An analysis of MONTBLEX data on heat and momentum flux at Jodhpur

Abstract

Parameterization of sensible heat and momentum fluxes as inferred from an analysis of tower observations archived during MONTBLEX-90 at Jodhpur is proposed, both in terms of standard exchange coefficients C _H and C _D respectively and also according to free convection scaling. Both coefficients increase rapidly at low winds (the latter more strongly) and with increasing instability. All the sensible heat flux data at Jodhpur (wind speed at 10 m ̅U₁₀ < 8 ms⁻¹) also obey free convection scaling, with the flux proportional to the '4/3' power of an appropriate temperature difference such as that between 1 and 30 m. Furthermore, for ̅U₁₀ < 4 ms⁻¹ the momentum flux displays a linear dependence on wind speed.