hydrophysicsФундаментальная и прикладная гидрофизикаFundamental and Applied Hydrophysics2073-66732782-5221St. Petersburg Research Center of the Russian Academy of Sciences10.7868/S2073667318030024hydrophysics-738Research ArticleГИДРООПТИКАHYDROOPTICSОтражательные свойства арктического летнего льда в видимом и инфракрасном диапазонахReflective Properties of Summer Arctic Sea Ice in Visible and Near InfraredЗегеЭ. П.ZegeE. P.

г. Минск

Minsk

МалинкаА. В.MalinkaA. V.

г. Минск

Minsk

КацевИ. Л.KatsevI. L.

г. Минск

Minsk

ПрихачА. С.PrikhachA. S.

г. Минск

Minsk

ИстоминаЛ.IstominaL.

Бремен

Bremen

ХейгстерГ.HeygsterG.

Бремен

Bremen

СпринГ.SpreenG.

Бремен

Bremen

Институт физики им Б. И. Степанова НАН БеларусиБеларусьInstitute of Physics, NAS of BelarusBelarusИнститут физики окружающей среды, Бременский УниверситетГерманияInstitute of Environmental Physics, University of BremenGermanyИнститут физики окружающей среды, Бременский УниверситетГермания2Institute of Environmental Physics, University of BremenGermany2018151120221131725Copyright © Зеге Э.П., Малинка А.В., Кацев И.Л., Прихач А.С., Истомина Л., Хейгстер Г., Сприн Г., 20222022Зеге Э.П., Малинка А.В., Кацев И.Л., Прихач А.С., Истомина Л., Хейгстер Г., Сприн Г.Zege E.P., Malinka A.V., Katsev I.L., Prikhach A.S., Istomina L., Heygster G., Spreen G.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://hydrophysics.spbrc.ru/jour/article/view/738

Представлен краткий обзор работ авторов, в которых развита аналитическая теория спектральных оптических характеристик различных типов морского льда как рассеивающей среды (коэффициентов ослабления и поглощения, индикатрисы рассеяния), а также модели отражения ледовым покрытием в Арктике. Лед моделируется как статистически однородная случайная смесь лед-воздух-вода с крупным (по сравнению с длиной волны излучения) масштабом неоднородностей. Параметры смеси (концентрации и размеры неоднородностей) определяются генезисом и положением слоев льда. Во всех случаях масштаб неоднородностей много больше длины волны света. Для определения оптических характеристик различных типов морского льда развиты теории рассеяния света стохастической смесью в приближениях геометрической оптики и Вентцеля—Крамерса—Бриллюэна. Спектральное отражение ледовыми полями описывается в рамках асимптотической теории распространения света в оптически толстых слабопоглощающих слоях. Для описания оптических характеристик тающего (летнего) льда развита модель отражения света прудом талой воды на льду (снежницей). Таким образом определяются все оптические характеристики арктического льда, которые необходимы в качестве входных данных для расчёта переноса излучения. Показано хорошее совпадение полученных результатов с данными измерений, выполненных в ряде арктических экспедиций. Развиты методы атмосферной коррекции спутниковых и полевых данных.

This article presents a brief overview of the recent authors’ works where analytical solutions for the reflection characteristics of summer ice floes with melt ponds in the Visible and near IR have been developed, checked with field experiments and discussed. Sea ice is considered as a statistically homogeneous random mixture of ice, air, and water with a large (in comparison with the light wavelength) scale of inhomogeneities. Within the framework of stereology the inherent scattering characteristics (the attenuation and absorption coefficients, scattering phase functions) of various types of sea ice have been specified analytically. Spectral reflection by ice layers is described within the asymptotic approach of the radiative transfer theory of light propagation in optically thick and comparatively weakly absorbing layers. During melting period the surfaces of ice floes are covered by so called white ice and melt ponds in different proportions. The main factor determining the pond reflection is reflection of its bottom ice. The spectral-angular characteristics of the reflection by both these components (white ice and melt ponds) of Arctic summer ice floes are presented. It is shown that the obtained results are in good agreement with the measurements made in a number of Arctic expeditions, the developed methods of atmospheric correction, which is necessary for processing of both Arctic satellite and field data, being used.

