Near-surface temperature inversion over the Arabian Sea due to natural aerosols

Abstract

A daytime, near-surface temperature inversion is observed over the open Arabian Sea during the summer monsoon season. During such periods, the temperature profile in the surface layer can no longer be described using the Monin-Obukhov similarity profile. The diurnal change in air temperature is 10 times that of the water below, and the direction of heat flow between ocean and atmosphere reverses during a day in a manner opposite to that found over land. This coincides with strong surface winds and high levels of sea salt particle concentration in the boundary layer. Radiative transfer calculations show that at the observed levels of aerosol optical depth, the absorption in the solar spectrum exceeds the emission in the infrared around noon hours. This can result in the near-surface inversion. Copyright 2006 by the American Geophysical Union.