Comparison of Forest Water and Energy Exchange Models
Comparison of Forest Water and Energy Exchange Models

Author: S Halldin

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 273

ISBN-13: 0444601724

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Comparison of Forest Water and Energy Exchange Models includes results of comparisons and tests on micrometeorological and hydrological models against independent field data gathered from an International Union of Forestry Research Organizations workshop. The comparisons are made using the SWECON computer by means of the ECODATA program package and the SIMP simulation package. This book is divided into four sections, covering data and computer facilities; atmospheric exchange and radiation models; soil water and interception models; and comparison of models. The first part includes discussion on the climatic data and databases; evapotranspiration measurements; instrumentation; data gathering and processing; the storage, retrieval and analysis of continuously recorded ecosystems data; and the SIMP-interactive mini-computer package for simulating dynamic and static models. The second part presents the MICROWEATHER simulation model that is applied to a forest; the energy exchange model of a pine forest canopy; the simulation of the quality and quantity of short-wave radiation within and above canopies; and the physical model to simulate energy exchange of plant canopies. The third part offers the model HEJMDAL, which simulates water state and flow in the soil-plant-atmosphere system; the water regime of forests and meadow model; the annual energy and water flow in a layered soil model; and the model ETFOREST for the calculation of the actual evapotranspiration. The last section presents a comparison of radiation models, energy exchange models, and interception models.

Variations in the Global Water Budget
Variations in the Global Water Budget

Author: F.A. Street-Perrott

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 521

ISBN-13: 9400969546

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R.E. Newell President, International Commission on Climate International Association of Meteorology and Atmospheric Physics Water is the active ingredient in the global climatic system, its physical properties ensuring that it plays a major role. Its high thermal capacity provides a mechanism for moderating mid latitude winter temperatures; solar energy is absorbed by the surface layers of the middle latitude oceans in summer and is released to the atmosphere in winter as the ocean cools. The variation of saturation vapour pressure with temperature is the factor which causes oceanic surface temperatures at low latitudes to be limited by evaporation to values near 29°C, thereby limiting tropical marine air temperatures to about the same value. The substantial amount of energy involved in phase changes - the latent heat - governs the passage of solar energy to the atmo sphere; visible solar radiation is absorbed at the Earth's surface, energy is supplied to evaporate water and the latent heat is released to the atmosphere when and where condensation occurs, which is often a considerable distance from the source of the moisture. The infrared radiative characteristics of water vapour, namely the broad vibration-rotation bands typical of a triatomic molecule, permit it to act as the principal agent of energy loss from the atmosphere, throu?,h infrared radiation to space.

The Forest-Atmosphere Interaction
The Forest-Atmosphere Interaction

Author: B.A. Hutchison

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 683

ISBN-13: 9400953054

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The effects of meteorological phenomena upon forest produc tivity and forestry operations have been of concern for many years. With the evolution of system-level studies of forest eco system structure and function in the International Biological Program and elsewhere, more fundamental interactions between forest ecosystems and the atmosphere received scientific atten tion but the emphasis on meteorological and climatological effects on forest processes remained. More recently, as recogni tion has developed of potential and actual problems associated with the atmospheric transport, dispersion, and deposition of airborne pollutants, the effects of forest canopies upon boundary-layer meteorological phenomena has come under scientific scrutiny. Looking to the future, with rising atmospheric con centrations of C02 and increasing competition for the finite fresh-water resources of the earth, interest in the role of forests in global C02 and water balances can also be expected to intensify. Thus, the nature of forest canopy-atmosphere interac tions, that is to say, the meteorological phenomena occurring in and above forest canopies, are of importance to a wide variety of scientific and social-issues. Demands for forest meteorological information currently exceed levels of knowledge and given the economic constraints of science in general and environmental sciences in particular, chances for major improvements in scien tific support in the near future are slim. Unfortunately, studies of environmental phenomena in and above forests are costly and logistically difficult. Trees, the ecological dominants of forest ecosystems, are the largest of all terrestrial organisms.

Subsurface Hydrological Responses to Land Cover and Land Use Changes
Subsurface Hydrological Responses to Land Cover and Land Use Changes

Author: Makoto Taniguchi

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 232

ISBN-13: 1461561418

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Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.