арктический морской ледтаяниеотражение светаоптические характеристики льдарассеяние светаarctic sea icemeltinglight reflectanceice optical propertiesscatteringReferencesGrenfell T. C., Maykut G. A. The optical properties of ice and snow in the Arctic basin // J. Glaciol. 1977. V. 18, N 80. P. 445—463.Grenfell T. C., Maykut G. A. The optical properties of ice and snow in the Arctic basin. J. Glaciol. 1977, 18, 80, 445—463.Perovich D. K. The optical properties of sea ice // US Army Cold Regions Research and Engineering Laboratory (CRREL) Report 96-1, Hanover, NH, USA, 1996. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA310586 (date of access: 24.03.2016).Perovich D. K. The optical properties of sea ice. US Army Cold Regions Research and Engineering Laboratory (CRREL) Report 96-1, Hanover, NH, USA, 1996. URL: www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA310586 (date of access: 24 March 2016).Sea Ice Nomenclature, WMO No. 259, Suppl. No.5, SPA_ETSI_manual_SIM02, 2014. URL: http://www.ioc-unesco.org/index.php?option=com_oe&task=viewDocumentRecord&docID=4438 (date of access: 24.03.2016).Sea Ice Nomenclature, WMO No. 259, Suppl. No.5, SPA_ETSI_manual_SIM02, 2014. URL: http://www.ioc-unesco.org/index.php?option=com_oe&task=viewDocumentRecord&docID=4438 (date of access: 24 March 2016).Назинцев Ю. Л. Тепловой баланс поверхности многолетнего ледяного покрова в Центральной Арктике // Труды ААНИИ.1964. Т. 267. С. 110—126.Nazintsev Y. L. Thermal balance of the surface of the perennial ice cover in the central Arctic. Works of Arctic and Antarctic Scientific Research Institute (Tr. Arkt. Antarkt. Nauchno-Issled. Inst.). 1964, 267, 110—126 (in Russian).Доронин Ю. П. Тепловое взаимодействие атмосферы и гидросферы в Арктике. Л.: Гидрометеоиздат, 1969, 299 с.Doronin Yu. P. Thermal interaction between the atmosphere and the hydrosphere in the Arctic. Leningrad, Gidrometeoizdat, 1969. 244 p. (in Russian).Mobley C. D., Cota G. F., Grenfell T. C., Maffione R. A., Pegau W. S., Perovich D. K. Modeling Light Propagation in Sea Ice // IEEE Transactions On Geoscience And Remote Sensing. 1998. V. 36, N 5. P. 1743—1749.Mobley C. D., Cota G. F., Grenfell T. C., Maffione R. A., Pegau W. S., Perovich D. K. Modeling Light Propagation in Sea Ice. IEEE Transactions On Geoscience And Remote Sensing. 1998, 36, 5, 1743—1749.Light B. Theoretical and observational techniques for estimating light scattering in first-year Arctic sea ice // A. Kokhanovsky (Ed.),Light Scattering Reviews 5. Single Light Scattering and Radiative Transfer. Berlin, Springer, 2010. P. 331—391.Light B. Theoretical and observational techniques for estimating light scattering in first-year Arctic sea ice / A. Kokhanovsky (Ed.), Light Scattering Reviews 5. Single Light Scattering and Radiative Transfer. Berlin, Springer. 2010, 331—391.Nicolaus M., Gerland S., Hudson S.R., Hanson S., Haapala J., Perovich D. K. Seasonality of spectral albedo and transmittance asobserved in the Arctic Transpolar Drift in 2007 // J. Geophys. Res. 2010. V.115, C11011. doi:10.1029/2009JC006074Nicolaus M., Gerland S., Hudson S. R., Hanson S., Haapala J., Perovich D. K. Seasonality of spectral albedo and transmittance as observed in the Arctic Transpolar Drift in 2007. J. Geophys. Res. 2010, 115, C11011, doi:10.1029/2009JC006074.Heygster G., Alexandrov V., Dybkjær G., Girard-Ardhuin F., Hoyningen-Huene W. von, Katsev I. L., Kokhanovsky A., Lavergne T.,Malinka A. V., Melsheimer C., Pedersen L. T., Prikhach A. S., Saldo R., Tonboe R., Wiebe H., Zege E. P. Remote sensing of sea ice:advances during the DAMOCLES project // The Cryosphere. 