Climate response to solar forcing and greenhouse gas forcing

• Main Author: Gottschling, Martin
• Format: Thesis
• Language: English
• Published: 2009
• Subjects: Arctic; Climate change
• Online Access: https://oceanrep.geomar.de/id/eprint/59115/; https://oceanrep.geomar.de/id/eprint/59115/1/Dipl_Gottschling_M_2009.pdf

The impact of millennial solar forcing and carbon dioxide doubling on climate is studied based on simulations with a Coupled General Circulation Model so called Kiel Climate Model (KCM). Since solar insolation underlies an annual and daily cycle, it is suggested that surface air temperature change induced by solar shortwave forcing is spatially and temporarily more heterogeneous than in response to longwave carbon dioxide forcing. Moreover, solar forcing should act stronger in areas with generally clear-sky conditions as it generates stronger evaporation. The long-term mean daily and annual cycle of SAT is represented well by the model. No matter which of both forcing agents is considered, the response patterns look very similar. Strongest warming in case of both scenarios is observable in the Arctic during winter and at night. Thus, strongest warming is related to a composition of space and time, which is characterised by very limited solar insolation. This suggests, that dynamic processes and not the initial forcing dominate the climate change.