Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions
The size and shape of snow grains directly impacts the reflection by a snowpack. In this article, different approaches to retrieve the optical-equivalent snow grain size (ropt) or, alternatively, the specific surface area (SSA) using satellite, airborne, and ground-based observations are compared an...
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Online Access: | https://epic.awi.de/id/eprint/55709/ https://epic.awi.de/id/eprint/55709/1/2021_Jaekel-etal_Remotesensing.pdf https://www.mdpi.com/journal/remotesensing https://hdl.handle.net/10013/epic.5688e336-b2f1-4c75-a44f-a3b17052885c https://hdl.handle.net/ |
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ftawi:oai:epic.awi.de:55709 2023-05-15T13:12:01+02:00 Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions Jäkel, Evelyn Carlsen, Tim Ehrlich, André Wendisch, Manfred Schäfer, Michael Rosenburg, Sophie Nakoudi, Konstantina Zanatta, Marco Birnbaum, Gerit Helm, Veit Herber, Andreas Istomina, Larysa Mai, Linlu Rohde, Anika 2021-12-03 application/pdf https://epic.awi.de/id/eprint/55709/ https://epic.awi.de/id/eprint/55709/1/2021_Jaekel-etal_Remotesensing.pdf https://www.mdpi.com/journal/remotesensing https://hdl.handle.net/10013/epic.5688e336-b2f1-4c75-a44f-a3b17052885c https://hdl.handle.net/ unknown MDPI https://epic.awi.de/id/eprint/55709/1/2021_Jaekel-etal_Remotesensing.pdf https://hdl.handle.net/ Jäkel, E. , Carlsen, T. , Ehrlich, A. , Wendisch, M. , Schäfer, M. , Rosenburg, S. , Nakoudi, K. , Zanatta, M. , Birnbaum, G. orcid:0000-0002-0252-6781 , Helm, V. orcid:0000-0001-7788-9328 , Herber, A. orcid:0000-0001-6651-3835 , Istomina, L. , Mai, L. and Rohde, A. (2021) Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions , Remote Sensing, 13 . doi:10390/rs13234904 , hdl:10013/epic.5688e336-b2f1-4c75-a44f-a3b17052885c EPIC3Remote Sensing, MDPI, 13 Article isiRev 2021 ftawi 2022-03-21T00:09:29Z The size and shape of snow grains directly impacts the reflection by a snowpack. In this article, different approaches to retrieve the optical-equivalent snow grain size (ropt) or, alternatively, the specific surface area (SSA) using satellite, airborne, and ground-based observations are compared and used to evaluate ICON-ART (ICOsahedral Nonhydrostatic—Aerosols and Reactive Trace gases) simulations. The retrieval methods are based on optical measurements and rely on the ropt-dependent absorption of solar radiation in snow. The measurement data were taken during a three-week campaign that was conducted in the North of Greenland in March/April 2018, such that the retrieval methods and radiation measurements are affected by enhanced uncertainties under these low-Sun conditions. An adjusted airborne retrieval method is applied which uses the albedo at 1700 nm wavelength and combines an atmospheric and snow radiative transfer model to account for the direct-to-global fraction of the solar radiation incident on the snow. From this approach, we achieved a significantly improved uncertainty (<25%) and a reduced effect of atmospheric masking compared to the previous method. Ground-based in situ measurements indicated an increase of ropt of 15 μm within a five-day period after a snowfall event which is small compared to previous observations under similar temperature regimes. ICON-ART captured the observed change of ropt during snowfall events, but systematically overestimated the subsequent snow grain growth by about 100%. Adjusting the growth rate factor to 0.012 μm2 s�1 minimized the difference between model and observations. Satellite-based and airborne retrieval methods showed higher ropt over sea ice (<300 μm) than over land surfaces (<100 μm) which was reduced by data filtering of surface roughness features. Moderate- Resolution Imaging Spectroradiometer (MODIS) retrievals revealed a large spread within a series of subsequent individual overpasses, indicating their limitations in observing the snow grain size evolution in early spring conditions with low Sun. Article in Journal/Newspaper albedo Arctic Arctic Greenland Sea ice Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic Greenland |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The size and shape of snow grains directly impacts the reflection by a snowpack. In this article, different approaches to