2012. V. 6. P. 1411—1434. doi:10.5194/tc-6-1411-2012Heygster G., Alexandrov V., Dybkjær G., Girard-Ardhuin F., Hoyningen-Huene W. von, Katsev I. L., Kokhanovsky A., Lavergne T., Malinka A. V., Melsheimer C., Pedersen L. T., Prikhach A. S., Saldo R., Tonboe R., Wiebe H., Zege E. P. Remote sensing of sea ice: advances during the DAMOCLES project. The Cryosphere. 2012, 6, 1411—1434, doi:10.5194/tc-6-1411-2012.Boetius A. et al. Export of Algal Biomass from the Melting Arctic Sea Ice // Science. 2013. V. 339, N 6126. P. 1430—1432. doi:10.1126/science.1231346Boetius A. et al. Export of Algal Biomass from the Melting Arctic Sea Ice. Science. 2013, 339, 6126, 1430—1432, doi:10.1126/science.1231346Polashenski C., Perovich D., Courville Z. The mechanisms of sea ice melt pond formation and evolution // J. Geophys. Res. 2012. V. 117, C01001. doi:10.1029/2011JC007231Polashenski C., Perovich D., Courville Z. The mechanisms of sea ice melt pond formation and evolution. J. Geophys. Res. 2012, 117, C01001, doi:10.1029/2011JC007231Rösel A., Kaleschke L., Birnbaum G. Melt ponds on Arctic sea ice determined from MODIS satellite data using an artificial neural network // The Cryosphere. 2012. V. 6. P. 431—446.Rösel A., Kaleschke L., Birnbaum G. Melt ponds on Arctic sea ice determined from MODIS satellite data using an artificial neural network. The Cryosphere. 2012, 6, 431—446.Istomina L., Heygster G., Huntemann M., Marks H., Melsheimer C., Zege E., Malinka A., Prikhach A., Katsev I. Melt pond fraction and spectral sea ice albedo retrieval from MERIS data — Part 2: Case studies and trends of sea ice albedo and melt ponds in the Arctic for years 2002—2011 // The Cryosphere. 2015. V. 9. P. 1567—1578. doi:10.5194/tc-9-1567-2015Istomina L., Heygster G., Huntemann M., Marks H., Melsheimer C., Zege E., Malinka A., Prikhach A., Katsev I. Melt pond fraction and spectral sea ice albedo retrieval from MERIS data — Part 2: Case studies and trends of sea ice albedo and melt ponds in the Arctic for years 2002–2011. The Cryosphere. 2015, 9, 1567—1578, doi:10.5194/tc-9-1567-2015Maykut G. A., Grenfell T. C., Weeks W. F. On estimating the spatial and temporal variations in the properties of ice in the polar oceans // J. Marine Syst. 1992. V. 3. P. 41—72.Maykut G. A., Grenfell T. C., Weeks W. F. On estimating the spatial and temporal variations in the properties of ice in the polar oceans. J. Marine Syst. 1992, 3, 41—72.Langleben M. P. Albedo of melting sea ice in the southern Beaufort Sea // J. Glaciol. 1971. V. 10. P. 101—104.Langleben M. P. Albedo of melting sea ice in the southern Beaufort Sea. J. Glaciol. 1971, 10, 101—104.Schröder D., Feltham D. L., Flocco D., Tsamados M. September Arctic sea-ice minimum predicted by spring melt-pond fraction // Nature: Climate Change. 2014. V. 4. P. 353—357. doi:10.1038/nclimate2203Schröder D., Feltham D. L., Flocco D., Tsamados M. September Arctic sea-ice minimum predicted by spring melt-pond fraction. Nature: Climate Change. 2014, 4, 353—357, doi:10.1038/nclimate2203Perovich D. K. Light reflection from sea ice during the onset of melt // J. Geophys. Res. 1994. V. 99, N C2. P. 3351—3359.Perovich D. K. Light reflection from sea ice during the onset of melt. J. Geophys. Res. 1994, 99, C2, 3351—3359.Morassutti M. F., Ledrew E. F. Albedo and depth of melt ponds on sea-ice // Int. J. Climatol. 1996. V. 16. P. 817—838.Morassutti M. F., Ledrew E. F. Albedo and depth of melt ponds on sea-ice. Int. J. Climatol. 