GACP Projects
Surface Solar Radiation Data Base
George Kukla, PI
Beate G. Liepert, Co-I
Abstract: The main goal of the proposed work is to address the variability of the direct and indirect aerosol effect for the past three decades. Our approach is indirectly by analyzing existing high-quality records of broad band solar radiation measurements worldwide.
In the first step, a data base of hourly surface solar radiation will be developed for clear, partly cloudy, overcast sky conditions (already exists for Germany and the US). The clear sky records will be stratified by solar zenith angle categories. Surface solar radiation climatologies will be calculated for these cloud cover conditions and for various "event strategies". The design of the data base will be flexible for future needs. Changes over time of the direct aerosol radiative forcing will be addressed with clear sky climatologies (Kukla/Liepert 1997) and changes over time of the indirect aerosol effect will be analyzed with overcast sky climatologies (Liepert 1997).
In the second step, comparisons with satellite derived determinations and modeling results will be carried out (Wild/Liepert 1998). Finally the candidate aerosol and aerosol forcing climatologies derived from satellite observations and model calculations will be validated with the surface climatologies and the uncertainties will be quantified. Together with improved satellite retrievals and model calculations the proposed work will enable more realistic aerosol climatologies which are needed for global climate change studies.
Planned input:
Climatologies of modelled and satellite derived clear sky and overcast surface solar radiation fluxes for various aerosol climatologies.
Planned output:
Long term time series of surface solar radiation of clear sky and overcast conditions for selected stations worldwide.
