Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014
The timing and intensity of snowmelt processes on sea ice are key drivers determining the seasonal sea-ice energy and mass budgets. In the Arctic, satellite passive microwave and radar observations have revealed a trend towards an earlier snowmelt onset during the last decades, which is an important...
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ftdatacite:10.1594/pangaea.903225 2023-05-15T14:05:25+02:00 Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 Arndt, Stefanie Haas, Christian 2019 text/tab-separated-values https://dx.doi.org/10.1594/pangaea.903225 https://doi.pangaea.de/10.1594/PANGAEA.903225 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.5194/tc-2019-27 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Antarctic Sea ice snow snowmelt LATITUDE LONGITUDE Initial snowmelt onset in days after January 0, 0000 Snowmelt onset after January 0, 0000 Snowmelt onset from diurnal variations after January 0, 0000 Dataset dataset 2019 ftdatacite https://doi.org/10.1594/pangaea.903225 https://doi.org/10.5194/tc-2019-27 2022-02-09T13:17:41Z The timing and intensity of snowmelt processes on sea ice are key drivers determining the seasonal sea-ice energy and mass budgets. In the Arctic, satellite passive microwave and radar observations have revealed a trend towards an earlier snowmelt onset during the last decades, which is an important aspect of Arctic amplification and sea ice decline. Around Antarctica, snowmelt on perennial ice is weak and very different than in the Arctic, with most snow surviving the summer.Here we compile time series of snowmelt-onset dates on seasonal and perennial Antarctic sea ice from 1992 to 2014/15 using active microwave observations from European Remote Sensing Satellite (ERS-1/2), Quick Scatterometer (QSCAT) and Advanced Scatterometer (ASCAT) radar scatterometers. We define two snowmelt transition stages: A weak backscatter rise indicating the initial warming and metamorphism of the snowpack (pre-melt), followed by a rapid backscatter rise indicating the onset of thaw-freeze cycles (snowmelt).Results show large interannual variability with an average pre-melt onset date of 29 November and melt onset of 10 December, respectively, on perennial ice, without any significant trends over the study period, consistent with the small trends of Antarctic sea ice extent. There was a latitudinal gradient from early snowmelt onsets in mid-November in the northern Weddell Sea to late (end-December) or even absent snowmelt conditions in the southern Weddell Sea.We show that QSCAT Ku-band (13.4 GHz signal frequency) derived pre-melt and snowmelt onset dates are earlier by 25 and 11 days, respectively, than ERS and ASCAT C-band (5.6 GHz) derived dates. This offset has been considered when constructing the time series. Snowmelt onset dates from passive microwave observations (37 GHz) are later by 13 and 5 days than those from the scatterometers, respectively.Based on these characteristic differences between melt onset dates observed by different microwave wavelengths, we developed a conceptual model which illustrates how the evolution of seasonal snow temperature profiles affects different microwave bands with different penetration depths. These suggest that future multi-frequency active/passive microwave satellite missions could be used to resolve melt processes throughout the vertical snow column. Dataset Antarc* Antarctic Antarctica Arctic Sea ice Weddell Sea DataCite Metadata Store (German National Library of Science and Technology) Antarctic Arctic Weddell Weddell Sea |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Antarctic Sea ice snow snowmelt LATITUDE LONGITUDE Initial snowmelt onset in days after January 0, 0000 Snowmelt onset after January 0, 0000 Snowmelt onset from diurnal variations after January 0, 0000 |
spellingShingle |
Antarctic Sea ice snow snowmelt LATITUDE LONGITUDE Initial snowmelt onset in days after January 0, 0000 Snowmelt onset after January 0, 0000 Snowmelt onset from diurnal variations after January 0, 0000 Arndt, Stefanie Haas, Christian Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
topic_facet |
Antarctic Sea ice snow snowmelt LATITUDE LONGITUDE Initial snowmelt onset in days after January 0, 0000 Snowmelt onset after January 0, 0000 Snowmelt onset from diurnal variations after January 0, 0000 |
description |
The timing and intensity of snowmelt processes on sea ice are key drivers determining the seasonal sea-ice energy and mass budgets. In the Arctic, satellite passive microwave and radar observations have revealed a trend towards an earlier snowmelt onset during the last decades, which is an important aspect of Arctic amplification and sea ice decline. Around Antarctica, snowmelt on perennial ice is weak and very different than in the Arctic, with most snow surviving the summer.Here we compile time series of snowmelt-onset dates on seasonal and perennial Antarctic sea ice from 1992 to 2014/15 using active microwave observations from European Remote Sensing Satellite (ERS-1/2), Quick Scatterometer (QSCAT) and Advanced Scatterometer (ASCAT) radar scatterometers. We define two snowmelt transition stages: A weak backscatter rise indicating the initial warming and metamorphism of the snowpack (pre-melt), followed by a rapid backscatter rise indicating the onset of thaw-freeze cycles (snowmelt).Results show large interannual variability with an average pre-melt onset date of 29 November and melt onset of 10 December, respectively, on perennial ice, without any significant trends over the study period, consistent with the small trends of Antarctic sea ice extent. There was a latitudinal gradient from early snowmelt onsets in mid-November in the northern Weddell Sea to late (end-December) or even absent snowmelt conditions in the southern Weddell Sea.We show that QSCAT Ku-band (13.4 GHz signal frequency) derived pre-melt and snowmelt onset dates are earlier by 25 and 11 days, respectively, than ERS and ASCAT C-band (5.6 GHz) derived dates. This offset has been considered when constructing the time series. Snowmelt onset dates from passive microwave observations (37 GHz) are later by 13 and 5 days than those from the scatterometers, respectively.Based on these characteristic differences between melt onset dates observed by different microwave wavelengths, we developed a conceptual model which illustrates how the evolution of seasonal snow temperature profiles affects different microwave bands with different penetration depths. These suggest that future multi-frequency active/passive microwave satellite missions could be used to resolve melt processes throughout the vertical snow column. |
format |
Dataset |
author |
Arndt, Stefanie Haas, Christian |
author_facet |
Arndt, Stefanie Haas, Christian |
author_sort |
Arndt, Stefanie |
title |
Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
title_short |
Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
title_full |
Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
title_fullStr |
Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
title_full_unstemmed |
Onset dates from annual snowmelt on Antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
title_sort |
onset dates from annual snowmelt on antarctic sea ice from satellite scatterometer observations from 1992 to 2014 |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
2019 |
url |
https://dx.doi.org/10.1594/pangaea.903225 https://doi.pangaea.de/10.1594/PANGAEA.903225 |
geographic |
Antarctic Arctic Weddell Weddell Sea |
geographic_facet |
Antarctic Arctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctica Arctic Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Arctic Sea ice Weddell Sea |
op_relation |
https://dx.doi.org/10.5194/tc-2019-27 |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.903225 https://doi.org/10.5194/tc-2019-27 |
_version_ |
1766277308641968128 |