Dust and sea salt aerosols over the Indian Ocean region during different phases of ENSO and their association with the Indian Summer Monsoon variability
Student name: Ms Monika Chakraborty
Guide: Dr Kamna Sachdeva
Year of completion: 2018
Host Organisation: IIT Delhi
Supervisor (Host Organisation): Dr Dilip Ganguly
Abstract: Through this study, we present observational evidence, based on MERRA
reanalysis data and satellite aerosol measurements for the period 1981–2017,
indicating that absorbing aerosols (Black Carbon, SO4, Organic Carbon, Sea Salt
and Dust) can have a very strong influence on seasonal-to-inter annual variability
of the Indian summer monsoon rainfall, including the amplification of El Nino, La
Nina and ENSO effects. We are trying to establish a correlation between El Nino,
La Nina and aerosol loading in April–May, June-July-August-September with La
Nina (El Nino) conditions favoring in increase (decreased) of dust and sea salt
accumulation over Indian coastal region especially in the Arabian Sea also with
maximum aerosol optical depth over the Arabian Sea. It also indicates the strong
concentration of dust aerosols transported from Middle East and West Asia deserts.
Studies have already proved and reported that El Niño–Southern Oscillation (ENSO)
not only influence the summer monsoon, but also the winter monsoon over the entire
East Asia. In the year 2010, under the emission level of aerosols, atmospheric
anthropogenic aerosol content in winter over southern China was greater (less) than
normal in El Niño (La Niña) winter. The transport of the aerosols from the South
East Asia and South Asia to the southern part of China was the prime reason of this
abnormal activity which further provided the required scavenging conditions for
aerosols in the winter El Nino (La Nina). This laid the foundation of our study to
check the effect of such El Nino (La Nina) over the Indian subcontinent and the
effect of aerosols over these phenomenons.
