A few important features of global atmospheric boundary layer heights estimated using COSMIC radio occultation retrieved data

Abstract

This research reports the global atmospheric boundary layer height (ABLH, which is also known as the planetary boundary layer, PBLH) features estimated using COSMIC radio occultation (RO) retrieved temperature profiles during March, April, and May in 2015. Important analytical techniques including the vertical gradient and logarithmic gradient methods applied effectively on temperature profiles have revealed a few interesting features. Mainly, west coasts of the majority of the continents are associated with relatively lower magnitudes during the daytime hours, first of its kind observations reported using a space-based remote sensing technique. Secondly, over landmasses and desert areas, ABLHs show relatively higher magnitudes during the daytime hours, due to higher sensible heat flux. Thirdly, the cold land areas show relatively lower ABLHs, whereas cold oceans depict moderately higher values. In order to explain relatively low marine ABL (MABL) heights over the west coasts of the continents, we present a schematic diagram which includes various possible physical mechanisms that might be responsible for these extremely low MABL heights. This research emphasizes that the COSMIC RO is a powerful global technique, which is able to unravel the link between ocean and the Earth’s lower atmospheric dynamics.