EVALUATION OF TURBULENT FLUXES OVER MAITRI, ANTARCTICA

Turbulent fluxes have been evaluated for clear sunny days over the Ind ian Antarctic station, Maitri, using the basic meteorological data rec orded at four levels of a 28 m tower. The data are supplemented with r adiation data. The surface layer over Maitri remains thermally stratif ied during the hours of minimum solar insolation, the so-called nightt ime period. The surface winds during this period are generally very st rong resulting in high momentum fluxes. In particular, for high winds (>12 m s(-1)), the temperature gradient is found to be less positive t han for moderate winds (4 to 7 m s(-1)). Solar insolation provided the daytime heating necessary for the diurnal variation of atmospheric st ability, and hence, for the turbulent fluxes. Thus, on clear days dayt ime conditions are marked by upward transport of heat with reduced mom entum flux, while stable nighttime conditions are marked by a downward heat flux with increased momentum fluxes.