Land Surface Evaporation

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.

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.

General circulation models (GCMs) predict certain changes in the amounts and distribution of precipitation, but the conversion of these predictions of impacts on water resources presents novel problems in hydrologic modeling, particularly with regard to the scale of the processes involved. Therefore improved, distributed GCMs are required. New remote sensing technologies provide the necessary spatially distributed data. However, there are many attendant problems with the translation of remotely sensed signals into hydrologically relevant information. This book elucidates how to improve the representation of land surface hydrologic processes in GCMs and in regional and global scale climate studies. It is divided into five sections: Models and Data; Precipitation; Soil Moisture; Evapotranspiration; Runoff.

Water at the Surface of the Earth: An Introduction to Ecosystem Hydrodynamics provides an introduction to the ways in which biological, physical, cultural, and urban systems at the surface of the earth operate, with a particular focus on the hydrodynamics of ecosystems, i.e., water and its association with other forms of matter, including pollutants, and with several forms of energy. The chapter sequence in this book follows the downward progress of water from the lower atmosphere, through ecosystems at the earth's surface, through the soil and mantle rock, to the ""waters under the earth."" In other words, the book begins with input of water to ecosystems, then describes how it is processed in these systems, and ends with the liquid water yield from them. The book first discusses storms in the atmosphere. These are systems that convert inflows of water vapor into outflows of raindrops and snowflakes that are precipitated to the underlying surface. This is followed by separate chapters on how water is delivered from the atmosphere to surface ecosystems; water budgets at the surface and in the soil; evaporation from these systems back to the atmosphere; water in the local air and rocks; and horizontal movement of water transformed by ecosystems where the preceding storages and fluxes were located.

Published by the American Geophysical Union as part of the Water Science and Application Series, Volume 3. Land surface hydrology integrates various physical, chemical and biological processes that occur above, on, and below the surface of the Earth. As a result, it is critical to accurately account for land surface processes within predictive models of hydrology, meteorology, and climate. One of our main difficulties, however, concerns the broad range of spatial and temporal scales that characterize land surface hydrological processes. For example, we determine infiltration by pore scale physics, while soil hydraulic conductivity remains a field scale property. Photosynthesis, respiration, and transpiration occur at the leaf scale. Runoff is a catchment scale process, and the variability of groundwater storage is a regional scale issue. Turbulence in land-atmosphere exchanges of heat, moisture, and momentum occur on the order of seconds to minutes, while variations in land surface and air temperatures occur much more gradually: on the order of hours. The persistence of floods and droughts is seasonal to annual, and so is the effect of El Nino on regional hydrology. Long-term climate effects occur much more slowly, on the order of years to decades.

An in-depth overview of the role of the hydrological cycle within the climate system, including climate change impacts on hydrological reserves and fluxes, and the controls of terrestrial hydrology on regional and global climatology. Table of contents : 1. The Role of the Hydrological Cycle in the Climate System 2. Evaporation 3. Physics of Evaporation and Atmospheric Boundary Layers Over Land 4. Precipitation Physics and Rainfall Observation 5. Land Surface Hydrology 6. Land Surface Schemes and Climate Models 7. Arctic and Snow Hydrology 8. Dynamics of Glaciers, Ice Sheets and Global Sea Level 9. Feedback Mechanisms : Precipitation and Soil Moisture 10. Feedback Mechanisms : Land Use, Hydrology and Carbon 11. Palaeohydrology : An Introduction 12. Groundwater Palaeohydrology 13. Global Warming and the Acceleration of the Hydrological Cycle 14. Climate Change and Hydrological Impact Studies 15. Remote Sensing for Hydrological Studies