TITLE:
Rainfall Variation over Andhra Pradesh and Comparison with All Indian Rainfall during El Nino/La Nina
AUTHORS:
Dantuluri Jyothi, Basavani Pushpanjali, Mantravadi Venkata Subrahmanyam
KEYWORDS:
Andhra Pradesh Rainfall (APRF), All India Rainfall (AIRF), El Nino/La Nina, Seasonal Variation, Annual Variation
JOURNAL NAME:
Open Access Library Journal,
Vol.10 No.5,
May
17,
2023
ABSTRACT: Indian monsoon onset over Kerala (climatological mean is on 1st June with a deviation of ±10 days, but there are some exceptions), then monsoon progresses throughout India. Over Andhra Pradesh (AP), the summer monsoon or Southwest monsoon provides rainfall from June through September. An El Nino/La Nina event affects global phenomena such as the summer monsoon. Nino 3.4 index served as an index for forecasting El Nino/La Nina events. Nino 3.4 Sea Surface Temperature (SST) anomalies were used for this study to identify the El Nino/La Nina years, and they have been subdivided further as strong, moderate, and weak for a better understanding of the event in detail on rainfall. AP is having a special feature that, there are two types of climatic types for the study along with the variations over India. The Southwest monsoon rainfall Variations have been studied monthly (JJAS) and other seasons for the study period from 1950-2014 years and presented the results. The variations of AP rainfall (APRF) during different El Nino/La Nina years and compared with AIRF (AIRF). Previous studies concluded that there is a lag in AIRF after the El Nino event occurs, so we checked the feature for the AP. The monthly variations in the rainfall during El Nino/La Nina reveal that, there is a deficit in AIRF and APRF during El Nino years. During the La Nina years, excessive rainfall was found. Whereas during El Nino, there is an ambiguity in the rainfall being lower than normal rainfall while compared to the monthly and seasonal rainfall.