A new observational solar spectral irradiance composite

International audienceVariations in the solar spectral irradiance (SSI) are an important driver of the chemistry, temperature, and dynamics of the Earth's atmosphere and ultimately the Earth's climate. To investigate the detailed response of the Earth's atmosphere to SSI variations, a reliable SSI data set is needed. We present the recently published observational SSI composite data set that is based on 20 instruments and has been built by using probabilistic approach that takes into account the scale-dependent uncertainty of each available SSI observation. We compare the variability of this new composite with available SSI reconstructions and discuss the respective modeled responses in the Earth's atmosphere. Also, future work to further improve the dataset are discussed

A new observational solar spectral irradiance composite

International audienceVariations in the solar spectral irradiance (SSI) are an important driver of the chemistry, temperature, and dynamics of the Earth's atmosphere and ultimately the Earth's climate. To investigate the detailed response of the Earth's atmosphere to SSI variations, a reliable SSI data set is needed. We present the recently published observational SSI composite data set that is based on 20 instruments and has been built by using probabilistic approach that takes into account the scale-dependent uncertainty of each available SSI observation. We compare the variability of this new composite with available SSI reconstructions and discuss the respective modeled responses in the Earth's atmosphere. Also, future work to further improve the dataset are discussed

A new observational solar irradiance composite

International audienceVariations of the spectral solar irradiance (SSI) are an important driver for the chemistry, temperature and dynamics of the Earth's atmosphere and ultimately the Earth's climate. Due to the sparce and scattered SSI data sets it is important to establish tools to derive a consistent SSI dataset, including realistic uncertainties. We present the a new SSI composite based on the face values of SSI observations and applying a probabilistic method that takes into account the uncertainty of the data set scale-wise. We will present the data set and discuss its effects on the Earth's atmosphere in relation to SSI reconstruction models

SOLID - a European FP7 project towards the first European comprehensive solar irradiance data exploitation

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