1996, 16, 817—838.Perovich D. K., Grenfell T. C., Light B., Hobbs P. V. Seasonal evolution of the albedo of multiyear Arctic sea ice // J. Geophys. Res. 2002. V. 107, C108044.Perovich D. K., Grenfell T. C., Light B., Hobbs P. V. Seasonal evolution of the albedo of multiyear Arctic sea ice. J. Geophys. Res. 2002, 107, C108044.Perovich D. K., Grenfell T. C., Light B., Elder B.C., Harbeck J., Polashenski C., Tucker III W. B., Stelmach C. Transpolar observations of the morphological properties of Arctic sea ice // J. Geophys. Res. 2009. V. 114, C00A04. doi:10.1029/2008JC004892.Perovich D. K., Grenfell T. C., Light B., Elder B. C., Harbeck J., Polashenski C., Tucker III W. B., Stelmach C. Transpolar observations of the morphological properties of Arctic sea ice. J. Geophys. Res. 2009, 114, C00A04, doi:10.1029/2008JC004892.Makshtas A. P., Podgorny I. A. Calculation of melt pond albedos on arctic sea ice // Polar Res. 1996. V. 15, N 1. P. 43—52.Makshtas A. P., Podgorny I. A. Calculation of melt pond albedos on arctic sea ice. Polar Res. 1996, 15, 1, 43—52.Malinka A. Light scattering in porous materials: Geometrical optics and stereological approach // J. of Quantit. Spectrosc. & Radiat. Transf. 2014. V. 141. P. 14—23.Malinka A. Light scattering in porous materials: Geometrical optics and stereological approach. J. of Quantit. Spectrosc. & Radiat. Transf. 2014, 141, 14—23.Malinka A. Analytical expressions for characteristics of light scattering by arbitrarily shaped particles in the WKB approximation // J. Opt. Soc. Am. A. 2015. V. 32. P. 1344—1351. doi: 10.1364/JOSAA.32.001344Malinka A. Analytical expressions for characteristics of light scattering by arbitrarily shaped particles in the WKB approximation. J. Opt. Soc. Am. A. 2015, 32, 1344—1351. doi: 10.1364/JOSAA.32.001344.Malinka A., Zege E., Heygster G., Istomina L. Reflective properties of white sea ice and snow // The Cryosphere. 2016. V. 10. P. 2541—2557. doi:10.5194/tc-10-2541-2016Malinka A., Zege E., Heygster G., Istomina L. Reflective properties of white sea ice and snow. The Cryosphere. 2016, 10, 2541— 2557, doi:10.5194/tc-10-2541-2016.Malinka A., Zege E., Istomina L., Heygster G., Spreen G., Perovich D., Polashenski C. Reflective properties of melt ponds on sea ice // The Cryosphere Discuss. 2017. doi:10.5194/tc-2017-150, in review.Malinka A., Zege E., Istomina L., Heygster G., Spreen G., Perovich D., Polashenski C. Reflective properties of melt ponds on sea ice. The Cryosphere Discuss. 2017, doi:10.5194/tc-2017-150, in review.Bricaud A., Morel A., Prieur L. Absorption by dissolved organic matter of the sea (yellow substance) in the UV and visible domains // Limnol. Oceanogr. 1981. V. 26 (1). P. 43—53.Bricaud A., Morel A., Prieur L. Absorption by dissolved organic matter of the sea (yellow substance) in the UV and visible domains. Limnol. Oceanogr. 1981, 26 (1), 43—53.Kopelevich O. V., Lyutsarev S. V., Rodionov V. V. Spectral light absorption by yellow substance in seawater // Oceanology. 1989. V. 29. P. 305—309.Kopelevich O. V., Lyutsarev S. V., Rodionov V. V. Spectral light absorption by yellow substance in seawater. Oceanology. 1989, 29, 305—309.Thomas D. N., Kattner G., Engbrodt R., Gianelli V., Kennedy H., Haas C., Dieckmann G. Dissolved organic matter in Antarctic sea ice // Annals of Glaciology. 2001. V. 33. P. 297—303.Thomas D. N., Kattner G., Engbrodt R., Gianelli V., Kennedy H., Haas C., Dieckmann G. Dissolved organic matter in Antarctic sea ice. Annals of Glaciology. 2001, 33, 297—303.Xue Sh., Wang Ch., Zhang Zh., Song Y., Liu Q. Photodegradation of dissolved organic matter in ice under solar irradiation // Chemosphere. 2016. V. 144. P. 816—826.Xue Sh., Wang Ch., Zhang Zh., Song Y., Liu Q. Photodegradation of dissolved organic matter in ice under solar irradiation. Chemosphere. 