Science rationale for CAWSES (Climate and Weather of the Sun–Earth System): SCOSTEP’s interdisciplinary program for 2004–2008

An international program called Climate and Weather of the Sun–Earth System (CAWSES) has been developed by the Scientific COmmittee on Solar–TErrestrial Physics (SCOSTEP) for the study of integrated Sun–Earth system science to be conducted over the period 2004–2008. This program aims to significantly enhance our understanding of the space environment and its impacts on life and society. The main functions of CAWSES are: (a) to help coordinate international activities in observations, modeling and theory crucial to achieving this understanding; (b) to encourage involvement of scientists in both developed and developing countries in such efforts; and (c) to provide educational opportunities for students at all levels. Such multi-nation, multi-technique studies are absolutely essential for an understanding of the short term (space weather) and the long term (space climate) variability throughout the entire solar–terrestrial domain, for its societal applications and for tracking global changes in climate and ozone. The CAWSES program has been organized under four science Themes: (i) Solar Influence on Climate; (ii) Space Weather: Science and Applications; (iii) Atmospheric Coupling Processes; (iv) Space Climatology. Progress on some of these Themes can only be achieved through conducting carefully planned experimental campaigns with the data being assimilated in coupled physics based models. An end-to-end modeling capability is the ultimate goal of solar–terrestrial science. We hope these aspects will help us also in our Capacity Building efforts which is the fifth Theme under the CAWSES program – particularly in developing countries. In this paper, we will highlight some of the aspects of CAWSES science and attempt to discuss how different specialities in various research fields can be brought together with a well-defined purpose of understanding the interdependencies of the Sun–Earth system as a single entity.