 |
| Titel |
The impact of climate-vegetation interactions on the onset of the Antarctic ice sheet |
| VerfasserIn |
Johan Liakka, Florence Colleoni, Bodo Ahrens, Thomas Hickler |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250088757
|
| Publikation (Nr.) |
 EGU/EGU2014-2902.pdf |
|
|
|
|
|
| Zusammenfassung |
| A global coupled atmosphere/vegetation model and a dynamic ice-sheet model were
employed to study the impact of climate-vegetation interactions on the onset of the Antarctic
ice sheet at the Eocene/Oligocene boundary. We found that the CO2 threshold for Antarctic
glaciation is highly sensitive to the prevailing vegetation. In our experiments, the CO2
threshold is less than 280 ppm if the Antarctic vegetation is dominated by forests,
and between 560 and 1120 ppm for tundra and bare ground conditions. The large
impact of vegetation on inception is attributed to the ability of canopies to shade the
snow-covered ground, which leads to a weaker snow-albedo feedback and higher summer
temperatures. However, ultimately the effect of canopy shading also depends on the
local cloud conditions and the meridional heat transport. Our results suggest that
vegetation feedbacks on climate are crucial for the timing of the Antarctic glaciation. |
|
|
|
|
|
|