2016, 144, 816—826.Rozenberg G. V. Optical properties of thick layers of a homogeneous scattering medium // Smithsonian Institution, Astrophysical Observatory, Astronomical papers translated from the Russian, Iss. 9, ASIN: B0007F925C, 1966. Translated from: Spectroscopy of light scattering media. Academy of Sciences of the BSSR, Minsk, 1963, P. 5—35.Rozenberg G. V. Optical properties of thick layers of a homogeneous scattering medium. Smithsonian Institution, Astrophysical Observatory, Astronomical papers translated from the Russian, ASIN: B0007F925C, 1966, 9. Translated from: Spectroscopy of light scattering media, Academy of Sciences of the BSSR, Minsk, 1963, 5—35.Гермогенова Т. А. Некоторые формулы для решения уравнения переноса в задаче о плоском слое // Спектроскопия светорассеивающих сред (ред. ак. АН БССР Б.И. Степанов). Минск: Издательство Академии Наук БССР, 1963. C. 36—41.Germogenova T. A. Some formulas to solve the transfer equation for a plane layer. Spectroscopy of light scattering media, Academy of Sciences of the BSSR, Minsk, 1963, 36—41 (in Russian).Hulst H. C. van de. Radiative transfer in thick atmospheres with an arbitrary scattering function // Bull. Astron. Inst. Netherlands. 1968. V. 20. P. 77—86.Hulst H. C. van de. Radiative transfer in thick atmospheres with an arbitrary scattering function. Bull. Astron. Inst. Netherlands. 1968, 20, 77—86.Sobolev V. V. Light scattering in planetary atmospheres. Oxford, New York: Pergamon Press, 1975.Sobolev V. V. Light scattering in planetary atmospheres. Oxford, New York, Pergamon Press, 1975.Zege E., Katsev I., Malinka A., Prikhach A., Polonsky I. New algorithm to retrieve the effective snow grain size and pollution amount from satellite data // Ann. Glaciol. 2008. V. 49. P. 139—144.Zege E., Katsev I., Malinka A., Prikhach A., Polonsky I. New algorithm to retrieve the effective snow grain size and pollution amount from satellite data. Ann. Glaciol. 2008, 49, 139—144.Zege E. P., Katsev I. L., Malinka A. V., Prikhach A. S., Heygster G., Wiebe H. Algorithm for retrieval of the effective snow grain size and pollution amount from satellite measurements // Remote Sens. Environ. 2011. V. 115, N 10. P. 2674—2685.Zege E. P., Katsev I. L., Malinka A. V., Prikhach A. S., Heygster G., Wiebe H. Algorithm for retrieval of the effective snow grain size and pollution amount from satellite measurements. Remote Sens. Environ. 2011, 115, 10, 2674—2685.Tynes H., Kattawar G. W., Zege E. P., Katsev I. L., Prikhach A. S., Chaikovskaya L. I. Monte Carlo and multi-componentapproximation methods for vector radiative transfer by use of effective Mueller matrix calculations // Appl. Opt. 2001. V. 40. P. 400—412.Tynes H., Kattawar G. W., Zege E. P., Katsev I. L., Prikhach A. S., Chaikovskaya L. I. Monte Carlo and multi-component approximation methods for vector radiative transfer by use of effective Mueller matrix calculations. Appl. Opt. 2001, 40, 400—412.Zege E., Malinka A., Katsev I., Prikhach A., Heygster G., Istomina L., Birnbaum G., Schwarz P. Algorithm to retrieve the melt pond fraction and the spectral albedo of Arctic summer ice from satellite optical data // Remote Sens. Environ. 2015. V. 163. P. 153—164, doi:10.1016/j.rse.2015.03.012Zege E., Malinka A., Katsev I., Prikhach A., Heygster G., Istomina L., Birnbaum G., Schwarz P. Algorithm to retrieve the melt pond fraction and the spectral albedo of Arctic summer ice from satellite optical data. Remote Sens. Environ. 