 |
| Titel |
The relation between sea ice thickness and freeboard in the Arctic |
| VerfasserIn |
V. Alexandrov, S. Sandven, J. Wahlin, O. M. Johannessen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 4, no. 3 ; Nr. 4, no. 3 (2010-09-20), S.373-380 |
| Datensatznummer |
250001770
|
| Publikation (Nr.) |
 copernicus.org/tc-4-373-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Retrieval of Arctic sea ice thickness from CryoSat-2 radar altimeter
freeboard data requires observational data to verify the relation between
these two variables. In this study in-situ ice and snow data from 689
observation sites, obtained during the Sever expeditions in the 1980s, have
been used to establish an empirical relation between thickness and freeboard
of FY ice in late winter. Estimates of mean and variability of snow depth,
snow density and ice density were produced on the basis of many field
observations. These estimates have been used in the hydrostatic equilibrium
equation to retrieve ice thickness as a function of ice freeboard, snow
depth and snow/ice density. The accuracy of the ice thickness retrieval has
been calculated from the estimated variability in ice and snow parameters
and error of ice freeboard measurements. It is found that uncertainties of
ice density and freeboard are the major sources of error in ice thickness
calculation. For FY ice, retrieval of ≈ 1.0 m (2.0 m) thickness has
an uncertainty of 46% (37%), and for MY ice, retrieval of 2.4 m (3.0 m)
thickness has an uncertainty of 20% (18%), assuming that the
freeboard error is ± 0.03 m for both ice types. For MY ice the
main uncertainty is ice density error, since the freeboard error is
relatively smaller than that for FY ice. If the freeboard error can be
reduced to 0.01 m by averaging measurements from CryoSat-2, the error in
thickness retrieval is reduced to about 32% for a 1.0 m thick FY floe and
to about 18% for a 2.4 m thick MY floe. The remaining error is dominated
by uncertainty in ice density. Provision of improved ice density data is
therefore important for accurate retrieval of ice thickness from CryoSat-2
data. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|