 |
| Titel |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
| VerfasserIn |
G. H. Gudmundsson, M. Raymond |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 2, no. 2 ; Nr. 2, no. 2 (2008-12-05), S.167-178 |
| Datensatznummer |
250000533
|
| Publikation (Nr.) |
 copernicus.org/tc-2-167-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| An optimal estimation method for simultaneously determining both basal
slipperiness and basal topography from variations in surface flow
velocity and topography along a flow line on ice streams and ice
sheets is presented. We use Bayesian inference to update prior
statistical estimates for basal topography and slipperiness using
surface measurements along a flow line. Our main focus here is on how
errors and spacing of surface data affect estimates of basal
quantities and on possibly aliasing/mixing between basal slipperiness
and basal topography. We find that the effects of spatial variations
in basal topography and basal slipperiness on surface data can be
accurately separated from each other, and mixing in retrieval does not
pose a serious problem. For realistic surface data errors and density,
small-amplitude perturbations in basal slipperiness can only be
resolved for wavelengths larger than about 50 times the mean ice
thickness. Bedrock topography is well resolved down to horizontal
scale equal to about one ice thickness. Estimates of basal
slipperiness are not significantly improved by accurate prior
estimates of basal topography. However, retrieval of basal
slipperiness is found to be highly sensitive to unmodelled errors in
basal topography. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|