M.Sc. (Physics) curriculum, Tribhuvan University 2073

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PHY613: Atmospheric Physics I 2 CH (L30+T10) Nature of the course: Theory Full Marks: 50 Pass Marks: 25

Course Description: The course aims to provide the knowledge and to prepare students for the higher studies and research in the field of atmospheric physics. The course is designed with the following objectives.

Course objective:

To provide a broad knowledge of atmospheric physics.

To prepare students to explore contemporary issues of atmospheric phenomena.

To develop skills to observed and to find the solutions to the atmospheric problems. Course Contents: 1. The Earth atmosphere: [2 hours]

1.1 Scope, definitions and terms of reference, 1.2 Optical properties of the atmosphere, 1.3 Structureand chemical composition of the atmosphere.

2. Atmospheric thermodynamics: [8 hours]

2.1 Gas laws, 2.2 Virtual temperature, 2.3 Hydrostatic equation, 2.4 The first law of thermodynamics, 2.5 Adiabatic processes, 2.6 Water vapor in air, 2.7 Atmospheric stability, 2.8 Thermodynamic diagram: SkewT-lnP diagram and its applications.

3. Absorption and scattering of solar radiation: [8 hours]

3.1 Solar and terrestrial radiation, 3.2 Radiation spectrum and quantitative description, 3.3 Solar constant and insolation outside the atmosphere, 3.4 Physics of scattering, absorption and emission, 3.5 Broadening of absorption lines, 3.6 Computation of solar heating rates, 3.7 Representation of polarized light and Stokes parameter, 3.8 Rayleigh scattering: theoretical development.

4. The ionosphere: [6 hours]

4.1 Formation and nature of ionosphere layers, 4.2 Diffusive equilibrium, 4.3 Chapman’s theory of a production layer, 4.4 Rate of production of ions, 4.5 Peak electron concentration, 4.6 Determination of number density of electrons, 4.7 Transmission of radio waves.

M.Sc. (Physics) curriculum, Tribhuvan University 2073

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5. Radiative transfer in the atmosphere: [8 hours] 5.1 Thermal infrared spectrum and atmospheric effect, 5.2 The equation of radiative transfer, 5.3 Beer’s law, 5.4 Schwarzschild’s equation, 5.5 The plane-parallel approximation, 5.6 Infrared transfer in plane-parallel atmosphere, 5.7 Concept of transmission function, 5.8 Band models: single spectra line, regular band model, statistical band model, Curtis-

Godson approximation.

Text Books:

1. Wallace J. M. and Hobbs P. V. – Atmospheric Science, International Geophysics Series, Elsevier Inc. (2006).

2. Liou K. N. – An Introduction to Atmospheric Radiation, Academic Press Inc., New York (1980).

Reference Books:

1. Salby M. L. – Fundamentals of Atmospheric Physics Academic Press, New York (1996). 2. Seinfeld J. H. and Pandits S. N.– Atmospheric Chemistry and Physics, John Wiley & Sons,

Inc., New York (1998). 3. Ratcliffe J. A. – An Introduction to the Ionosphere and Magnetosphere, Cambridge

University Press (1972).