Tropical sea-breeze circulation and related atmospheric phenomena observedwith L-band boundary layer radar in Indonesia

High time-resolution data observed with L-band boundary layer radar in the equatorial region of Indonesia during dry season periods have been analyzed . The existence of tropical sea-breeze circulation, whose detectability has been reported in earlier works, is corroborated by performing intercompari sons with rawinsonde and surface meteorological measurements. In addition t o well defined circulation, anomalously weak echo patterns corresponding to the induced shear flow is also found to appear in several cases. Its origi n can be identified as Kelvin-Helmholtz type of instability which is believ ed to generate long lived turbulence activity that caused the gradient of p otential refractive index to be locally minimum. After sea-breeze intrusion , the planetary boundary layer is divided into layers with different charac teristics and cannot be considered as a homogeneous atmosphere throughout t he daytime. Although quantitative comparison has not been done, it is found that the observed sea-breeze scales do not seem to critically depend on Co riolis factor f as a primary scaling parameter.