Weathering dynamics

In short, much future research on kinetics of soil chemical processes is needed. Areas worthy of investigation include improved methodologies, increased use of spectroscopic and rapid kinetic techniques to determine mechanisms of reactions on soils and soil constituents, kinetic modeling, kinetics of anion reactions, redox and weathering dynamics, kinetics of ternary exchange phenomena, and rates of organic pollutant reactions in soils and sediments. 

If hydrogen makes subsonic planes look good, its use in a future supersonic transport (SST) glows with economic promise and environmental health, although studies are still needed to determine whether and how increased water vapor (in itself harmless) might change weather dynamics in the high stratosphere. 

Dynamic meteorological models, much like air pollution models, strive to describe the physics and thermodynamics of atmospheric motions as accurately as is feasible. Besides being used in conjunction with air quaHty models, they ate also used for weather forecasting. Like air quaHty models, dynamic meteorological models solve a set of partial differential equations (also called primitive equations). This set of equations, which ate fundamental to the fluid mechanics of the atmosphere, ate referred to as the Navier-Stokes equations, and describe the conservation of mass and momentum. They ate combined with equations describing energy conservation and thermodynamics in a moving fluid (72) ... 

In thermal building-dynamics simulation codes, outdoor conditions are mostly input by the so-called weather data file, containing (usually hourly) data for air temperature, wind speed and direction, air humidity, and global and diffuse solar radiation on horizontal surfaces. 

In order to run a dynamic simulation, weather data files are needed, providing (usually hourly) data on the following quantities air temperature, air humidity, ground temperature, global and diffuse irradiation on horizontal surfaces, and wind speed and direction. 

Our understanding of seasonal and interannual variation in global terrestrial vegetation dynamics is, however, very sketchy at present. Ecosystem respiration measurements have been made for various soil-vegetation types for variable lengths of time Relationships between ecosystem respiration and weather data have been derived from these data for four major biomes 88), However, additional systematic collection of field respiration measurements would be necessary for placing much confidence in such a relationship. 

For soil profiles that are less than the optimum thickness, there is a destabilizing feedback between soil thickness and weathering rate. Assume that a thin soil is in a dynamic equilibrium such that weathering inputs balance transport losses (A in Fig. 9-3). Weathering rate... 

Why are the oceans so depleted in these trace metals Certainly it is not for the lack of availability from rock weathering or because of constraints imposed by the solubility of any unique compound of these elements. The reason must lie in the dynamics of the system of delivery of the metals to the oceans and their subsequent behavior in an ocean that cannot be simulated by simple in vitro experiments involving homogeneous reaction kinetics. 

According to Cairns-Smith, the first primitive gene materials could have been clay minerals these crystallize out everywhere on Earth from dilute silica solutions and hydrated solutions of metal ions. Both groups of substances are continually being formed by weathering processes. Two cycles keep this dynamic process going ... 

Microbial Mediation of Weathering Transformation of Soil Minerals and Metal Dynamics... 

The mass balance model for calculation of critical loads for heavy metals includes the weathering process, the net removal through the crop biomass harvest, leaching, and also leaf uptake and litterfall. Using the simple dynamic way, the distribution between adsorbed and dissolved phases was accounted. 

Exterior spoilers, trims, lighting seals, mirror gaskets, dynamic and static weather seals... 

A continuous, dynamic, one-dlmenslonal model called the Pesticide Root Zone Model or PRZM, has been developed recently by EPA/ORD In Athens, Georgia (110). PRZM allows for varying hydrologic and chemical properties by soil horizon. Weather data for water flow modeling Is obtained from dally precipitation records of the National Weather Service. It has been successfully validated with atrazlne field data from Watklns-vllle, Georgia and aldlcarb data from Long Island, New York for depths less than 3 meters. 

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