2015, 163, 153—164, doi:10.1016/j.rse.2015.03.012Istomina L., Nicolaus M., Perovich D. Spectral albedo of sea ice and melt ponds measured during POLARSTERN cruise ARK XXII/3 (IceArc) in 2012. IUP, Universität Bremen, PANGAEA Dataset, 2013. doi:10.1594/PANGAEA.815111Istomina L., Nicolaus M., Perovich D. Spectral albedo of sea ice and melt ponds measured during POLARSTERN cruise ARK XXII/3 (IceArc) in 2012. IUP, Universität Bremen, PANGAEA Dataset, 2013, doi:10.1594/PANGAEA.815111Malinka A. V., Zege E. P., Katsev I. L., Prikhach A. S., Istomina L. Accounting for Atmospheric Effects in the Interpretation of Satellite and Ground-Based Optical Measurements // J. Appl. Spectrosc. 2016. V. 83, N 5. doi:10.1007/s10812-016-0357-3Malinka A. V., Zege E. P., Katsev I. L., Prikhach A. S., Istomina L. Accounting for Atmospheric Effects in the Interpretation of Satellite and Ground-Based Optical Measurements. J. Appl. Spectrosc. 2016, 83, 5, doi:10.1007/s10812-016-0357-3Istomina L., Heygster G., Zege E., Malinka A., Prikhach A., Katsev I. Albedo and meltpond analysis: validation and calibration of the MPD retrieval using sea ice and melt pond albedo spectra measured during Polarstern cruise IceArc2012 / Scientific report no. D4.4 to project SIDARUS (Sea Ice Downstream services for Arctic and Antarctic Users and Stakeholders), grant no. 262922 of the 7th Framework Programme for Research and Development. 2013. URL: http://sidarus.nersc.no/content/public-deliverables (date of access: 27.04.2018).Istomina L., Heygster G., Zege E., Malinka A., Prikhach A., Katsev I. Albedo and meltpond analysis: validation and calibration of the MPD retrieval using sea ice and melt pond albedo spectra measured during Polarstern cruise IceArc2012 / Scientific report no. D4.4 to project SIDARUS (Sea Ice Downstream services for Arctic and Antarctic Users and Stakeholders), grant no. 262922 of the 7th Framework Programme for Research and Development. 2013. URL: http://sidarus.nersc.no/content/public-deliverables (date of access: 27.04.2018).Gavrilo V. P., Gaitskhoki B. Y. The statistics of air inclusions in ice // The Physics of Ice, edited by Bogorodskii V. V., translated from Russian, Isr. Program for Sci. Transl., Jerusalem, 125—128, 1970.Gavrilo V. P., Gaitskhoki B. Y. The statistics of air inclusions in ice. The Physics of Ice. Ed. by Bogorodskii V. V., translated from Russian, Isr. Program for Sci. Transl., Jerusalem, 125—128, 1970.Zege E. P., Ivanov A. P., Katsev I. L. Image transfer through a scattering medium. Heidelberg: Springer—Verlag, 1991.Zege E. P., Ivanov A. P., Katsev I. L. Image transfer through a scattering medium. Heidelberg, Springer-Verlag, 1991.Tomasi C., Vitale V., Lupi A., Carmine C. Di, Campanelli M., Herber A., Treffeisen R., Stone R. S., Andrews E., Sharma S., RadionovV., Hoyningen-Huene W. von, Stebel K., Hansen G. H., Myhre C. L., Wehrli C., Aaltone V., Lihavainen H., Virkkula A., HillamoR., Ström J., Toledano C., Cachorro V. E., Ortiz P., Frutos A. M. de, Blindheim S., Frioud M., Gausa M., Zielinski T., Petelski T., Yamanouchi T. Aerosols in polar regions: A historical overview based on optical depth and in situ observations // J. Geophys. Res. 2007. V. 112, D16205. doi:10.1029/2007JD008432.Tomasi C., Vitale V., Lupi A., Carmine C. Di, Campanelli M., Herber A., Treffeisen R., Stone R. S., Andrews E., Sharma S., Radionov V., Hoyningen-Huene W. von, Stebel K., Hansen G. H., Myhre C. L., Wehrli C., Aaltonen V., Lihavainen H., Virkkula A., Hillamo R., Ström J., Toledano C., Cachorro V. E., Ortiz P., Frutos A. M. de, Blindheim S., Frioud M., Gausa M., Zielinski T., Petelski T., Yamanouchi T. Aerosols in polar regions: A historical overview based on optical depth and in situ observations. J. Geophys. Res. 2007, 112, D16205, doi:10.1029/2007JD008432.

The authors declare that there are no conflicts of interest present.