Energy and Water Cycles in the Climate System

Water is the most effective agent in the climate system to modulate energy transfer by radiative processes, through its exchanges of latent heat and within cascades of chemical processes. It is the source of all life on earth, and once convective clouds are formed, it enables the vertical transport of momentum, heat and various atmospheric constituents. Water triggers very complex processes at the Earth’s continental surfaces and within the oceans. Furthermore, water in its gaseous phase is the most important greenhouse gas. Numerical modelling and measurements of the state of the climate system are necessary for a thorough understanding of all these processes and their various interactions and forces. In 1988 the new programme GEWEX (Global Energy and Water Cycle Experiment) was established by the management of the World Climate Research Programme. This programme was specifically defined to determine the energy and water transport in the fast components of the climate system with the presently available means of modelling and measurement and to provide new possebilities for the future. This book describes all aspects of GEWEX.