 |
| Titel |
Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations |
| VerfasserIn |
R. Lindsay, A. Schweiger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 1 ; Nr. 9, no. 1 (2015-02-10), S.269-283 |
| Datensatznummer |
250116750
|
| Publikation (Nr.) |
 copernicus.org/tc-9-269-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Sea ice thickness is a fundamental climate state variable that provides an
integrated measure of changes in the high-latitude energy balance. However,
observations of mean ice thickness have been sparse in time and space, making
the construction of observation-based time series difficult. Moreover,
different groups use a variety of methods and processing procedures to
measure ice thickness, and each observational source likely has different and
poorly characterized measurement and sampling errors. Observational sources
used in this study include upward-looking sonars mounted on submarines or
moorings, electromagnetic sensors on helicopters or aircraft, and lidar or
radar altimeters on airplanes or satellites. Here we use a curve-fitting
approach to determine the large-scale spatial and temporal variability of
the ice thickness as well as the mean differences between the observation
systems, using over 3000 estimates of the ice thickness. The thickness
estimates are measured over spatial scales of approximately 50 km or time
scales of 1 month, and the primary time period analyzed is 2000–2012 when
the modern mix of observations is available. Good agreement is found between
five of the systems, within 0.15 m, while systematic differences of up to
0.5 m are found for three others compared to the five. The trend in annual
mean ice thickness over the Arctic Basin is −0.58 ± 0.07 m decade−1
over the period 2000–2012. Applying our method to the period
1975–2012 for the central Arctic Basin where we have sufficient data (the SCICEX
box), we find that the annual mean ice thickness has decreased from 3.59 m
in 1975 to 1.25 m in 2012, a 65% reduction. This is nearly double the
36% decline reported by an earlier study. These results provide
additional direct observational evidence of substantial sea ice losses found
in model analyses. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|