Boundary Layer Development over a Tropical Island during the Maritime Continent Thunderstorm Experiment

Abstract Data collected during the Maritime Continent Thunderstorm Experiment (MCTEX) (10 November–10 December 1995) have been used to analyze boundary layer development and circulations over two almost flat, tropical islands. The two adjacent islands have a combined length of about 170 km from east to west and 70 km from north to south. Intense thunderstorms formed over these islands every day of the field campaign. The boundary layer depth, temperature, and circulation over the island have been measured over the full diurnal cycle using a multiple radar analysis combined with surface and radiosonde measurements. On average, the island boundary layer depth reaches 1.5 km by early to midafternoon coinciding with the development of the deep convection. Thus, the island boundary layer is significantly deeper than the typical tropical oceanic boundary layer. In the midafternoon, thunderstorm outflows and their associated cold pool stabilize the lower boundary layer, suppressing late convection. This is follo...