Indian Journal of Science and Technology

Abstract

Objectives: Although several methods are available to identify ABLHeight (ABLH), a comprehensive study on the usage of different analytical methods has not been reported widely, particularly on global databases. Methods/Analysis: In this research, we use various analytical methods including, gradient, double gradient and logarithmic gradient to estimate ABLH during two months (March and April 2013) period and applied those methods on COSMIC Radio Occultation retrieved temperature profiles to estimate ABLH. Findings: The estimated ABLHs are arranged in order to present them globally and diurnally that clearly show a few distinct features. Mainly, land and desert areas are associated with higher ABLH during daytime hours. Cold land areas (Arctic and Greenland) show relatively lower magnitudes and reverse are the cases with ABLH over cold oceans (Antarctic oceans). Most importantly, a distinctive diurnal feature is observed with a peak at sharp noon time and relatively lower values in the night time, which indicate both convective and stable layers, have evolved based on the ambient conditions that would exist during the day and nighttime ambient conditions. However, morning and evening transitions are not found in diurnal variations. Applications/Improvements: It is found that both gradient and logarithmic methods are able to find accurate ABLH, though still a great room exists to verify various other methods in finding ABLH. 

Keywords: Atmospheric Boundary Layer Height, Analytical Methods, COSMIC RO Technique, Stable and Convective Layers