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| Titel |
A new albedo parameterization for the use in climate models over ice sheets |
| VerfasserIn |
Peter Kuipers Munneke, Michiel van den Broeke, Jan Lenaerts, Mark Flanner, Alex Gardner, Willem Jan van de Berg |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045560
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| Zusammenfassung |
| A physically based parameterization for the broadband albedo of snow is included in a
regional climate model (RACMO2.1/ANT) for Antarctica, and validated against field
observations for the period 1995–2004. The parameterization is based on snow grain size
evolution, cloud optical thickness, and solar zenith angle. Over the Antarctic continent,
modeled snow grain size exhibits expected behaviour. The agreement between modeled and
observed albedo is very good when compared to measurements taken at Neumayer, Dronning
Maud Land. The new parameterization does a good job at simulating subtle changes in the
observed albedo. December–February mean differences in modeled and observed
net shortwave radiation range from –3.8 to +8.7 W m-2 between 1995 and 2004,
with a mean bias of +2.7 W m-2. This is a considerable improvement over the
previous RACMO2.1/ANT albedo parameterization, that overestimated the net
shortwave fluxes by +15.0 to +22.7 W m-2, or 40–55% of the observed net shortwave
flux over the same period. The improved simulation of ice sheet albedo opens up
possibilities to use melt extent, duration and volume as indicators for climate change. |
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