PM, Shah discuss damage control, Raje cancels Punjab visit

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.

New Delhi, Jul 2: In the midst of India's tense border standoff with China, the defence ministry on Thursday approved procurement of a number of frontline fighter jets, missile systems and other platforms at a cost of Rs 38,900 crore to bolster the combat capability of the armed forces, officials said.

They said 21 MiG-29 fighter jets are being bought from Russia while 12 Su-30 MKI aircraft will be procured from Russia. The ministry has also approved a separate proposal to upgrade existing 59 MiG-29 aircraft.

The decisions were taken at a meeting of the Defence Acquisition Council (DAC) chaired by Defence Minister Rajnath Singh.

The procurement of 21 MiG-29 and upgrading of the existing fleet of MiG-29 are estimated to cost the government Rs 7,418 crore while purchase of 12 new Su-30 MKI from the Hindustan Aeronautics Ltd will be made at a cost of Rs 10,730 crore, the officials said.

The DAC also approved procurement of long-range land-attack cruise missile systems with a range of 1,000 KM and Astra Missiles for Navy and Air Force.

The officials said cost of these design and development proposals is in the range of Rs 20,400 crore.

"While acquisition of Pinaka missile systems will enable raising additional regiments over and above the ones already inducted, addition of long-range land attack missile systems having a firing range of 1000 KM to the existing arsenal will bolster the attack capabilities of the Navy and the Air Force," said a defence ministry official.

"Similarly induction of Astra Missiles having beyond visual range capability will serve as a force multiplier and immensely add to the strike capability of the Indian Navy and the Indian Air Force," he said.