Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)

Large-scale changes in Arctic sea ice thickness, volume and multiyear sea ice (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat and CryoSat-2), and satellite scatterometers are summarized. The submarine record spans the period between 1958 and 2000, the s...

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Main Author: R Kwok
Format: Article
Language:English
Published: IOP Publishing 2018-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/aae3ec
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author R Kwok
author_facet R Kwok
author_sort R Kwok
collection DOAJ
description Large-scale changes in Arctic sea ice thickness, volume and multiyear sea ice (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat and CryoSat-2), and satellite scatterometers are summarized. The submarine record spans the period between 1958 and 2000, the satellite altimeter records between 2003 and 2018, and the scatterometer records between 1999 and 2017. Regional changes in ice thickness (since 1958) and within the data release area of the Arctic Ocean, previously reported by Kwok and Rothrock (2009 Geophys. Res. Lett. 36 L15501), have been updated to include the 8 years of CryoSat-2 (CS-2) retrievals. Between the pre-1990 submarine period (1958–1976) and the CS-2 period (2011–2018) the average thickness near the end of the melt season, in six regions, decreased by 2.0 m or some 66% over six decades. Within the data release area (∼38% of the Arctic Ocean) of submarine ice draft, the thinning of ∼1.75 m in winter since 1980 (maximum thickness of 3.64 m in the regression analysis) has not changed significantly; the mean thickness over the CS-2 period is ∼2 m. The 15 year satellite record depicts losses in sea ice volume at 2870 km ^3 /decade and 5130 km ^3 /decade in winter (February–March) and fall (October–November), respectively: more moderate trends compared to the sharp decreases over the ICESat period, where the losses were weighted by record-setting melt in 2007. Over the scatterometer record (1999–2017), the Arctic has lost more than 2 × 10 ^6 km ^2 of MYI—a decrease of more than 50%; MYI now covers less than one-third of the Arctic Ocean. Independent MYI coverage and volume records co-vary in time, the MYI area anomalies explain ∼85% of the variance in the anomalies in Arctic sea ice volume. If losses of MYI continue, Arctic thickness/volume will be controlled by seasonal ice, suggesting that the thickness/volume trends will be more moderate (as seen here) but more sensitive to climate forcing.
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spelling doaj.art-0ce2a67754804fb19034db7cf0cf3ea42023-08-09T14:37:33ZengIOP PublishingEnvironmental Research Letters1748-93262018-01-01131010500510.1088/1748-9326/aae3ecArctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)R Kwok0https://orcid.org/0000-0003-4051-5896Jet Propulsion Laboratory, California Institute of Technology, Pasadena , CA 91109, United States of AmericaLarge-scale changes in Arctic sea ice thickness, volume and multiyear sea ice (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat and CryoSat-2), and satellite scatterometers are summarized. The submarine record spans the period between 1958 and 2000, the satellite altimeter records between 2003 and 2018, and the scatterometer records between 1999 and 2017. Regional changes in ice thickness (since 1958) and within the data release area of the Arctic Ocean, previously reported by Kwok and Rothrock (2009 Geophys. Res. Lett. 36 L15501), have been updated to include the 8 years of CryoSat-2 (CS-2) retrievals. Between the pre-1990 submarine period (1958–1976) and the CS-2 period (2011–2018) the average thickness near the end of the melt season, in six regions, decreased by 2.0 m or some 66% over six decades. Within the data release area (∼38% of the Arctic Ocean) of submarine ice draft, the thinning of ∼1.75 m in winter since 1980 (maximum thickness of 3.64 m in the regression analysis) has not changed significantly; the mean thickness over the CS-2 period is ∼2 m. The 15 year satellite record depicts losses in sea ice volume at 2870 km ^3 /decade and 5130 km ^3 /decade in winter (February–March) and fall (October–November), respectively: more moderate trends compared to the sharp decreases over the ICESat period, where the losses were weighted by record-setting melt in 2007. Over the scatterometer record (1999–2017), the Arctic has lost more than 2 × 10 ^6 km ^2 of MYI—a decrease of more than 50%; MYI now covers less than one-third of the Arctic Ocean. Independent MYI coverage and volume records co-vary in time, the MYI area anomalies explain ∼85% of the variance in the anomalies in Arctic sea ice volume. If losses of MYI continue, Arctic thickness/volume will be controlled by seasonal ice, suggesting that the thickness/volume trends will be more moderate (as seen here) but more sensitive to climate forcing.https://doi.org/10.1088/1748-9326/aae3ecArctic sea ice thicknessArctic sea ice volumeArctic multiyear sea ice coverage
spellingShingle R Kwok
Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
Environmental Research Letters
Arctic sea ice thickness
Arctic sea ice volume
Arctic multiyear sea ice coverage
title Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
title_full Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
title_fullStr Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
title_full_unstemmed Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
title_short Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
title_sort arctic sea ice thickness volume and multiyear ice coverage losses and coupled variability 1958 2018
topic Arctic sea ice thickness
Arctic sea ice volume
Arctic multiyear sea ice coverage
url https://doi.org/10.1088/1748-9326/aae3ec
work_keys_str_mv AT rkwok arcticseaicethicknessvolumeandmultiyearicecoveragelossesandcoupledvariability19582018