This region is well known for vigorous atmospheric convection that drives the global atmosphere (e.g., Neale and Slingo 2003) through the updraft branch of the Walker circulation (e.g., Lau and Yang 2002) and for being the source of the off-equatorward propagating signal known as the “Pacific-Japan pattern” (Nitta 1987). The Maritime Continent (MC Ramage 1968) is characterized by a mosaic of ocean regions with high sea surface temperatures and islands with various sizes, forms, and terrains.

The possible physical processes promoting lower-tropospheric moistening before onset of the convective rain are also discussed. The diurnal composite of the obtained parameters revealed key processes such as (1) just before the onset of the afternoon convective rain, the lower troposphere was moistened by subarray-scale processes (2) moistening of the troposphere continued during the convective heavy precipitation (3) the stratiform rains during the night were partly maintained by consuming the pre-existing hydrometeor aloft and (4) in the early morning, the clouds redeveloped over the ocean to produce precipitation as well as hydrometeor aloft.

The period-averaged vertical profiles of Q1 and Q2 indicate that diurnal precipitation acted as deep convection in the diabatic heating and drying. Thermodynamic budget analyses were also performed using sounding data. Radar and satellites captured the convective-type heavy rains that appeared in the afternoon over the array, which were followed by stratiform-type precipitation during the night. During the 1-month campaign, diurnal cycles over Jakarta were well identified by special networked soundings and a C-band radar. This study investigates the nature and mechanisms of the diurnal precipitation system over a coastal area of the Maritime Continent (MC) by utilizing the data from a field campaign, HARIMAU2010.

Dbz s cells