Abstract
Numerical experiment with improved boundary layer physics has been performed to study the Planetary Boundary Layer (PBL) characteristics over the monsoon trough region. Details of the evolution and structure of the associated boundary layer processes in the monsoon trough and adjoining oceanic regions are examined by integrating the model up to a period of 48 hours.
The model used for this study is a high resolution primitive equation, one with 0·5o latitude/longitude horizontal resolution and 16 levels in the vertical (7 levels in the PBL). The boundary layer treatment in the model is based on the Monin-Obukhov similarity theory for the surface layer and Turbulent Kinetic Energy (TKE) formulation based onE-ε approach for the mixed layer. The model is integrated using the FGGE level IIIb analysis of European Centre for Medium Range Weather Forecasts (ECMWF), U.K.
The study shows that the diurnal variation of TKE over land is a dominant feature comparing with that over the ocean. Along the monsoon trough region, TKE increases from the eastern end to the western side which is mainly associated with the enhancement of sensible heat flux as we move from the eastern wet land to the western desert sector. It may be noted that the low level wind maximum, which is a characteristic feature over the monsoon region, is well simulated by this improved model physics.
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References
Anthes R A and Chang S W 1978 Response of the hurricane boundary layer to changes of sea surface temperature.J. Atmos. Sci. 35 1240–1255
Businger J A, Wyngaard J C, Izumi Y and Bradley E F, 1971 Flux-profile relationship in the atmospheric surface layer.J. Atmos. Sci. 28 181–189
Chang S W 1979 An efficient parameterization of convective and non-convective planetary boundary layers for use in numerical models;J. Appl. Meteorol. 18 1205–1215
Daly B J and Harlow F H 1970 Transport equations in turbulence;Phys. Fluids 13 2634–2649
Deardorff J W 1966 The counter gradient heat flux in the lower atmosphere and in the laboratory;J. Atmos. Sci. 23 503–506
Deardorff J W 1974b Three dimensional numerical study of turbulence in an entraining mixed layer;Boundary-Layer Meteorol. 7 199–226
Detering H W and Etling D 1985 Application of theE-ε turbulence model to the atmospheric boundary layer;Boundary-Layer Meteorol. 33 113–133
Gray W M 1975 Tropical cyclone genesis;Atmos. Sci. No. 234 (Colorado State University) 119p
Holt T and Sethuraman 1988 A review and Comparative Evaluation of Multi level Boundary Layer Parameterizations for First-order and Turbulent Kinetic Energy Closure Schemes;Rev. Geophys. 26 761–780
Krishnamurti T N, Cocke S, Pasch R and Low-Nam S 1983 Precipitation estimates from rain gauge and Satellite observations—Summer MONEX; FSU Report No. 83-7, May 1983, Florida State University, Tallahasse, Florida 373pp.
Krishnamurti T N, Oosterhot D and Nancy Dignon 1989 Hurricane prediction with a high resolution global model;Mon. Weather. Rev. 117 631–669
Kuo H L 1974 Further studies of the parameterization of the influence on cumulus convection on large scale flow;J. Atmos. Sci. 31 1232–1240
Madala R V, Chang S W, Mohanty U C, Madan S C, Paliwal R K, Sarin V B, Holt T and Sethuraman 1987 Description of Naval Research Laboratory Limited Area Dynamical Weather Prediction Model; N R L Tech. Report 5992, Washington D C 131pp
Mailhot J and Benoit R 1982 A finite element model of the atmospheric boundary layer suitable for use with numerical weather prediction;J. Atmos. Sci. 39 2249–2266
McBean G A K, Bernhardt S, Bodin Z, Litynska A P, Van Ulden and Wyngaard J C 1979, The Planetary Boundary Laver; WMO Tech Note 165 World. Met. Org.
Miller B I 1958 On the maximum intensity of hurricanes;J. Meteorol. 15 184–195
Mohanty U C, Paliwal R K, Madan S C, Tyagi A, Sarin V B and Ramesh K J 1987 Description of a limited area numerical weather prediction model for India and its neighbourhood; Centre for Atmospheric Sciences, IIT, Delhi.
Monin A S and Yaglom A M 1971 Statistical Fluid Mechanics; Vol I MIT Press 468–504
Namias J 1973 Birth of hurricane Agnes-triggered by the trans-equatorial movement of a mesoscale system into a favourable large scale environment;Mon. Weather Rev. 101 177–179
Palmen E 1948 On the formation and structure of tropical hurricanes;Geophysics 3 26–38
Perkey D J and Kreitzberg W 1976 A time dependent lateral boundary scheme for limited area primitive equation model;Mon. Weather Rev. 104 744–755
Seller W D 1965 Physical Climatology; (University of Chicago Press) 53–54
Shir C C 1973 A preliminary numerical study of atmospheric turbulent flows in the idealized planetary boundary layer;J. Atmos. Sci. 30 1327–1339
Tisdale C F and Clapp P F 1963 Origin and paths of hurricanes and tropical storms related to certain physical parameters at the air-sea surface;J. Appl. Meteorol. 2 358–367
Tyagi A, Mohanty U C and Ramesh K J 1994 Structure of the atmospheric boundary layer over the monsoon trough region;Mausam (In press)
Wyngaard J C 1975 Modeling the Planetary boundary layer—extension to the stable case;Boundary-Layer Meteorol. 9 441–460
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Potty, K.V.J., Mohanty, U.C., Nandi, B. et al. Planetary boundary layer over monsoon trough region in a high resolution primitive equation model. Proc. Indian Acad. Sci. (Earth Planet Sci.) 105, 81–100 (1996). https://doi.org/10.1007/BF02880760
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DOI: https://doi.org/10.1007/BF02880760