Indian Summer Monsoon impacts on Bay of Bengal Cyclones through River Water Discharge (#1056)
Our study is on the impact of Indian Summer Monsoon on the frequency of Tropical Cyclones in the Bay of Bengal (BoB) during the post-monsoon (October- November) period. BoB receives a large amount of freshwater through river runoff from the major Monsoon-fed rivers. Our study shows that the frequency of cyclonic activity during post-monsoon period is higher (lower) following a heavy monsoon (drought) period. The impact is stronger during October and November months with no effect during December. The large influx of freshwater strengthens the Barrier Layer and forms shallower Mixed Layer Depth (MLD) over the Bay of Bengal. Shallower MLD indicates lesser volume of seawater to be heated from the same amount of solar insolation. This indicates a greater heat retention in MLD thereby increasing the availability of Heat energy and subsequently an increase in the frequency of cyclones. Calculation of the Tropical Cyclone Heat Index confirms our findings of increased (decreased) in cyclonic activity post heavy rainfall (drought).