It is well known that the interactions between land surfaces and the atmosphere, and the resulting exchanges in water and energy have a tremendous affect on climate. The inadequate representation of land-atmosphere interactions is a major weakness in current climate models, and is providing the motivation for the HAPEX and ISLSCP experiments as well as the proposed Global Energy and Water Experiment (GEWEX) and the Earth Observing System (EOS) mission. The inadequate representation reflects the recognition that the well-known phys ical relationships, which are well described at small scales, result in different relationships when represented at the scales used in climate models. Understanding this transition in the mathematical relationships with increased space-time scales appears to be very difficult, and has led to different approaches; at one extreme, the famous "bucket" model where the land-surface is a simple one layer storage without vegetation; the other extreme may be Seller's Simple Biosphere Model (Sib) where one big leaf covers the climate model grid. Given the heterogeneous nature of landforms, soils and vegetation within a climate model grid, the development of new land surface parameterizations, and their verification through large scale experiments is perceived to be a challenging area of research for the hydrology and meteorology communities. This book evolved from a workshop held at Princeton University to explore the status of land surface parameterizations within climate models, and how observa tional data can be used to assess these parameterizations and improve models.

Provides an essential introduction to modeling terrestrial ecosystems in Earth system models for graduate students and researchers.

General circulation model (GCM) experiments in the late 1970's indicated that the climate is sensitive to variations in evaporation at the land surface. Thus, in the context of climate modeling, it became important to develop techniques which would realistically estimate the evaporation flux on land. Land Surface Evaporation: Measurement and Parameterization discusses strategies for the use of experimental data in developing and testing parameterization schemes of the evaporation flux in GCM's. The book reviews state-of-the-art techniques, such as remote sensing, which measure evaporation fluxes over continental surfaces. It evaluates their relevance with respect to the various spatial and temporal scales of interest. This book will provide researchers in climatology, meteorology, hydrology and water management, and remote sensing with a thorough overview of current research in land surface evaporation. It will also give young scientists insight into surface processes.