SOLAR
Solar Forcing and Climate Change of the last 1000 years
The climate system on Earth is powered by solar energy. The Earth receives about 2 1017 W from the Sun in the form of electromagnetic radiation (mostly as visible light). Other contributions from particles (solar wind) and magnetic fields are many orders of magnitude smaller. The Sun is a variable star. Measurements from satellites during the past 30 years show that the solar constant is not constant and varies with the solar magnetic activity. Cosmogenic radionuclides such as 10Be in polar ice and 14C in tree rings provide the key to reconstruct solar variability over at least 10,000 years. Reconstructing these variations for the past is important for:
- understanding past climate changes
- improving solar models (dynamo)
- testing climate (GCM) models
- estimating the Sun’s role in future global warming
This project is linked to workpackage 1: Reconstructing and Modelling Past Drought Variability [...]
More information [...]
Funding
Picture 1 & 2 on top: The Sun interacts with the Earth by particles forming the solar wind and causing northern lights, by magnetic fields frozen into the solar wind and causing communication problems, and most importantly by electromagnetic radiation powering life and the climate system.
Picture 3 on top: Length fluctuations of the Aletsch Glacier
The Great Aletsch glacier in the Swiss Alps retreated and advanced several times over the past 3000 years (Holzhauser et al 2005). These length fluctuations have some similarities with the total solar irradiance (solar constant, red curve).