Study of Moisture Budget of Meteorological Droughts over Indian Region

• Published in: Modern applied science 2018-08, Vol.12 (9), p.221
• Main Authors: Suneetha, P., M. D., Zedek, S., Ramalingeswara Rao, K., Naga Lakshmi, P., Latha, Kumar, O. S. R. U. Bhanu, Govt, V. S. Krishna
• Format: Article
• Language: English
• ISSN: 1913-1844; 1913-1852
• DOI: 10.5539/mas.v12n9p221

The study mainly focuses on heat and moisture budget components and its variations during meteorological drought conditions over India for the period 1951-2013. IITM sub-divisional summer monsoon standardized rainfall anomaly is considered to identify the meteorological drought where the standardized summer monsoon rainfall anomaly is less than one. From the analysis, there are thirteen meteorological droughts are identified, and the rainfall decreased on spatial and temporal scales with significant changes in the frequency, duration and total amount of rainfall. Mainly, anticyclonic circulation is observed along 60⁰-70⁰E with weak westerlies at lower levels. At the upper level, the intensity of easterly jet stream is decreased and shifted southward during drought years.Anomalous variations in relative humidity and vertical velocity induce the maximum reduction in the moisture amount (15%) at lower and upper levels leads to weakening of the strength of local Hadley circulation. Next, the heat budget components are decreased over Bay of Bengal and coastal regions with a magnitude of 40 to 200 W/m2 in drought years. It is observed that more moisture is transported to the equatorial region producing below average rainfall over the Indian subcontinent during weak monsoon periods. Hence, this study will help to identify the quantitative and qualitative estimation of drought conditions for long-range prediction of rainfall forecasting.