Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends
Sea ice volume has decreased in the last decades, evoked by changes in sea ice area and thickness. Estimates of sea ice area and thickness rely on a number of geophysical parameters which introduce large uncertainties. To quantify these uncertainties we use freeboard retrievals from ICESat and inves...
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ftdoajarticles:oai:doaj.org/article:3c4fba817f48456e9410499069d112b5 2023-05-15T14:29:19+02:00 Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends M. Zygmuntowska P. Rampal N. Ivanova L. H. Smedsrud 2014-04-01T00:00:00Z https://doi.org/10.5194/tc-8-705-2014 https://doaj.org/article/3c4fba817f48456e9410499069d112b5 EN eng Copernicus Publications http://www.the-cryosphere.net/8/705/2014/tc-8-705-2014.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-8-705-2014 https://doaj.org/article/3c4fba817f48456e9410499069d112b5 The Cryosphere, Vol 8, Iss 2, Pp 705-720 (2014) Environmental sciences GE1-350 Geology QE1-996.5 article 2014 ftdoajarticles https://doi.org/10.5194/tc-8-705-2014 2022-12-31T09:46:22Z Sea ice volume has decreased in the last decades, evoked by changes in sea ice area and thickness. Estimates of sea ice area and thickness rely on a number of geophysical parameters which introduce large uncertainties. To quantify these uncertainties we use freeboard retrievals from ICESat and investigate different assumptions about snow depth, sea ice density and area. We find that uncertainties in ice area are of minor importance for the estimates of sea ice volume during the cold season in the Arctic basin. The choice of mean ice density used when converting sea ice freeboard into thickness mainly influences the resulting mean sea ice thickness, while snow depth on top of the ice is the main driver for the year-to-year variability, particularly in late winter. The absolute uncertainty in the mean sea ice thickness is 0.28 m in February/March and 0.21 m in October/November. The uncertainty in snow depth contributes up to 70% of the total uncertainty and the ice density 30–35%, with higher values in October/November. We find large uncertainties in the total sea ice volume and trend. The mean total sea ice volume is 10 120 ± 1280 km 3 in October/November and 13 250 ± 1860 km 3 in February/March for the time period 2005–2007. Based on these uncertainties we obtain trends in sea ice volume of −1450 ± 530 km 3 a −1 in October/November and −880 ± 260 km 3 a −1 in February/March over the ICESat period (2003–2008). Our results indicate that, taking into account the uncertainties, the decline in sea ice volume in the Arctic between the ICESat (2003–2008) and CryoSat-2 (2010–2012) periods may have been less dramatic than reported in previous studies. However, more work and validation is required to quantify these changes and analyse possible unresolved biases in the freeboard retrievals. Article in Journal/Newspaper Arctic Basin Arctic Sea ice The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic The Cryosphere 8 2 705 720 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Zygmuntowska P. Rampal N. Ivanova L. H. Smedsrud Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Sea ice volume has decreased in the last decades, evoked by changes in sea ice area and thickness. Estimates of sea ice area and thickness rely on a number of geophysical parameters which introduce large uncertainties. To quantify these uncertainties we use freeboard retrievals from ICESat and investigate different assumptions about snow depth, sea ice density and area. We find that uncertainties in ice area are of minor importance for the estimates of sea ice volume during the cold season in the Arctic basin. The choice of mean ice density used when converting sea ice freeboard into thickness mainly influences the resulting mean sea ice thickness, while snow depth on top of the ice is the main driver for the year-to-year variability, particularly in late winter. The absolute uncertainty in the mean sea ice thickness is 0.28 m in February/March and 0.21 m in October/November. The uncertainty in snow depth contributes up to 70% of the total uncertainty and the ice density 30–35%, with higher values in October/November. We find large uncertainties in the total sea ice volume and trend. The mean total sea ice volume is 10 120 ± 1280 km 3 in October/November and 13 250 ± 1860 km 3 in February/March for the time period 2005–2007. Based on these uncertainties we obtain trends in sea ice volume of −1450 ± 530 km 3 a −1 in October/November and −880 ± 260 km 3 a −1 in February/March over the ICESat period (2003–2008). Our results indicate that, taking into account the uncertainties, the decline in sea ice volume in the Arctic between the ICESat (2003–2008) and CryoSat-2 (2010–2012) periods may have been less dramatic than reported in previous studies. However, more work and validation is required to quantify these changes and analyse possible unresolved biases in the freeboard retrievals. |
format |
Article in Journal/Newspaper |
author |
M. Zygmuntowska P. Rampal N. Ivanova L. H. Smedsrud |
author_facet |
M. Zygmuntowska P. Rampal N. Ivanova L. H. Smedsrud |
author_sort |
M. Zygmuntowska |
title |
Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
title_short |
Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
title_full |
Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
title_fullStr |
Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
title_full_unstemmed |
Uncertainties in Arctic sea ice thickness and volume: new estimates and implications for trends |
title_sort |
uncertainties in arctic sea ice thickness and volume: new estimates and implications for trends |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/tc-8-705-2014 https://doaj.org/article/3c4fba817f48456e9410499069d112b5 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Basin Arctic Sea ice The Cryosphere |
genre_facet |
Arctic Basin Arctic Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 8, Iss 2, Pp 705-720 (2014) |
op_relation |
http://www.the-cryosphere.net/8/705/2014/tc-8-705-2014.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-8-705-2014 https://doaj.org/article/3c4fba817f48456e9410499069d112b5 |
op_doi |
https://doi.org/10.5194/tc-8-705-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
2 |
container_start_page |
705 |
op_container_end_page |
720 |
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1766303359736741888 |