Satellite-observed latent heat release in a tropical cyclone

The latent heat release (LHR) and the distribution of rainfall rate of a tropical cyclone as it grows from a tropical disturbance to a typhoon were determined from Nimbus 5 Electrically Scanning Microwave Radiometer data. The LHR (calculated over a circular area of 4 deg latitude radius) increased during the development and intensification of the storm from a magnitude of 2.7 x 10 to the fourteenth W (in the disturbance stage) to 8.8 x 10 to the fourteenth W (typhoon stage). The latter value corresponds to a mean rainfall rate of 2.0 mm/h. The more intense the cyclone and the greater the LHR, the greater the percentage contribution of the larger rainfall rates to the LHR. As a cyclone intensifies, the higher rainfall rates tend to concentrate toward the center of the circulation.