Berlin 2005 – wissenschaftliches Programm
EP 2.5: Fachvortrag
Freitag, 4. März 2005, 15:30–15:50, TU BH349
Modeling the sun’s influence on climate — •Ulrich Cubasch1, Eduardo Zorita2, and Frank Kaspar3 — 1Meteorologisches Institut der Freien Universität Berlin — 2GKSS Forschungsanstalt Geesthacht — 3Max-Planck-Institut für Meteorologie, Hamburg
The sun influences the climate in two ways: a) by varying strength and b) by changes of the orbital parameters of the earth around the sun. The first effect currently has drawn a lot of attention, as it is considered as on candidate to be responsible for the recently observed global warming. This effect has been studied in a number of experiments simulating the recent centuries before and during industrialization. The model simulates during the Late Maunder Minimum warming rates comparable to the ones observed at present. However, the warming observed recently cannot solely be attributed to changes in solar forcing. The orbital parameters take effect in more geological timescales. Here the interest focuses on the questions like the recent ice ages and warm periods as well as the transitions between ice ages and warm periods. A simulation for 125 ky bp, which was the last warm period (Eem) as well as for 115 ky bp, i. e. the transition between warm period and ice age will be presented. The simulation of the Eemian compares well with pollen derived proxy data, and the simulation of the 115 ky bp climate shows the built up of an ice sheet in the northern part of North America.