The Influence of Solar Variability on Climate (SOLVO)

Principal investigator: PD Dr. Ulrike Langematz, Prof. Dr. Ulrich Cubasch

Scientist: Dr. Katja Matthes



The fundamental energy source of the climate system is the Sun. Variability of the solar radiation is one potential source of climate change. Variations in the thermal, dynamical and chemical structure of the atmosphere have been observed that can be attributed to 11-year solar irradiance variations. Since the advent of satellites in the late 1970s global atmospheric and solar variability data have been collected. Together with numerical models of the atmosphere they allow the study of the solar influence on climate. However, current general circulation models (GCMs) have an insufficient representation of atmospheric chemistry and are restricted to the lower parts of the atmosphere. They are therefore not capable of reproducing the observed Sun-climate interactions.


The aim of this project is to investigate the solar influence on climate with a GCM recently developed at the National Center for Atmospheric Research (NCAR) in Boulder, USA. The model is the first that has been designed specifically to investigate the interaction between radiation, chemistry and dynamics from the Earth’s surface to the thermosphere (140 km). The close collaboration with NCAR’s experienced model team ensures the realization of the project which adds new aspects to previous work with GCMs looking for the mechanism of Sun-climate interactions.


This study provides the opportunity to work on a highly interdisciplinary topic at an internationally renowned institution and to transfer the acquired knowledge as well as the unique model to Europe and the Free University of Berlin, Germany. The knowledge and experience gained in this project will be valuable to the EU research community in order to better determine the underlying natural variability of the atmosphere and to better estimate the anthropogenic contribution to the recent global warming. This will improve the accuracy of future climate predictions in forthcoming Intergovernmental Panel on Climate Change (IPCC) reports.