retrieve the optical-equivalent snow grain size (ropt) or, alternatively, the specific surface area (SSA) using satellite, airborne, and ground-based observations are compared and used to evaluate ICON-ART (ICOsahedral Nonhydrostatic—Aerosols and Reactive Trace gases) simulations. The retrieval methods are based on optical measurements and rely on the ropt-dependent absorption of solar radiation in snow. The measurement data were taken during a three-week campaign that was conducted in the North of Greenland in March/April 2018, such that the retrieval methods and radiation measurements are affected by enhanced uncertainties under these low-Sun conditions. An adjusted airborne retrieval method is applied which uses the albedo at 1700 nm wavelength and combines an atmospheric and snow radiative transfer model to account for the direct-to-global fraction of the solar radiation incident on the snow. From this approach, we achieved a significantly improved uncertainty (<25%) and a reduced effect of atmospheric masking compared to the previous method. Ground-based in situ measurements indicated an increase of ropt of 15 μm within a five-day period after a snowfall event which is small compared to previous observations under similar temperature regimes. ICON-ART captured the observed change of ropt during snowfall events, but systematically overestimated the subsequent snow grain growth by about 100%. Adjusting the growth rate factor to 0.012 μm2 s�1 minimized the difference between model and observations. Satellite-based and airborne retrieval methods showed higher ropt over sea ice (<300 μm) than over land surfaces (<100 μm) which was reduced by data filtering of surface roughness features. Moderate- Resolution Imaging Spectroradiometer (MODIS) retrievals revealed a large spread within a series of subsequent individual overpasses, indicating their limitations in observing the snow grain size evolution in early spring conditions with low Sun. |
format |
Article in Journal/Newspaper |
author |
Jäkel, Evelyn Carlsen, Tim Ehrlich, André Wendisch, Manfred Schäfer, Michael Rosenburg, Sophie Nakoudi, Konstantina Zanatta, Marco Birnbaum, Gerit Helm, Veit Herber, Andreas Istomina, Larysa Mai, Linlu Rohde, Anika |
spellingShingle |
Jäkel, Evelyn Carlsen, Tim Ehrlich, André Wendisch, Manfred Schäfer, Michael Rosenburg, Sophie Nakoudi, Konstantina Zanatta, Marco Birnbaum, Gerit Helm, Veit Herber, Andreas Istomina, Larysa Mai, Linlu Rohde, Anika Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
author_facet |
Jäkel, Evelyn Carlsen, Tim Ehrlich, André Wendisch, Manfred Schäfer, Michael Rosenburg, Sophie Nakoudi, Konstantina Zanatta, Marco Birnbaum, Gerit Helm, Veit Herber, Andreas Istomina, Larysa Mai, Linlu Rohde, Anika |
author_sort |
Jäkel, Evelyn |
title |
Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
title_short |
Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
title_full |
Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
title_fullStr |
Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
title_full_unstemmed |
Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions |
title_sort |
measurements and modeling of optical-equivalent snow grain sizes under arctic low-sun conditions |
publisher |
MDPI |
publishDate |
2021 |
url |
https://epic.awi.de/id/eprint/55709/ https://epic.awi.de/id/eprint/55709/1/2021_Jaekel-etal_Remotesensing.pdf https://www.mdpi.com/journal/remotesensing https://hdl.handle.net/10013/epic.5688e336-b2f1-4c75-a44f-a3b17052885c https://hdl.handle.net/ |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
albedo Arctic Arctic Greenland Sea ice |
genre_facet |
albedo Arctic Arctic Greenland Sea ice |
op_source |
EPIC3Remote Sensing, MDPI, 13 |
op_relation |
https://epic.awi.de/id/eprint/55709/1/2021_Jaekel-etal_Remotesensing.pdf https://hdl.handle.net/ Jäkel, E. , Carlsen, T. , Ehrlich, A. , Wendisch, M. , Schäfer, M. , Rosenburg, S. , Nakoudi, K. , Zanatta, M. , Birnbaum, G. orcid:0000-0002-0252-6781 , Helm, V. orcid:0000-0001-7788-9328 , Herber, A. orcid:0000-0001-6651-3835 , Istomina, L. , Mai, L. and Rohde, A. (2021) Measurements and Modeling of Optical-Equivalent Snow Grain Sizes under Arctic Low-Sun Conditions , Remote Sensing, 13 . doi:10390/rs13234904 , hdl:10013/epic.5688e336-b2f1-4c75-a44f-a3b17052885c |
_version_ |
1766250046548869120 |