Rasch-Slide-Indian Summer Monsoon-Feb2014

1
Mighty Indian Monsoon Responds to the Deserts
Breath

• Objective
• Explore the link between aerosols and the Indian
  summer monsoon rainfall
• Explain such a link using both observations and
  climate model simulations
• Approach
• Use satellite measurements to find a correlation
  between Indian monsoon rainfall and aerosol
  variations over the Arabian Sea, North Africa and
  West Asia
• Confirm that a similar relationship occurs in a
  global climate model (CAM5)
• Propose a mechanism to connect variations in
  naturally occurring dust aerosols to the west of
  India with Indian monsoon rainfall on short (1
  week) timescales
• Perform simulation experiments that demonstrate
  why and how the mechanism operates

The hypothesis explains the interaction between
remote dust aerosols residing to the west of
India affecting monsoon rainfall on short time
scales

• Impact
• A simple analysis indicates a distinct,
  observable relationship between dust aerosol and
  Indian summer monsoon rainfall with variations
  that are strongly correlated on timescales of
  about a week
• Although there has been a lot of recent attention
  on the role of anthropogenic aerosols on the
  monsoon, this study indicates that natural
  aerosol variations also play a role.

Vinoj V, PJ Rasch, H Wang, J-H Yoon, P-L Ma, K
Landu and B Singh. 2014. Short-term Modulation
of Indian Summer Monsoon Rainfall by West Asian
Dust. Nature Geoscience 7. DOI
10.1038/NGEO2107.