Physical Basis of Remote Methods of Atmospheric SoundingBachelor's program
Volume: 32 hours
PROGRAM CONTENT
1. Introduction
Direct and inverse problems of mathematical physics. Examples of inverse problems in different science fields. Direct and inverse problems of atmospheric optics. Different types of inverse problems of atmospheric optics.
Remote methods for measuring the atmospheric parameters. Classification of remote methods by different distinctions. Block-scheme of remote measurements.
Significance of a priori information for solving the inverse problems of atmospheric optics. Radiation and radiation-physical inverse problems of atmospheric optics.
Advantages and shortcomings of remote methods. History of developing the remote methods.
2. Transmittance methods
Physics-mathematical model of remote measurements based on the registration of solar radiation attenuation. Different measurement geometry. Application of the Moon and star radiation.
Ground-based measurement methods. Determination of atmospheric optical depth. Methods of separating the optical depths of different physical nature. Long and short Bouguer's methods. Factors determining the accuracy of Bouguer's methods.
Determination of characteristics of atmospheric gaseous content. Absorption bands of atmospheric gases in different spectral ranges.
Special features of remote methods of measuring the characteristics of atmospheric gaseous content in UV, visible and IR spectral ranges. Analysis of an accuracy of methods. Consideration of instrument characteristics in atmospheric remote sounding.
Determination of total ozone content (TOC) - Dobson and Guschin methods. Instruments for determining the TOC. Analysis of the accuracy of remote measurements.
Retrieval of characteristics of atmospheric gaseous content from atmospheric transmittance measurements in IR spectral range. Model of a real experiment. Methods for analyzing the data. Factors determining the accuracy of remote method.
Possibilities of ground-based measurements of vertical profiles of absorbing gases.
Determination of optical and micro-physical characteristics of atmospheric aerosol and clouds.
Satellite transmittance methods - advantages and shortcomings of the satellite method.
Methods of separating the atmospheric optical depth into different components. Algorithms of interpreting the measurement data. Analysis of factors determining the accuracy of a method. Examples and results of satellite experiments. Retrieval of characteristics of aerosol and gaseous atmospheric content.
Methods of retrieving the vertical profiles of atmospheric density and temperature. Application of star radiation - peculiarities of this method.
3. Thermal radiation methods
Formulation of physics-mathematical model of remote measurements. Motivation of used simplifications.
Absorption spectrum of the atmosphere in IR and microwave spectral ranges. Analysis of advantages of different spectral ranges.
Determination of the temperature of underlying surfaces. Emissivities of different underlying surfaces in atmospheric spectral windows. Factors determining the accuracy of measuring the temperature of underlying surfaces - errors of measuring the outgoing radiation, atmospheric influence, variations of emissivity of underlying surfaces. Methods for determining the land temperature.
Methods of taking the atmospheric influence into account in determination of underlying surface temperature. Transfer function of the atmosphere. Two-wave ( two-angle ) method. Complex solution of the problem.
Determination of the altitude of high bound of clouds.
Determination of vertical profile of atmospheric temperature. Formulation of the inverse problem. Spectral and angular methods of temperature sounding. Advantages and shortcomings of different spectral ranges. Principal factors determining the accuracy of atmospheric temperature sounding. Influence of measurement errors, the accuracy of assigning the atmospheric radiation characteristics, the interpretation method, the vertical resolution, instrument spectral characteristics.
Temperature sounding under condition of cloud atmosphere.
Microwave temperature sounding. Influence of clouds and precipitation. Recent instruments for atmospheric temperature sounding. Problems of estimating the accuracy of atmospheric temperature measurements. Slant path transmittance sounding of atmospheric temperature - advantages and shortcomings of the method.
Temperature sounding of non-LTE atmosphere.
Remote method of retrieving the characteristics of atmospheric gaseous content. Formulation the problem for IR and microwave spectral ranges. Spatial peculiarities of weight functions. Factors which define the accuracy of retrieving the vertical profiles of atmospheric gaseous components.
Retrieval of vertical profiles of the water vapor and the ozone.
Modern satellite instruments for determining the characteristics of atmospheric gaseous content.
Formulation of the problem of retrieving the water vapor total content and cloud water content in microwave spectral range. Determination of precipitate intensity and the velocity near water surface.
Methods of measuring the soil moisture and the wind velocity in atmosphere.
4. Remote methods based on measurements of reflected and scattered solar radiation
Formulation of physics-mathematical model of remote measurements. Single-scattering approach.
Determination of the altitude of cloud upper bound. Influence of the scattering in cloud layer. Recent accuracy of the remote method.
Determination of vertical profile and total content of the ozone. Factors defining the method accuracy. Modern satellite instruments and the real accuracy of the remote method. Determination of ozone trends.
Ground-based method of retrieving the ozone vertical profile and total content. Accuracy and vertical resolution of the method.
Determination of atmospheric aerosol characteristics. Common formulation of the remote measurement method. Influence of a priori information on the accuracy of retrieving the atmospheric aerosol characteristics.
Polarization method of determining the ozone total content and characteristics of atmospheric aerosol state.
Remote methods of measuring the wind field.
Determination of atmospheric trace gases. Examples of satellite and ground-based experiments.
Twilight sounding methods.
