Equatorial Warming, Black Carbon Induced Cooling and the Stability of the Indian Summer Monsoon
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
Equatorial Warming, Black Carbon Induced Cooling and the Stability of
the Indian Summer Monsoon
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| Creator |
K V, Ramesh
Goswami, P |
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| Subject |
Indian Monsoon
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| Description |
The response of regional circulation systems like the Indian Summer Monsoon (ISM) to the combined effects of
general global warming and local climate forcing, critical input for sustainability and mitigation policy, still remain
unclear. While warmer oceans1,2 and the higher tropospheric moisture associated with global warming3,4 point to
a more intense ISM, the long-period trends show it weakening5,6. We show here that a new dynamical regime is
emerging over the ISM region under the combined effects of general warming and local anthropogenic forcing.
There is a growing high temperature zone over the equator due to general global warming; however, the surface
temperature over India, increasing until around 1970 consistent with many model predictions7-9, began
decreasing subsequently under anthropogenic forcing associated with increasing black carbon emission10-12 over
India. The net effect is to intensify and accelerate the weakening, and even reverse, the land-equator thermal
gradient that plays a significant role in the evolution and the dynamics of the ISM13,14, such that the surface
westerlies that feed moisture to the continental monsoon trough now tend to veer southward. However, a quick
collapse of the ISM seems to be partially compensated by the continent ward turning of the winds from the Bay of
Bengal; the ISM as the main rain bearing system over India is thus currently in a state of delicate, evolving
balance. Conversely, there is a potential for a runaway collapse if the emission of black carbon grows such that a
feedback between reduced rain (a sink of black carbon) and cooling of the surface develops. Our results indicate
an urgent need for an energy policy to reduce black carbon emission to enable the stabilization and the recovery
of the monsoon.
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| Publisher |
CSIR Centre for Mathematical Modelling and Computer Simulation
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| Date |
2008-01
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| Type |
Monograph
NonPeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cir.cmmacs.ernet.in/266/1/rrcm0801.pdf
K V, Ramesh and Goswami, P (2008) Equatorial Warming, Black Carbon Induced Cooling and the Stability of the Indian Summer Monsoon. Technical Report. CSIR Centre for Mathematical Modelling and Computer Simulation , C-MMACS,Bangalore 560037,India. (Unpublished) |
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| Relation |
http://cir.cmmacs.ernet.in/266/
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