Impacts of Desert Dust Particles on “Indian Summer Monsoon”

What is the News? A new study shows the impacts of desert dust coming from the West, Central, and East Asia in the Indian Summer Monsoon.

Impacts of Desert Dust Particles on Indian Summer Monsoon:

• Strong winds carry the dust particles from the Middle East into the atmosphere. Dust particles absorb solar radiation and become extremely hot.
• This causes the atmosphere to heat. The heat decreases the air pressure and changes wind circulation patterns. Further, it increases the moisture transport capacity of air and increases precipitation and rainfall.
• This phenomenon is termed an “elevated heat pump”. It is responsible for driving moisture from the sea to the Indian subcontinent.

Positive Feedback Loop:

• Positive Feedback Loop is a loop where the result of a reaction leads to an enhancement of that very reaction.
• In this case, too, a positive feedback loop plays a role when the dust particles from the Middle East boost the power of Indian monsoons.
• In turn, the monsoons increase the winds in the Middle East and subsequently produce more dust aerosols.

Role of Iranian Plateau on Indian Summer Monsoon:

• Iranian Plateau also influences the Indian Summer Monsoon. The hot air over the Iranian Plateau can heat the atmosphere over the plateau. It further strengthens the circulation over the deserts of the Arabian Peninsula and increases dust emission from the Middle East [West Asia].

Influence of Aerosols on Indian Summer Monsoon:

• 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, mist, dust, forest exudates, and geyser steam.
  • Examples of anthropogenic aerosols are particulate air pollutants and smoke.
• Some studies have found that anthropogenic aerosols emitted from the Indian subcontinent can decrease summer monsoon precipitation.
• While other studies have found that absorbing aerosols such as dust can strengthen the monsoon circulation.
• However, in this study, it was found that anthropogenic aerosols can strengthen Indian summer monsoon rainfall.

Influence of Dust Particles across the Globe: Dust Particles from deserts across the globe play important role in monsoons:

• The dust aerosols from deserts in West China such as the Taklamakan Desert and the Gobi Desert can be transported eastward to eastern China and can influence the East Asia summer monsoon.
• The small deserts in the southwest United States are known to influence the North African monsoon.

Source: The Hindu