Land Surface Hydrology Meteorology And Climate

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.

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.

This 1982 book consists of papers presented at the World Climate Research Programme study conference on land surface processes held in Greenbelt, Maryland from 5 to 10 January 1981. The papers cover the following: the state of knowledge of the sensitivity of atmospheric general circulation models on hydrology and other land surface processes: assessment of the state of knowledge of numerical modelling of hydrology and other land surface processes at the scale of atmospheric general circulation models; recommendations for research activities; establishment of data requirements for initialization, validation, and parameter evaluation. This book will continue to be of interest to atmospheric scientists, soil physicists, hydrologists and climatologists.

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

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.

The continental hydrological cycle is one of the least understood components of the climate system. The understanding of the different processes involved is important in the fields of hydrology and meteorology. In this volume the main applications for continental hydrology are presented, including the characterization of the states of continental surfaces (water state, snow cover, etc.) using active and passive remote sensing, monitoring the Antarctic ice sheet and land water surface heights using radar altimetry, the characterization of redistributions of water masses using the GRACE mission, the potential of GNSS-R technology in hydrology, and remote sensing data assimilation in hydrological models. This book, part of a set of six volumes, has been produced by scientists who are internationally renowned in their fields. It is addressed to students (engineers, Masters, PhD) , engineers and scientists, specialists in remote sensing applied to hydrology. Through this pedagogical work, the authors contribute to breaking down the barriers that hinder the use of Earth observation data. Provides clear and concise descriptions of modern remote sensing methods Explores the most current remote sensing techniques with physical aspects of the measurement (theory) and their applications Provides chapters on physical principles, measurement, and data processing for each technique described Describes optical remote sensing technology, including a description of acquisition systems and measurement corrections to be made

Our views and understanding of variations in climate, geomorphological processes and the interrelationships that exist between climatic changes and land surface changes, both now and in the past, have developed greatly over the last decade. This book aims to encapsulate some of these recent advances and focuses on the integration of research that has been conducted by geomorphologists and climatologists on linking climate and land surface changes. This book is divided into two main parts: Section A incorporates research that has concentrated on short-term variations in climate, whilst Section B looks at some of the work on long-term climate variability. The volume concludes with a summary chapter that brings together the various ideas that have been presented in this work and other recent research in this general field. This text will be of interest to upper level students of geomorphology, Quaternary studies, climatology, earth sciences, and environmental studies. It will also be of use to researchers in these fields.