Climatology of the subtropical high-pressure belt

Abstract

In this paper, the authors aim to study a few meteorological elements, viz. rainfall, the freezing level height (HFL), bright band height (BBH), and the bright band intensity (BBI) at the subtropics, with special emphasis on the STHP. The study reveals a stunning finding. Unlike the low latitudes, the bright band height (BBH) lies above the freezing level height (HFL) at the subtropics. Besides, the study shows that as the latitude increases, the probability of BBH>HFL increases. The probability of BBH>HFL is the maximum at the STHP, in comparison to the lower latitudes. The investigation shows that the STHP is not the region of the least rainy belt in the 35N-35S region always. However, in most of the months, and most of the years, it shows very low rain. The study shows the daily, monthly, and yearly variations of rainfall, HFL, BBH, and BBI, and their correlations. The authors aim in particular, to find out if the maximum (minimum) rainfall in this region corresponds to the maximum (minimum) BBI and BBH. The HFL, BBH, and BBI for the period 1999-2002, and 2007-2008 have been obtained from the data product 2A23 of the precipitation radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite. The rainfall for the period 2004-2008 has been obtained from the data product 2A12 of the Tropical Microwave Imager (TMI) onboard the TRMM. Besides, the authors investigated the surface temperature, surface pressure, relative humidity, and precipitable water over a few locations in the subtropics. The study shows the interrelations of rainfall with surface elements. These surface elements have been obtained from the Integrated Global Radiosonde Archive (IGRA). The study also investigates the impact of the El Nino/La Nina on HFL.