, H., Kicklighter, D. W., Bhatti, J., Chapin Iii, F. S., and Groot, B.: Environmental variation, vegetation distribution, carbon dynamics and water/energy exchange at high latitudes, J. Veg. Sci., 13, 301–314, 2002. Nakaoka, S. I., Aoki, S., Nakazawa, T., Hashida, G., Morimoto, S., Yamanouchi, T., and Yoshikawa-Inoue, H.: Temporal and spatial variations of oceanic <i>p</i>CO<sub>2</sub> and air–sea CO<sub>2</sub> flux in the Greenland Sea and the Barents Sea, Tellus B, 58, 148–161, 2006. Nightingale, P. D., Malin, G., Law, C. S., Watson, A. J., Liss, P. S., Liddicoat, M. I., Boutin, J., and Upstill-Goddard, R. C.: In situ evaluation of air-sea gas exchange parameterizations using novel conservative and volatile tracers, Global Biogeochem. Cy., 14, 373–387, 2000. O'Carroll, A. G., Eyre, J. R., and Saunders, R. W.: Three-way error analysis between AATSR, AMSR-E, and in situ sea surface temperature observations, J. Atmos. Ocean. Tech., 25, 1197–1207, 2008. Omar, A. M., Johannessen, T., Olsen, A., Kaltin, S., and Rey, F.: Seasonal and interannual variability of the air-sea CO<sub>2</sub> flux in the Atlantic sector of the Barents Sea, Mar. Chem., 104, 203–213, 2007. Opsahl, S., Benner, R., and Amon, R. M. W.: Major flux of terrigenous dissolved organic matter through the Arctic Ocean, Limnol. Oceanogr., 44, 2017–2023, 1999. Pabi, S., van Dijken, G. L., and Arrigo, K. R.: Primary production in the Arctic Ocean, 1998–2006, J. Geophys. Res., 113, C08005, <a href="http://dx.doi.org/10.1029/2007JC004578">https://doi.org/10.1029/2007JC004578</a>, 2008. Polyakov, I. V., Timokhov, L. A., Alexeev, V. A., Bacon, S., Dmitrenko, I. A., Fortier, L., Frolov, I. E., Gascard, J. C., Hansen, E., and Ivanov, V. V.: Arctic Ocean warming contributes to reduced polar ice cap, J. Phys. Oceanogr., 40, 2743–2756, 2010. Purkey, S. G. and Johnson, G. C.: Warming of global abyssal and deep Southern Ocean waters between the 1990s and 2000s: contributions to global heat and sea level rise budgets, J. Climate, 23, 6336–6351, 2010. Queffeulou, P., Benramy, A., and Croize-Fillon, D.: Analysis of seasonal wave height anomalies from satellite data over the global oceans, ESA Living Planet Symposium, 2010. Raymond, P. A., McClelland, J. W., Holmes, R. M., Zhulidov, A. V., Mull, K., Peterson, B. J., Striegl, R. G., Aiken, G. R., and Gurtovaya, T. Y.: Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers, Global Biogeochem. Cy., 21, GB4011, <a href="http://dx.doi.org/10.1029/2007GB002934">https://doi.org/10.1029/2007GB002934</a>, 2007. Rosmorduc, V., Benveniste, J., Lauret, O., Maheu, C., Milagro, M., and Picot, N.: Radar Altimetry Tutorial: <a href="http://www.altimetry.info">http://www.altimetry.info</a> last access: September 2009. Rysgaard, S., Glud, R. N., Sejr, M. K., Bendtsen, J., and Christensen, P. B.: Inorganic carbon transport during sea ice growth and decay: A carbon pump in polar seas, J. Geophys. Res., 112, C03016, <a href="http://dx.doi.org/10.1029/2006JC003572">https://doi.org/10.1029/2006JC003572</a>, 2007. Salter, M. E., Upstill-Goddard, R. C., Nightingale, P. D., Archer, S. D., Blomquist, B., Ho, D. T., Huebert, B., Schlosser, P., and Yang, M.: Impact of an artificial surfactant release on air-sea gas fluxes during Deep Ocean Gas Exchange Experiment II, J. Geophys. Res., 116, C11016, <a href="http://dx.doi.org/10.1029/2011JC007023">https://doi.org/10.1029/2011JC007023</a>, 2011. Sarmiento, J. L. and Gruber, N.: Ocean biogeochemical dynamics, Cambridge Univ Press, 2006. Smyth, T. J., Tilstone, G. H., and Groom, S. B.: Integration of radiative transfer into