Why in News?

• Small aerosol particles help in “brightening” of clouds, enabling them to alter Earth’s radiative balance and ultimately its climate, according to a study.

Aerosol:

• An aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas.
• Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam.
• Examples of anthropogenic aerosols are haze, particulate air pollutants and smoke.
• Formation in atmosphere:
• When deep, convective clouds in the tropics carry gases high into the atmosphere, they form small aerosol particles in a process called gas-to-particle conversion.
• As they condense, they grow big enough to brighten lower-level cloud in the lower troposphere.
• This gas-to-particle conversion brightens clouds in the tropics over both the Pacific and Atlantic Oceans.

Significance:

• These brighter clouds reflect more energy from the sun back to space.
• Further, this formation of new particle covers about 40 per cent of the Earth’s surface, which means some of the current climate models underestimate the cooling impact of some clouds.
• Understanding how these particles form and contribute to cloud properties in the tropics will help us better represent clouds in climate models and improve those models.
• The study showed that in remote places with cleaner air, the effect of aerosol particle formation on clouds was found to be much larger.