On stability correction functions over the Indian region under stable conditions

Turbulence observations over an Indian region are used to examine the observational behaviour of stability-correction functions for momentum (φm) and heat (φh) under stable conditions within the framework of Monin–Obukhov similarity theory. The φm is observed to follow the linear functional form in the case of near-neutral to moderately stable conditions. However, φm is found to increase with a relatively slower rate as compared with the linear form in strongly stable conditions. A large scatter in φh is observed with the near neutral condition, and they tend to level off in very stable conditions. The optimized co-efficients appearing in the functional form of φm suggested by Grachev et al. in 2007 are derived using turbulence observations. The present study recommends the use of these optimized functional forms of φm and φh for the estimation of surface fluxes over an Indian region in atmospheric models.