![Hier klicken, um den Treffer aus der Auswahl zu entfernen](images/unchecked.gif) |
Titel |
Sea ice radiative forcing, sea ice area, and climate sensitivity |
VerfasserIn |
Ken Caldeira, Ivana Cvijanovic |
Konferenz |
EGU General Assembly 2014
|
Medientyp |
Artikel
|
Sprache |
Englisch
|
Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250100034
|
Publikation (Nr.) |
EGU/EGU2014-15912.pdf |
|
|
|
Zusammenfassung |
Changes in sea ice cover affect climate sensitivity by modifying albedo and surface heat
flux exchange, which in turn affect the absorbed solar radiation at the surface as
well as cloud cover, atmospheric water content and poleward atmospheric heat
transport.
Here, we use a configuration of the Community Earth System Model 1.0.4 with a slab
ocean model and a thermodynamic-dynamic sea ice model to investigate the overall net effect
of feedbacks associated with the sea ice loss. We analyze the strength of the overall sea
ice feedback in terms of two factors: the sensitivity of sea ice area to changes in
temperature, and the sensitivity of sea ice radiative forcing to changes in sea ice
area.
In this model configuration, sea ice area decreases by ~3 x 1012 m2 per K of
global warming, while the effective global radiative forcing per square meter of sea
ice loss is ~0.1 x 10-12 W m-2. The product of these two terms (~0.3 W m-2
K-1) approximately equals the difference in climate feedback parameter found in
simulations with sea ice response (1.05 W m-2 K-1) and simulations without sea ice
response (1.31 W m-2 K-1 or 1.35 W m-2 K-1, depending on the method used to
disable changes in sea ice cover). Thus, we find that in our model simulations,
sea ice response accounts for about 20% to 22% of the climate sensitivity to an
imposed change in radiative forcing. In our model, the additional radiative forcing
resulting from a loss of all sea ice in the “pre-industrial” state is comparable to but
somewhat less than the radiative forcing from a doubling of atmospheric CO2 content. |
|
|
|
|
|