SOLID - a European FP7 project towards the first European comprehensive solar irradiance data exploitation
Résumé
Variations of solar irradiance are the most important natural factor in driving the terrestrial climate. In particular, it is the time dependent spectral solar irradiance (SSI) that is a crucial input to any climate modelling. There have been previous efforts to compile SSI, but it is still uncertain by how much the spectral and total solar irradiance changed on yearly, decadal and longer time scales. Observations of irradiance data exist in numerous disperse data sets. Therefore, it is important to bring together the European expertise in the field to analyse and merge the complete set of European irradiance data, complemented by archive data that include data from non-European missions. SOLID includes all European groups involved in irradiance modelling and reconstruction. They will work with two different state of the art approaches to produce reconstructed spectral and total solar irradiance data as a function of time. These results will be used to bridge gaps in time and wavelength coverage of the observational data. This will allow to reduce the uncertainties in the irradiance time series - an important requirement by the climate community - and to provide uniform data sets of modelled and observed solar irradiance data from the beginning of the space era to the present including detailed error and uncertainty estimates. The spectral irradiance time series, ranging from the EUV to the IR spectral range, are particularly important for the climate modeling community as well as modellers of the Earth ́s ionosphere. Within SOLID a wide international synergy in solar physics from 7 European countries, and collaborators from the US, complemented by representatives from the climate community, who will accompany their research work with wide dissemination activities.