Asian Brown Cloud A Climate change phenomenon

Asian Brown Cloud/ Indian Ocean Brown Cloud

Layer Areas covered Term coined Period of occurrence Thickness & Size

25/03/2015 Asian Brown Cloud 2

What is it?

History

INDOEX observed-1999

UNEP published-2002

Follow up InternationalProject

NASA-2004 & 2007

Atmospheric Brown Cloud

Widespread layers of brownish haze

Regions Indo Gangetic Plain in South Asia

East Asia

Indonesian Region

Southern Africa extending southwards

The Amazon basin in South America

25/03/2015 Asian Brown Cloud 3

Causes

Large amounts of aerosols

Smoke

Precursor gases

Black Carbon

Soot

25/03/2015 Asian Brown Cloud 4

Fossil Fuels EmissionsBiomass Combustion

Source

Content

Effects Reduce the amount of sunlight - 10 to 15%

Enhance atmospheric solar heating - 50%.

Mask the greenhouse warming

Enhance the greenhouse warming

Confirmed masking - 50%

25/03/2015 Asian Brown Cloud 5

Regional Climate

Slowing down & Reductionof the monsoon

Increase strength andfrequency of winter

Spring time temperatureinversion.

Enhancing the greenhousewarming

Impacts on precipitationpatterns and water budgets

25/03/2015 Asian Brown Cloud 6

25/03/2015 Asian Brown Cloud 7

Aerosols nucleate cloud dropsSize decreasesLifetime extended

Influence on Cloud Properties

Decrease wheat/rice yield upto 7-8 % as predicted by simulative models

Agriculture

cardiovascularpulmonary effectschronic respiratory problems

Health effects

Facts

Southward shift of the summer monsoon in eastern China

A study published in the British journal Nature claims the thickplume that languishes over the region is as much to blame asgreenhouse gases for the warming of 46,000 glaciers on theTibetan Plateau, the third-largest ice mass on the planet.

The effects have been linked to the retreat over the past halfcentury of glaciers in the Himalyas which supply water to majorrivers including the Yangtze, Ganges and Indus. These rivers in turncomprise the chief water supply for billions of people in China,India and other south Asian countries.

25/03/2015 Asian Brown Cloud 8

Long-term worry is of drought as the glaciers continue to shrink,according to researchers led by Veerabhadran Ramanthan, professorof atmospheric sciences at the Scripps Institution of Oceanographyin California. Slowing down of the monsoon circulation andreduction in monsoon rainfall.

The effect of ABCs on climate, hydrological cycle, glacier melting,agriculture and human health is an outstanding problem whichprevents a complete understanding of climate change and itsimpacts, and needs to be more fully explored.

The consequences for China, India and other countries whose riversflow from this source are incalculable, with the melting alreadybeing blamed for downstream flooding in late summer.

25/03/2015 Asian Brown Cloud 9

Facts

References

www.telegraph.co.uk

www.rrcap.unep.org- Regional Resource Center for Asia and thePacific (RRC.AP) at Asian Institute of Technology - A UNEPCollaborating Centre

Ramanathan, V., Chung, C., Kim, D., Bettge, T., Buja, L., Kiehl, J.T.,Washington, W.M., Fu, Q., Sikka, D.R. and Wild, M. (2005).Atmospheric brown clouds: Impacts on South Asian climate andhydrological cycle. In Proc. Natl. Acad. Sci. 102:5326-5333

www.britannica.com

25/03/2015 Asian Brown Cloud 10

Thank you- Srujani Shrawne (TE Environment)

25/03/2015 Asian Brown Cloud 11