A numerical model study of the structure and similarity scaling of the nocturnal boundary layer (NBL)     

A. Lacser  S. P. S. Arya 《Boundary-Layer Meteorology》1986,35(4):369-385

A one-dimensional numerical model based on the equations of mean motion and turbulent kinetic energy (TKE), with Delage's (1974) mixing-length parameterization has been used to simulate the mean and turbulent structure of the evolving stably stratified nocturnal boundary layer (NBL). The model also includes a predictive equation for the surface temperature and longwave radiational cooling effects.In the absence of advective and gravity wave effects, it is found that the model-simulated structure, after a few hours of evolution, could be ordered fairly well by a similarity scaling (u _*0, _*0, L ₀, and h) based on surface fluxes and the NBL height. Simple expressions are suggested to describe the normalized profiles of momentum and heat fluxes, TKE, eddy-viscosity and energy dissipation. A good ordering of the same variables is also achieved by a local scaling (u _*0, _* and L) based on the height-dependent local fluxes. The normalized TKE, eddy viscosity and energy dissipation are unique functions of z/L and approach constant values as z/L , where L is the local Monin-Obukhov length. These constants are close to the values predicted for the surface layer as z/L , thus suggesting that the Monin-Obukhov similarity theory can be extended to the whole NBL, by using the local (height-dependent) scales in place of surface-layer scales. The observed NBL structure has been shown to follow local similarity (Nieuwstadt, 1984).  相似文献   

Plant remains from the Tharumsa Formation of Ladakh,India     

R. C. Mehrotra  Madhav Kumar  Amit K. Ghosh  K. Kumar  Ritesh Arya 《Journal of the Geological Society of India》2014,83(6):647-652

Plant remains, including both mega and micro collected from the middle part of the Tharumsa Foramtion (early Miocene) are described for the first time from the Tharumsa village of the Kargil district, Jammu and Kashmir to reconstruct the palaeoenvironment. They indicate their affinities with Broussonetia of the Moraceae and Abies, Cedrus and Pinus of the Pinaceae. Their presence indicates warm and moist tropical to sub-tropical climate in the Kargil area during the depositional period against the cold and dry climate prevailing at present.  相似文献