Man arrested for questioning Mamata, activists condemn incident

Washington, Apr 23: Air pollution over northern India has plummeted to a 20-year-low for this time of the year, according to satellite data published by US space agency National Aeronautics and Space Administration (NASA).
The US space agency's satellite sensors observed aerosol levels at a 20-year low post the countrywide lockdown, implemented to slow the spread of the novel coronavirus.

"We knew we would see changes in atmospheric composition in many places during the lockdown," said Pawan Gupta, a Universities Space Research Association (USRA) scientist at NASA''s Marshall Space Flight Center. "But I have never seen aerosol values so low in the Indo-Gangetic Plain at this time of year," added Mr Gupta.

Acting Assistant Secretary of State for South and Central Asia Alice G Wells tweeted, "These images from NASA were taken each spring starting in 2016 and show a 20-year low in airborne particle levels over India. When India and the world are ready to work and travel again, let's not forget that collaborative action can result in cleaner air."

The data published with maps show aerosol optical depth (AOD) in 2020 compared to the average for 2016-2019. Aerosol optical depth is a measure of how light is absorbed or reflected by airborne particles as it travels through the atmosphere.

If aerosols are concentrated near the surface, an optical depth of 1 or above indicates very hazy conditions. An optical depth, or thickness, of less than 0.1 over the entire atmospheric vertical column is considered "clean." The data were retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite.

In the first few days of the lockdown, it was difficult to observe a change in the pollution signature. "We saw an aerosol decrease in the first week of the shutdown, but that was due to a combination of rain and the lockdown," said Mr Gupta.

Around March 27, heavy rain poured over vast areas of northern India and helped clear the air of aerosols. Aerosol concentrations usually increase again after such heavy precipitation.

"After the rainfall, I was really impressed that aerosol levels did not go up and return to normal. We saw a gradual decrease and things have been staying at the level we might expect without anthropogenic emissions," Mr Gupta said.

On March 25, the Indian government placed its 1.3 billion citizens under a strict lockdown to reduce the spread of COVID-19. The countrywide mandate decreased activity at factories and severely reduced car, bus, truck and airplane traffic. Every year, aerosols from anthropogenic (human-made) sources contribute to unhealthy levels of air pollution in many Indian cities.

Aerosols are tiny solid and liquid particles suspended in the air that reduce visibility and can damage the human lungs and heart.

In southern India though, the story is a little hazier. Satellite data show aerosol levels have not yet decreased to the same extent. In fact, levels seem to be slightly higher than in the past four years. The reasons are unclear but could be related to recent weather patterns, agricultural fires, winds or other factors.

"This a model scientific experiment," Robert Levy, program leader for NASA's MODIS aerosol products, said about the lockdown and its effects on pollution.

"We have a unique opportunity to learn how the atmosphere reacts to sharp and sudden reductions in emissions from certain sectors. This can help us separate how natural and human sources of aerosols affect the atmosphere," Mr Levy added.

Mumbai, Jan 28: Flag carrier Air India has kept one of its 423-seater jumbo planes ready in Mumbai for the evacuation of Indian citizens from Wuhan in China in the wake of the coronavirus outbreak in that country, an official source said on Tuesday.

The airline is awaiting necessary approvals from the ministries of external affairs and health to operate the special flight, the source said. The health ministry's nod is required because the operating crew has to fly in a virus outbreak territory.

"We have kept a Boeing 747-400 ready in Mumbai to operate an evacuation flight to China whenever we get a go ahead from the government," the source said.

Some 250 Indians are to be evacuated.

At a meeting of top secretaries called by the cabinet secretary on Monday, the government decided to be prepared for possible evacuation of Indian nationals in Wuhan.

Accordingly, Ministry of External Affairs will make a request to the Chinese authorities for evacuation of Indian nationals, mostly students, stuck in Wuhan city. The Ministry of Civil Aviation and Ministry of Health will make arrangements for transport and quarantine facilities respectively, an official release said on Monday.

Wuhan along 12 other cities have been completely sealed by the Chinese authorities to stop the virus from spreading. The death toll climbed to 80 with 2,744 confirmed cases.

New Delhi, Feb 1: India on Friday banned the export of personal protection equipment such as masks and clothing amid a global coronavirus outbreak.

It did not give a reason for the ban but it reported its first case of the new coronavirus on Thursday, a woman in Kerala who was a student of Wuhan University in China.

The central Chinese city of Wuhan is the epicentre of the outbreak, and the virus has since spread to more than 9,800 people globally and killed 213 people in China.

Several Indian citizens living in Wuhan will arrive in India by plane on Saturday and be taken to a quarantine centre on the outskirts of the capital New Delhi.

India, the world’s second most heavily populated country after China, has taken measures to ensure that all people arriving from China report to health authorities.