Earth,Atmospheric, Ocean & Planetary Sciences Paper 2 Meteorology
(i) Climatology: Fundamental principles of climatology; Earth- sun relationship: earth’s radiation balance, latitudinal and seasonal variation of insolation, temperature, humidity, wind and precipitation. Indian climatology with special reference to seasonal distribution and variations of temperature, humidity, wind and precipitation: air masses notably monsoons, and jet streams, tropical cyclones, and cloud formation, classification of climates: Koppen’s and Thornthwaite’s schemes as applicable to India. Climatic zones of India. Hydrological cycle and water balance. Climate change: green house warming, stratospheric ozone depletion. Palaeoclimatology.
(ii) Physical Meteorology: Layered structure of the atmosphere and its composition. Radiation: basic Laws - Raleigh and Mie scattering, multiple scattering, radiation from the sun, solar constant, effect of clouds, surface and planetary albedo. Emission and absorption of terrestrial radiation, radiation windows, radiative transfer, Greenhouse effect, net radiation budget; Derivation of radiance parameters from satellite observations. Thermodynamics of dry and moist air: specific gas constant, Adiabatic and Non adiabatic processes, entropy and enthalphy, Moisture variables, virtual Temperature; Clausius - Clapeyron equation, adiabatic process of a moist air; thermodynamic diagram: Emagram, tephigram, skew T-log p and Stuve diagrams. Hydrostatic equilibrium: Hydrostatic equation, variation of pressure with height, geopotential, standard atmosphere, altimetry. Vertical stability of the atmosphere: Dry and moist air parcel and slice methods, Entrainment, Bubble theory, Diurnal variation of lapse rate, convection in the atmosphere.
(iii) Atmospheric Electricity: Fair weather electric field in the atmosphere and potential gradients, ionisation in the atmosphere, conduction currents, air-earth currents, point discharge currents. Electrical fields in thunderstorms, theories of thunderstorm electrification, lightning discharges.
(iv) Cloud Physics: Cloud classification, condensation nuclie, growth of cloud drops and ice-crystals, precipitation mechanisms: Bergeron, Findeisen process, coalescence process - Precipitation of warm and mixed clouds, artificial precipitation, hail supression, fog and cloud - dissipation, radar observation of clouds and precipitation, radar equation, rain-drop spectra, radar echoes of hail and tornadoes, radar observation of hurricanes, measurements of rainfall by radar.
(v) Dynamical Meteorology: Basic equations and fundamental forces: Pressure gravity, centripetal and coriolis forces, continuity equation in Cartesian and isobaric coordinates. A momentum equation in rotating, cartesian, and spherical coordinates; scale analysis, Inertial flow, Geostrophic and gradient winds, thermal wind. Divergence and vertical motion, Rossby, Richardson, Reynolds and Froude numbers. Circulation vorticity and divergence: Bjerknese circulation theorem and applications, Vorticity and divergence equations, Scale analysis, Potential vorticity, Stream function, velocity potential. Atmospheric turbulence: Mixing length theory, planetary boundary layer equations, surface layer, Ekmann layer, eddy transport of heat, water vapour and momentum, Richardson criterion. Linear perturbation theory: Internal and external gravity waves, Inertia waves, gravity waves, Rossby waves, wave motion in the tropics, barotropic and baroclinic instabilities; Taylor - Goldstein instability; theorems of Mines, Fjortozt, Howard and Pedlosky. Atmospheric energetics: Kinetic, potential and internal energies - Conversion of potential and internal energies into Kinetic energy, available potential energy.
(vi) Numerical Weather Prediction: Computational instability, filtering of sound and gravity waves, filtered forecast equations, barotropic and equivalent barotropic models, two parameter baroclinic model, relaxation method, Two layer primitive equation model; short, medium and long range weather prediction models; objective analysis; Initialisation of the data for use in weather prediction models; data assimilation techniques.
(vii) General Circulation and Climate Modelling: Observed zonally symmetric circulations, meridional circulation models, mean meridional and eddy transport of momentum and energy, angular momentum and energy budgets; zonally asymmetric features of general circulation; standing eddies; east-west circulations in tropics; climate variability and forcings; feedback processes, low frequency variability, ENSO, QBO and sunspot cycles. Basic principles of general circulation modelling; Grid-point and spectral GCMs; role of the ocean in climate modelling; interannual variability of ocean fields (SST, winds, circulation, etc.) and its relationship with monsoon, concepts of ocean - atmosphere coupled models.
(viii) Synoptic Meteorology: Synoptic charts, Weather observations, and transmission. Analysis of surface, upper air and other derivative charts; Stream lines, isotachs and countour analysis; tilt and slope of pressure/weather systems with height. Synoptic weather forecasting, Prediction of Weather elements such as rain, maximum and minimum temperature and fog; hazardous weather elements like thundestorms, duststorms, tornadoes, dates of onset, and withdrawal of monsoons, break monsoon; formation and movement of western disturbances, depressions and tropical cyclones; intensification, weakening, deepening and filling of surface pressure systems. Air masses and fronts: Sources, origin and classification of air masses; classification of fronts, frontogenesis and frontolysis; structure of cold and warm fronts; Weather systems associated with fronts. Extra-tropical synoptic scale features: jet streams, extratropical cyclones; anticyclones and blockings. Tropical synoptic meteorology: Trade wind inversion; ITCZ; monsoon trough; Tropical cyclones, their structure and development theory; Monsoon depressions; tropical easterly jet stream; Somali Jet; Waves in easterlies; western disturbances; SW and NE Monsoons; synoptic features associated with onset, withdrawal, break, active and weak monsoons.
(ix) Aviation Meteorology: Meteorological hazards to aviation; take-off, landing, inflight-icing, turbulence, visibility, fog, clouds, rain, gusts, wind shear and thunderstorms.
(x) Satellite Meteorology: Meteorological satellites: Polar orbitting and geostationary satellites, Visible and infrared radiometers, multiscanner ratiometers; identification of synoptic systems, fog and sandstorms, detection of cyclones, estimation of SST and cloud top temperatures, winds, and rainfall; temperature and humidity soundings.
