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Über dieses Buch

This book investigates elementary processes in the Earth’s atmosphere involving photons, electrons, ions, radicals, and aerosols. It is based on global atmospheric models such as the standard atmospheric model with averaged atmospheric parameters across the globe and over time, the Earth’s energetic balance, and the global electric circuit that allows to analyze fundamental atmospheric properties to be analyzed. Rate constants of elementary processes in the Earth’s atmosphere, together with measured atmospheric parameters and existing concepts of atmospheric phenomena, are used in the analysis of global and local atmospheric processes. Atmospheric photoprocesses result from the interaction of solar radiation with the atmosphere and processes involving ions, oxygen atoms, excited atomic particles and ozone molecules. Atmospheric electricity as a secondary phenomenon to atmospheric water circulation results in a chain of processes that begins with collisions of water aerosols in different aggregate states. Cosmic rays are of importance for atmospheric electricity, as they create positive and negative ions in the air. Air breakdown in an electric field of clouds in the form of lightning may develop under the influence of cosmic ray-created seed electrons, which are necessary for electron multiplication in ionization wave-streamers. The upper atmosphere (ionosphere) is formed under solar radiation in a vacuum ultraviolet spectrum, and absorption of this radiation leads to air photoionization. The greenhouse effect is determined by atmospheric water, whereas transitions between a water vapor and aerosols may lead to a change in atmospheric optical depth. Carbon dioxide contributes in small portions to the atmospheric greenhouse effect. Cosmic rays are of importance for atmospheric discharge, the origin of lightning and cloud formation in the first stage of aerosol growth. This book provides a qualitative description of atmospheric properties and phenomena based on elementary processes and simple models.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
The goal of this book is the analysis of some aspects of atmospheric physics and chemistry on the basis of elementary processes in the Earth’s atmosphere, as well as global atmospheric properties and phenomena that are based on these processes. This book has common features with Capitelli et al. (Plasma Kinetics in Atmospheric Gases, 2000 [1]) for the kinetics of excited air.
Boris M. Smirnov

Fundamentals of Atmosphere and Atmospheric Processes

Frontmatter

Chapter 2. Properties of Neutral Atmosphere

Abstract
Some atmospheric parameters as a function of altitude are represented for the atmospheric standard model that operates with averaging over time and season parameters at the latitude of \(45^\circ N\). As a result of air circulation due to air convective motion, molecules and small aerosols are captured by vortices, and their concentration in air does not vary with altitude, whereas micron-size aerosols do not penetrate altitudes above those of their formation. Therefore concentration of water molecules in the stratosphere is small compared to that in the troposphere. The water and carbon balances in the atmosphere are analyzed, and accumulation of \(CO_2\) in the atmosphere is considered from various standpoints. The atmospheric energetic balance of the Earth and its atmosphere is represented and is compared with energetics of other processes.
Boris M. Smirnov

Chapter 3. Charged Particles in Atmosphere

Abstract
Electrons and ions are present in the atmosphere and determine its conductivities at various altitudes. A negative charge of the atmosphere at altitudes below approximately 70 km comes from negative ions, whereas electrons are present at higher altitudes. Mobilities of various positive and negative ions at atmospheric pressure and room temperature are close to \(2\,\mathrm{cm}^2/(\mathrm{V}\cdot \mathrm{s})\). Complex ions are formed at altitudes below \(100\,\mathrm{km}\); the type of ion depends on the altitude and local impurities. Collisions of two neutral aerosols in different aggregate states lead to their charging, and formation of an atmospheric charge is determined mostly by collisions of graupels and ice particles. Along with this, cosmic rays ionize air in the troposphere and stratosphere. Motion of these ions under the action of the Earth’s electric field determines the discharging of the Earth.
Boris M. Smirnov

Chapter 4. Electric Processes in Atmosphere

Abstract
The global electric circuit of the Earth’s atmosphere may be modeled by a spherical capacitor whose low electrode is the Earth’s surface charged negatively and the positively charged upper electrode is located at an altitude of a few kilometers. The atmospheric conductivity increases with an increasing altitude. The air is charging as a result of precipitation of charged aerosols and by lightning which are distributed nonuniformly over the globe. The power of atmospheric electricity is five to six orders of magnitude less than that due to water evaporation and circulation. Cosmic rays are responsible for air ionization with formation of molecular ions in the troposphere. Global powers of some atmospheric processes are compared with those of electrical processes. Three types of ionization waves propagate through the atmosphere under the action of an electric field—an electron avalanche, streamer, and leader—and when a leader creates a conductive channel between a cloud and Earth, a charge is transferred through this channel from a cloud to Earth. Subsequently a transferred charge propagates underground and may cause destruction.
Boris M. Smirnov

Elementary and Transport Atmospheric Processes

Frontmatter

Chapter 5. Electron Processes in Atmospheric Air

Abstract
Elementary processes in atmospheric air are responsible for atmospheric properties at various altitudes, especially for ionosphere properties. Electron processes in atmospheric air are analyzed and include electron attachment to the oxygen molecule and dissociative recombination with molecular ions of air. An equilibrium between electrons and negative or positive ions in hot air is considered. Some aspects of leader propagation in atmospheric air are analyzed.
Boris M. Smirnov

