Arabian Sea cyclone: Structure analysis using satellite data

Abstract

Advances in earth observation technology over the last two decades have resulted in improved forecasting of various hydrometeorological-related disasters. In this study the severe tropical cyclone Gonu (2–7 June, 2007) was investigated using multi-sensor satellite data sets (i.e. AIRS, METEOSAT, MODIS and QSCAT data) to monitor its overall structure, position, intensity, and motion. A high sea surface temperature and warm core anomalies (at 200hPa and above) with respect to the pressure minima in the central core were found to have influenced the pattern of development of the tropical cyclone. High relative humidity in the middle troposphere was aligned with temperature minima at 850hPa and 700hPa; high winds (above 120 knots) and closed pressure contours were observed during the intensification stage. A contour analysis of outgoing longwave radiation (OLR) provided an explanation for the direction of movement of the cyclone. The translational movement and velocities (ground speed) of the tropical cyclone were calculated using the surface pressure of the cyclone’s central core. Statistical analyses revealed a strong correlation between the maximum wind speeds within the cyclone and various atmospheric parameters. We conclude with a discussion of the significance of these findings with regard to cyclone forecasting within the framework of early warning and disaster management.