How Asian desert dust enhances Indian summer monsoon
Q. What is the news?
A recent study shows how dust coming from the deserts in the West, Central and East Asia plays an important role in the Indian Summer Monsoon.
The researchers also explain how the Indian Summer Monsoon has a reverse effect and can increase the winds in West Asia to produce yet more dust.
Q. What is Positive feedback loop?
Dust swarms from the desert when lifted by strong winds can absorb solar radiation and become hot. This can cause heating of the atmosphere, change the air pressure, wind circulation patterns, influence moisture transport and increase precipitation and rainfall. A strong monsoon can also transport air to West Asia and again pick up a lot of dust. The researchers say this is a positive feedback loop.
Q. How are aerosols transported?
Deserts across the globe play important roles 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. And in the southwest United States, some small deserts that influence the North African monsoon.
Experts are divided on the issue of whether , Anthropogenic dust from vehicles, mining, construction can influence monsoons, some see anthropogenic aerosols emitted from the Indian subcontinent can decrease summer monsoon precipitation, while others found that absorbing aerosols such as dust can strengthen the monsoon circulation.
Q. What are the minor components?
The research team has planned to study the minor components of desert dust aerosols. Dust from deserts across the globe will have the same components, but since different deserts have different chemical compositions and this can influence the dust’s properties. For example, if one think that dust from the Middle East [West Asia] has more absorbing ability of solar radiation than dust from North Africa and this difference in absorbing ability might influence monsoon systems.
Researchers have also planned to use high spatial resolution remote sensing to identify source regions and create a better dust emission map.
They would study new drying lakes and how dust from them can also play a role in the monsoons.
