 |
| Titel |
Quantifying meltwater refreezing along a transect of sites on the Greenland ice sheet |
| VerfasserIn |
C. Cox, N. Humphrey, J. Harper |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 2 ; Nr. 9, no. 2 (2015-04-14), S.691-701 |
| Datensatznummer |
250116778
|
| Publikation (Nr.) |
 copernicus.org/tc-9-691-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| On the Greenland ice sheet, a significant quantity of surface meltwater
refreezes within the firn, creating uncertainty in surface mass balance
estimates. This refreezing has the potential to buffer seasonal runoff to
future increases in melting, but direct measurement of the process remains
difficult. We present a method for quantifying refreezing at point locations
using in situ firn temperature observations. A time series of sub-hourly firn
temperature profiles were collected over the course of two melt seasons from
2007 to 2009 along a transect of 11 sites in the accumulation zone of
Greenland. Seasonal changes in temperature profiles combined with heat flux
estimates based on high-temporal-resolution temperature gradients enable us
to isolate the heat released by refreezing using conservation of energy. Our
method is verified from winter data when no refreezing takes place, and
uncertainty is estimated using a Monte Carlo technique. While we limit our
method to a subsection of firn between depths of 1 and 10 m,
our refreezing estimates appear to differ significantly from model-based
estimates. Furthermore, results indicate that a significant amount of refreezing
takes place at depths greater than 1 m and that lateral migration of
meltwater significantly complicates the relationship between total surface
melt and total refreezing. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|