5. Remote refractometry
Refraction in planet atmospheres. Peculiarities of the refraction in different spectral ranges. Equation of light ray. Regular and random refraction. Different schemes of refraction measurements. Application of solar and star radiation for sounding the atmosphere. Refraction methods of retrieving the atmospheric density and temperature. Analysis of accuracy of methods.
Application of star scintillations for retrieving the atmospheric parameters.
Space methods of the refractometry. Analysis of the accuracy of retrieving the vertical profiles of temperature and humidity from refraction observations in radio range.
6. Laser (lidar) sounding of atmosphere and underlying surface
Characteristics of recent lasers: continuous and impulse ones, pulse power, frequency, monochromatizm, duration.
Different schemes of lidar observations: monostatical and bistatical schemes, horizontal paths. Principal parts of lidar system.
Common analysis of advantages and shortcomings of laser sounding methods. Equation of laser detection for different types of interaction of radiation with a medium. Applicability of one-scattering approach.
Spatial resolution of lidar sounding - principal determine factors.
Lidar methods for determining the atmospheric density (temperature) based on Rayleigh scattering. Ranges of the method applicability. Errors of determining the density and temperature. Characteristics of modern lidars for sounding the middle atmosphere. Examples of atmospheric density and temperature retrievals.
Lidar methods of retrieving the atmospheric temperature based on Raman scattering.
Lidar methods of retrieving the atmospheric aerosol characteristics. Different methods of assigning the additional information to obtain the unique solution. Multi-spectral method for retrieving the atmospheric aerosol characteristics. Errors of lidar sounding of atmospheric aerosol. Examples of lidar sounding the atmospheric aerosol.
Lidar methods of retrieving the characteristics of atmospheric gaseous content: horizontal path transmittance method, differential absorption method, Raman scattering methods.
Theory of differential absorption method, analysis of errors. Examples of using the method - determination of ozone vertical profile.
Retrievals of characteristics of atmospheric gaseous content from measurements of Raman scattering. Comparison of advantages and shortcomings of different lidar methods for retrieving the characteristics of atmospheric gaseous content.
Determination of cloud characteristics: cloud altitude and extent, phase content. Polarization lidar methods.
Lidar methods of determining the characteristics of underlying surfaces. Sounding of water surfaces and water mediums.
Space lidar methods of sounding the atmosphere and underlying surface.
Peculiarities of space lidar sounding. Examples of satellite experiments.
7. Radar sounding of atmosphere and underlying surface
Physical base of radar detection. Optical characteristics of the atmosphere and clouds in radio range. Radar equation. Effective scattering cross-section for spherical water and ice particles.
Radar determination of cloud altitude. Radar methods of studying the clouds and precipitation Analysis of factors defining the accuracies of the study of cloud water content and precipitation intensity.
Radar methods of sounding the underlying surfaces.
Determination of the wind velocity near water surface.
Space radar observations.
8. Acoustic sounding of the atmosphere
Physical base of remote acoustic methods. Peculiarities of propagation of acoustic waves in atmosphere.
Acoustic methods of sounding the near-ground atmospheric layer.
Radar-acoustic sounding of atmosphere.
9. Conclusion
Global system of monitoring the environmental parameters. Principal problems of the monitoring of environmental parameters. The role of different observation systems in the monitoring. Satellite subsystem of global observations.
Investigation of planet atmospheres.
Opportunities of development of global observation system.
Advisable literature
1. Rozenberg G.V. Twilight. M. Phys-mat. Lit. 1963. 380 pp.
2. Kondratyev, K.Ya. and Yu.M. Timofeyev. Thermal Sounding of the Atmosphere from Satellites. L. Hydrometeoizdat. 1970. 410 pp.
3. Turchin, V.F., V.P. Kozlov, M.S. Malkevich. Application of methods of mathematical statistics for solving the ill-posed problems. Progress in Physical Sciences, 1970, 102, 3, pp.33-55.
4. Malkevich M.S. Optical Atmospheric Investigation from Satellites. M. Nauka. 303 pp.
5. Stepanenko V.D. Radar Observations in Meteorology. L. Hydrometeoizdat. 1973. 343 pp.
6. Basharinov A.E., Gurvich A.S., Egorov S.T. Radio-frequency Radiation of the Earth as a planet. M. Nauka. 1974. 188 pp.
7. Zuev V.E. Laser-meteorologist. L. Hydrometeoizdat. 1974. 179 pp.
8. Zakharov V.M., Kostko O.K. Meteorological Laser Detection. L. Hydrometeoizdat. 1977. 222 pp.
9. Kondratyev, K.Ya. and Yu.M. Timofeyev. Meteorological Sounding of the Atmosphere from Space. L. Hydrometeoizdat.1978. 280 pp.
10. Laser control of the atmosphere. Ed. by E.De Hinkli. M. Mir. 1979. 416 pp.
11. Karol, I.L, V.V. Rozanov, and Yu.M. Timofeyev. Gaseous Admixtures in the Atmosphere. L. Hydrometeoizdat. 1983. 192 pp.
12. Kondratyev K.Ya., V.V. Melentyev. Space Remote Indication of Clouds and Atmospheric Humidity. L. Gidrometeoizdat. 1986. 263 pp.
13. Mejeris R. Laser Remote Sounding. M. Mir. 1987. 550 pp.
14. Stephens G.L. Remote Sensing of the Lower Atmosphere. An Introduction. New York, Oxford. Oxford University Press. 1994. 523 pp.