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NASA satellite sensors observed “aerosol levels in a minimum of 20 years for this time of year in North India” after just a week of reduced human activities, such as the closure of many factories and vehicle traffic and planes, a situation that allowed some in Punjab to report seeing some Himalayan mountain ranges with the naked eye for the first time in many years.
The space agency, however, noted that the history in South India is a bit more dangerous as satellite data shows that aerosol levels have not yet decreased to the same extent and the levels, in fact, appear to be slightly higher than in the last four years. Although the reasons are unclear, he said, it could be related to recent weather patterns, wind, or other factors.
“According to all reports, the close of 2020 reduced those man-made emission sources,” said a report from NASA’s Earth Observatory that analyzed the data, retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) at NASA’s Terra satellite.
“We knew that we would see changes in atmospheric composition in many places during closure. But I have never seen such low aerosol values on the Indo-Gangetic Plain at this time of year, “said Pawan Gupta, a scientist at the University Space Research Association (USRA) at NASA’s Marshall Space Flight Center.
Although some aerosols have natural sources (dust storms, volcanic eruptions, and forest fires), the others come from human activities, such as burning fossil fuels and agricultural fields.
The NASA Earth Observatory report on its website by its scientific writing Kasha Patel noted that man-made aerosols “tend to contribute most of the smallest particles that have the greatest potential to harm human health” . The report says such sprays contribute to unhealthy levels of air pollution in many Indian cities.
However, scientists expect aerosol levels to rise slightly in the coming weeks in some parts of India as seasonal dust storms begin from the Thar Desert and the Arabian Peninsula.
“The difficult part of understanding aerosols is that the particles can move based on wind patterns and other weather. You have to untangle what is caused by the human fingerprint versus a weather factor, “said Robert Levy, leader of NASA’s MODIS aerosol product program.
On the blockade and its effects on pollution, Levy said: “We have a unique opportunity to learn how the atmosphere reacts to sudden and sudden reductions in emissions from certain sectors. This can help us separate how natural and human sources of aerosols affect the atmosphere. ”
Previously, the Central Pollution Control Board (CPCB), the national pollution control agency of India, also in its report on the “impact of the curfew and the blocking of Janta on air quality” on March 31, he observed a substantial improvement in air quality in many towns and cities across the country. He attributed this improvement to strict travel restrictions and the closure of non-essential activities, including those in the air-polluting sectors. The Board analyzed real-time air quality data from 115 cities from March 16 to 29 to assess the impact of the blockade.