Chapter 6. Ion Processes in Atmospheric Air

Abstract
Elementary processes involving molecular ions in atmospheric air are considered and include charge exchange processes, ion-molecular reactions, associative ionization, and formation of cluster ions. Molecular ions in the troposphere are formed under the action of cosmic rays, move due to air convection and are destroyed in ion-ion recombination collisions in a dry atmosphere or attach to aerosols in clouds. From detection of atmospheric ions and this analysis it follows that cosmic rays penetrate in all atmospheric layers. The number densities of ions located at different layers are determined by rates of corresponding elementary processes. An equilibrium between molecular ions and charged aerosols is analyzed in a cloud that is neutral on average.
Boris M. Smirnov

Chapter 7. Processes in Dissociated Air

Abstract
Atmospheric air is dissociated both at high altitudes and during propagation of lightning current through air. Various aspects of atmospheric dissociated air are analyzed. A conducted expanded lightning channel contains a hot almost equilibrium plasma. The analysis is represented for various channels in the lightning energetic balance. Processes involving atomic oxygen and ozone in excited air are considered.
Boris M. Smirnov

Chapter 8. Atmospheric Processes Involving Aerosols

Abstract
It is shown that the mechanism of gravitation coagulation of aerosols due to different fall velocities is responsible for growth of charged aerosols and creation of electric currents in the atmosphere. Charging of aerosols results from collisions of water aerosols in different aggregate states, mostly graupels and ice particles. From the analysis of processes involving aerosols and observation data it follows that the average charge of aerosols is \(Z = (25-30) e\). Electric fields occur in the troposphere because falling velocities of positively and negatively charged aerosols are different. Charged aerosols of a cloud are located in a plasma that is formed under the action of cosmic rays and prevents clouds from expansion. Fluxes of wet hot air from Earth to clouds which are a precursor of thunderstorms cannot increase the aerosol mass remarkably because of heat processes. Removing a charge from aerosols accelerates their growth and causes rain. In prethunderstorm weather the low edge of a cumulus cloud contains charged aerosols, and there is a negative charge of a lower density of molecular negative ions that are located between a cloud and Earth.
Boris M. Smirnov

Radiative Processes in the Earth Atmosphere

Frontmatter

Chapter 9. Photoionization of Atmospheric Processes

Abstract
The relation is obtained between the cross sections of photoprocesses and the altitude where corresponding photons penetrate. Parameters of photoprocesses involving vacuum ultraviolet photons and oxygen atmospheric components (\(O,\, O_2,\, O_3\)) are represented. The penetration depth for a photon of a given frequency is determined on the basis of the absorption cross section of corresponding processes. General principles of air ionization in the Earth’s atmosphere under the action of solar radiation are analyzed. Penetration of X-rays from solar corona in the Earth’s atmosphere is considered as a possible channel of the ionization process under cosmic rays.
Boris M. Smirnov

Chapter 10. Infrared Atmospheric Emission

Abstract
Emission of a flat layer, consisting of a gas with a weakly varied temperature in the perpendicular direction to the layer, is reduced to the case of the layer with a constant temperature. The average optical thickness of the Earth’s atmosphere in an infrared spectrum range is \(u\approx 2.7\) and is determined on the basis of the energetic balance of the Earth and its atmosphere within the framework of the standard atmosphere model due to emission and surviving of infrared photons. It is shown that infrared emission of the atmosphere is determined mostly by atmospheric water. One can separate the flux of outgoing infrared radiation of the atmosphere from that towards the Earth. The fluxes due to rotation-vibration transitions of atmospheric \(CO_2\) molecules are evaluated. Doubling of the concentration of \(CO_2\) molecules in the atmosphere that is expected over 130 years leads to an increase of the average Earth temperature by \((0.4 \pm 0.2) \) K mostly due to the flux towards the Earth if other atmospheric parameters are not varied. Various models with a water change give the temperature change \((3.0\pm 1.5) \) K at doubling of the \(CO_2\) molecule concentration. An observed temperature change (\(0.8\,^{\circ }\mathrm{C}\)) during the industrial epoch may be realized if approximately \(0.5\,\%\) of free water molecules become aerosols, and this testifies to an atmospheric instability.
Boris M. Smirnov

Chapter 11. Local Atmospheric Photoprocesses

Abstract
Recombination radiation and bremsstrahlung are evaluated for a conductive lightning channel contained an air plasma. Reflection of radio waves and their absorption as a result of interaction with ionospheric layers are analyzed. Photoionization processes are considered which are responsible for propagation of the ionization wave. Luminous phenomena are represented in an upper atmosphere at altitudes below 100 km which develop under the action of the Earth electric field.
Boris M. Smirnov

Chapter 12. Conclusion

Abstract
To sum up the above analysis, we note two principles of this consideration: the first is a detailed analysis of elementary processes in atmospheric air involving electrons, ions, atoms, and aerosols. In particular, one can emphasize that the ionosphere physics was created in the middle of the twentieth century as a result of measurements of the rate constants of appropriate elementary processes.
Boris M. Smirnov

Backmatter

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