scholarly journals Using stellar scintillation for studies of turbulence in the Earth’s atmosphere

Author(s):  
V. F. Sofieva ◽  
F. Dalaudier ◽  
J. Vernin

Stellar scintillation observed through the Earth's atmosphere is the result of interaction of light waves and the turbulent atmosphere. This review is dedicated to using stellar scintillation measurements for studies of turbulence in the Earth's atmosphere. We present an overview of ground-based, air-borne and satellite stellar scintillation measurements, discuss the approaches to data analyses and give an overview of the main geophysical results. We also discuss the benefits of the scintillation method in studies of the structure of air density irregularities and its limitations.

Author(s):  
C. David Whiteman

The earth's atmosphere is divided into four layers: the troposphere, stratosphere, mesosphere, and thermosphere (figure 4.1). These layers are defined by alternating decreases and increases in air temperature with height. The boundaries between the layers are called the tropopause, stratopause, and mesopause. The troposphere, the lowest layer of the atmosphere, supports life on the planet and is the layer in which “weather” occurs. It extends about 7 mi (11 km) above sea level and is characterized by a mean temperature decrease with height (—ΔT/ Δz) of about 3.5°F per 1000 ft, or 6.5°C per km. This decrease explains the lower temperatures encountered at higher elevations in the mountains. Although the mean temperature decreases with height in the troposphere, the atmospheric structure, particularly at the base of the troposphere, varies significantly over time as the earth warms during the day and cools at night, as the seasons change, and as weather systems move through the atmosphere. The vertical structure of the atmosphere is characterized by an exponential decrease in air density and pressure with height. Air density is the mass per unit volume of the atmosphere as expressed, for example, in kilograms per cubic meter or pounds per cubic foot. Air pressure is the force exerted on a unit area by the weight of the air molecules above the measurement point as expressed, for example, in millibars or pounds per square inch. Air pressure at any given level is thus a measurement of the weight of a column of air above that level. Although there is no "edge" to the earth's atmosphere, approximately 99.9% of the air molecules (and therefore the weight of the atmosphere) are found below 31 mi (50 km). Temperature, density, and pressure are interrelated, so that a change in one will result in changes in the other two. The mathematical description of this relationship is called the gas law (appendix A). The gas law allows any one of these variables to be calculated if values for the other two variables are known.


Author(s):  
Michael I. Budyko ◽  
Alexander B. Ronov ◽  
Alexander L. Yanshin

Author(s):  
A. NIKOLAYEV ◽  
◽  
A. M. Mebel ◽  
V. N. Azyazov ◽  
◽  
...  

This research is devoted to the problem of environmental pollution. The study of various pathways that reduce emissions of fuel combustion products into the Earth's atmosphere is still applicable today.


Author(s):  
E. L. Wolf

This is a physics textbook describing, at a college level, the physics and technology needed to provide sustainable long-term energy, past the era of fossil fuels. A summary is given of global power generation and consumption, with estimates of times until conventional fuels will deplete. Sustainable power sources, largely those coming from the Sun directly or indirectly, are described. As sustainable energy must preserve the Earth’s atmosphere and climate, key elements of these topics are included. Key energy technologies in this book include photovoltaics, wind turbines and the electric power grid, for which the underlying physics is developed. Nuclear fusion is described in the context of the Sun’s energy generation, in a brief description of tokamak fusion reactors, and also to introduce ideas of quantum physics needed for adequate treatment of photovoltaic devices. Energy flow in and out of the Earth’s atmosphere is discussed, including the role of greenhouse gas impurities arising from fossil fuel burning as trapping heat and raising the Earth’s temperature. Discussion is included of the Earth’s climatic history and future. Exercises are included for each chapter.


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