Aerosols

Aerosols Latest News

A new study revealed that South Asia faces the highest climate impacts from dust-pollution aerosols, leading to significant atmospheric heating. 

About Aerosols

• Aerosols are tiny particles suspended in the atmosphere.
• Source: They originate from sources such as desert dust, vehicle emissions, industrial pollution and forest fires.
• Properties
  • Size: Aerosols range in size from a few tens of nanometers to several tens of micrometers.
  • These particles can either reflect sunlight back into space or absorb it,
  • They are often not or barely visible to the human eye, yet their impact on climate, weather, health, and ecology are significant.
  • These particles alter Earth’s energy balance and influence temperatures, cloud formation and rainfall.
• Types
  • Primary Aerosols: These are injected into the atmosphere directly and are known as ‘primary aerosols’. 
  • Examples: Sea spray, mineral dust, smoke, and volcanic ash are all primary aerosols.
  • Secondary aerosols: These are aerosols which were emitted in another form (e.g. gases), then become aerosol particles after going through chemical reactions in the atmosphere,
  • Example:  Sulfate aerosols from volcanoes or industrial emissions.

Key Highlights of the Study

• Scientists classified aerosols into seven categories:
  • Pure dust, dust-dominated mixtures, pollution-dominated mixtures, very weakly absorbing, weakly absorbing, moderately absorbing and strongly absorbing aerosols
• Pure dust dominates northern Africa, while Europe and North America are largely characterised by less-absorbing urban and industrial aerosols.
• Strongly absorbing aerosols, which often contain high levels of black carbon, produced the greatest atmospheric warming.
• Very weakly absorbing aerosols had the lowest atmospheric forcing, reflecting more sunlight back into space and producing a much smaller warming effect.
• Tropical regions affected by biomass burning are mainly dominated by strongly absorbing aerosols.
• Black carbon-rich aerosols drive stronger warming

Source: PIB

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