SOLVO · The influence of solar variability on climate
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2003-05-15 → 2006-05-14
- EU contribution
- €257,169
- Participants
- 1
- Scheme
- OIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - SOLVO (The Influence of Solar Variability on Climate)
The sun is the fundamental energy source of the climate system. Hence changes in solar irradiance are one potential source of natural climate variability. Observational and previous modelling studies have shown that direct radiative changes in the upper stratosphere can lead to indirect dynamical changes throughout the atmosphere. However, previous General circulation models (GCMs) had an insufficient representation of atmospheric chemistry and were restricted to the lower parts of the atmosphere. Observational data sets are short and make it difficult to extract reliable decadal signals. Therefore modelling studies are useful to enhance the understanding of the underlying physical mechanism(s). The aim of this project was to investigate the solar influence on climate with a model that was specifically designed to look at interactions between radiation, chemistry and dynamics from the Earth's surface to the thermosphere (~140 km). A unique set of (idealised) experiments with the Whole atmosphere community climate model (WACCM) developed at the National Center for Atmospheric Research (NCAR) in Boulder, United States (US), was performed during the project to investigate the response of the atmosphere to 11-year solar cycle changes and especially interactions with the equatorial stratospheric wind oscillation (QBO) for which observational evidence is strong. Through the analysis of a systematic set of model simulations with WACCM (under different constant or time-varying solar cycle and QBO forcings) it was possible to confirm the observed evidence for a dependence of the solar signal on the phase of the QBO at polar winter latitudes as well as an influence on large-scale atmospheric circulation patterns. This enhances the understanding of the role of the QBO for the chemical-dynamical response to the solar cycle and contributes to a better understanding of the mechanism for Sun-climate interactions and natural climate variability in general. A better understanding of natural climate variability is essential to reliably estimate the anthropogenic contribution to the recent global warming and to improve the accuracy of climate predictions in forthcoming Intergovernmental Panel on Climate Change (IPCC) reports and World Meteorological Organisation (WMO) ozone assessments.
Data: CORDIS, © European Union
Project objective
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 attri buted 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 o n 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 inter actions. 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 investigat e 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 wit h 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 Eu rope 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.
Original text from CORDIS.
Participants
- FREIE UNIVERSITAET BERLIN · BERLINCoordinatorGermany
Links
Data: CORDIS, © European Union