Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends
Monitoring snow cover to infer climate change impacts is now feasible using Earth observation data together with reanalysis products derived from Earth system models and data assimilation. Temporal stability becomes essential when these products are used to monitor snow cover changes over time. Whil...
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ftdoajarticles:oai:doaj.org/article:f80e2b0977484c62a256adc79d39ad97 2023-05-15T18:32:25+02:00 Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends R. Urraca N. Gobron 2023-03-01T00:00:00Z https://doi.org/10.5194/tc-17-1023-2023 https://doaj.org/article/f80e2b0977484c62a256adc79d39ad97 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/1023/2023/tc-17-1023-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1023-2023 1994-0416 1994-0424 https://doaj.org/article/f80e2b0977484c62a256adc79d39ad97 The Cryosphere, Vol 17, Pp 1023-1052 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-1023-2023 2023-03-05T01:31:36Z Monitoring snow cover to infer climate change impacts is now feasible using Earth observation data together with reanalysis products derived from Earth system models and data assimilation. Temporal stability becomes essential when these products are used to monitor snow cover changes over time. While the temporal stability of satellite products can be altered when multiple sensors are combined and due to the degradation and orbital drifts in each sensor, the stability of reanalysis datasets can be compromised when new observations are assimilated into the model. This study evaluates the stability of some of the longest satellite-based and reanalysis products (ERA5, 1950–2020, ERA5-Land, 1950–2020, and the National Oceanic and Atmospheric Administration Climate Data Record (NOAA CDR), 1966–2020) by using 527 ground stations as reference data (1950–2020). Stability is assessed with the time series of the annual bias in snow depth and snow cover duration of the products at the different stations. Reanalysis datasets face a trade-off between accuracy and stability when assimilating new data to improve their estimations. The assimilation of new observations in ERA5 improved its accuracy significantly during the recent years (2005–2020) but introduced three negative step discontinuities in 1977–1980, 1991–1992, and 2003–2004. By contrast, ERA5-Land is more stable because it does not assimilate snow observations directly, but this leads to worse accuracy despite having a finer spatial resolution. The NOAA CDR showed a positive artificial trend from around 1992 to 2015 during fall and winter that could be related to changes to the availability of satellite data. The magnitude of most of these artificial trends and/or discontinuities is larger than actual snow cover trends and the stability requirements of the Global Climate Observing System (GCOS). The use of these products in seasons and regions where artificial trends and discontinuities appear should be avoided. The study also updates snow trends (1955–2015) over ... Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 17 2 1023 1052 |
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Environmental sciences GE1-350 Geology QE1-996.5 |
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Environmental sciences GE1-350 Geology QE1-996.5 R. Urraca N. Gobron Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Monitoring snow cover to infer climate change impacts is now feasible using Earth observation data together with reanalysis products derived from Earth system models and data assimilation. Temporal stability becomes essential when these products are used to monitor snow cover changes over time. While the temporal stability of satellite products can be altered when multiple sensors are combined and due to the degradation and orbital drifts in each sensor, the stability of reanalysis datasets can be compromised when new observations are assimilated into the model. This study evaluates the stability of some of the longest satellite-based and reanalysis products (ERA5, 1950–2020, ERA5-Land, 1950–2020, and the National Oceanic and Atmospheric Administration Climate Data Record (NOAA CDR), 1966–2020) by using 527 ground stations as reference data (1950–2020). Stability is assessed with the time series of the annual bias in snow depth and snow cover duration of the products at the different stations. Reanalysis datasets face a trade-off between accuracy and stability when assimilating new data to improve their estimations. The assimilation of new observations in ERA5 improved its accuracy significantly during the recent years (2005–2020) but introduced three negative step discontinuities in 1977–1980, 1991–1992, and 2003–2004. By contrast, ERA5-Land is more stable because it does not assimilate snow observations directly, but this leads to worse accuracy despite having a finer spatial resolution. The NOAA CDR showed a positive artificial trend from around 1992 to 2015 during fall and winter that could be related to changes to the availability of satellite data. The magnitude of most of these artificial trends and/or discontinuities is larger than actual snow cover trends and the stability requirements of the Global Climate Observing System (GCOS). The use of these products in seasons and regions where artificial trends and discontinuities appear should be avoided. The study also updates snow trends (1955–2015) over ... |
format |
Article in Journal/Newspaper |
author |
R. Urraca N. Gobron |
author_facet |
R. Urraca N. Gobron |
author_sort |
R. Urraca |
title |
Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
title_short |
Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
title_full |
Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
title_fullStr |
Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
title_full_unstemmed |
Temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
title_sort |
temporal stability of long-term satellite and reanalysis products to monitor snow cover trends |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-1023-2023 https://doaj.org/article/f80e2b0977484c62a256adc79d39ad97 |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 1023-1052 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/1023/2023/tc-17-1023-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1023-2023 1994-0416 1994-0424 https://doaj.org/article/f80e2b0977484c62a256adc79d39ad97 |
op_doi |
https://doi.org/10.5194/tc-17-1023-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
2 |
container_start_page |
1023 |
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1052 |
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1766216536945590272 |