Global mapping of height of bright band

Radar observations of the melting layer of precipitation have been made since the dawn of radar meteorology [1,2]. It has been known since then that the melting of precipitation is often associated with an enhancement of the reflectivity of weather targets. The primary cause of the enhancement is a rapid increase in the dielectric constant of hydrometeors at the top of the melting layer followed by an increase of the velocities of melting snowflakes toward the end of the melting process [3]. The radar bright band results mostly from melting of snowflakes as they fall through the 0°C isotherm. As the ice is gradually transformed to liquid, the refractive index and, hence, the back-scattering cross section increase, and the radar echo intensity increases to a maximum at ≈ 200m below the 0°C isotherm. The decrease of echo intensity below the bright band level is mostly the result of decreases of particle concentration caused by increases of terminal velocity as the particles melt. 2A23 TRMM data provides information about the height of bright band (HBB) as well as the height of freezing. HBB is generally close to the height of freezing (usually within ± 2 km). In this paper, data from the TRMM PR are used to generate monthly maps of the height of bright band (HBB over the globe for the year 2000, 3dB thickness of BB is developed, HBB over ocean and land and during some events such as hurricane are examined.