satellite models of ocean primary production, J. Geophys. Res., 110, C10014, <a href="http://dx.doi.org/10.1029/2004JC002784">https://doi.org/10.1029/2004JC002784</a>, 2005. Stark, J. D., Donlon, C., O'Carroll, A., and Corlett, G.: Determination of AATSR biases using the OSTIA SST analysis system and a matchup database, J. Atmos. Ocean. Tech., 25, 1208–1217, 2008. Stein, R. and MacDonald, R. W.: Organic carbon budget: Arctic ocean vs Global Ocean, in: The organic carbon cycle in the Arctic Ocean, Springer Verlag, Berlin, 315–322, 2004. Stroeve, J., Serreze, M., Drobot, S., Gearheard, S., Holland, M., Maslanik, J., Meier, W., and Scambos, T.: Arctic sea ice extent plummets in 2007, Eos, 89, 13–14, 2008. Takahashi, T., Sutherland, S. C., Wanninkhof, R., Sweeney, C., Feely, R. A., Chipman, D. W., Hales, B., Friederich, G., Chavez, F., Sabine, C., Watson, A., Bakker, D. C. E., Schuster, U., Metzl, N., Yoshikawa-Inoue, H., Ishii, M., Midorikawa, T., Nojiri, Y., Körtzinger, A., Steinhoff, T., Hoppema, M., Olafsson, J., Arnarson, T. S., Tilbrook, B., Johannessen, T., Olsen, A., Bellerby, R., Wong, C. S., Delille, B., Bates, N. R., and de Baar, H. J. W.: Climatological mean and decadal change in surface ocean <i>p</i>CO<sub>2</sub>, and net sea–air CO<sub>2</sub> flux over the global oceans, Deep-Sea Res. Pt II, 56, 554–577, <a href="http://dx.doi.org/10.1016/j.dsr2.2008.12.009">https://doi.org/10.1016/j.dsr2.2008.12.009</a>, 2009. Tsai, W. and Liu, K. K.: An assessment of the effect of sea surface surfactant on global atmosphere-ocean CO<sub>2</sub> flux, J. Geophys. Res., 108, 3127, <a href="http://dx.doi.org/10.1029/2000JC000740">https://doi.org/10.1029/2000JC000740</a>, 2003. VLIZ: IHO Sea Areas: <a href="http://www.vliz.be/vmdcdata/vlimar/downloads.php">http://www.vliz.be/vmdcdata/vlimar/downloads.php</a>, (last access: April), 2010. Wang, M. and Overland, J. E.: A sea ice free summer Arctic within 30 years, Geophys. Res. Lett., 36, L07502, <a href="http://dx.doi.org/10.1029/2009GL037820">https://doi.org/10.1029/2009GL037820</a>, 2009. Wanninkhof, R.: Relationship between wind speed and gas exchange, J. Geophys. Res., 97, 7373–7382, 1992. Weiss, R. F.: Carbon dioxide in water and seawater: the solubility of a non-ideal gas, Mar. Chem., 2, 203–215, 1974. Weiss, R. F. and Price, B. A.: Nitrous oxide solubility in water and seawater, Mar. Chem., 8, 347–359, 1980. Wolter, K.: Multivariate ENSO Index (MEI): <a href="http://www.esrl.noaa.gov/psd/enso/mei/">http://www.esrl.noaa.gov/psd/enso/mei/</a>, (last access:23 February 2012), 2012. Wolter, K. and Timlin, M. S.: Measuring the strength of ENSO events: How does 1997/98 rank?, Weather, 53, 315–323, 1998. Woolf, D. K.: Parameterization of gas transfer velocities and sea-state-dependent wave breaking, Tellus B, 57, 87–94, 2005. Woolf, D. K., Leifer, I. S., Nightingale, P. D., Rhee, T. S., Bowyer, P., Caulliez, G., De Leeuw, G., Larsen, S. E., Liddicoat, M., and Baker, J.: Modelling of bubble-mediated gas transfer: Fundamental principles and a laboratory test, J. Mar. Syst, 66, 71–91, 2007. Zhang, T., Frauenfeld, O. W., Serreze, M. C., Etringer, A., Oelke, C., McCreight, J., Barry, R. G., Gilichinsky, D., Yang, D., and Ye, H.: Spatial and temporal variability in active layer thickness over the Russian Arctic drainage basin, J. Geophys. Res., 110, D16101, <a href="http://dx.doi.org/10.1029/2004JD005642">https://doi.org/10.1029/2004JD005642</a>, 2005. Žutić, V., \'Cosović, B., Marcenko, E., Bihari, N., and Krsinic, F.: Surfactant production by marine phytoplankton, Mar. Chem., 10, 505–520, 1981.