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New study says haze may be contributing to warming in South Asia

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[vc_row][vc_column][vc_column_text]By Dinesh C Sharma

The haze over the national capital and Northwest India seen during winters is not only causing problems to people on the ground but also impacting atmospheric climate. A new study by an international group of researchers has found that the composition of a class of carbon-carrying aerosols in the haze changes as it travels from above the landmass to the oceans.

The light absorption capacity of brown carbon – a key component of the haze – decreases during transport but its bleaching half-life is 3.6 days compared to 9 to 15 hours in other regions. This means that brown carbon stays in the South Asian atmosphere for a longer duration and thereby may contribute to warming of the region, according researchers.

The haze, also called atmospheric brown cloud (ABC), contains several types of particles emanating from vehicular pollution, biomass burning and other sources. This layer of polluted air plays critical role in regional climate as it both absorbs and scatters incoming solar radiation.

Sanjeev Dasari, lead author of the study

Sanjeev Dasari, lead author of the study

Two important light-absorbing components of ABC are black carbon and brown carbon. While black carbon mainly comes from sources like diesel combustion, brown carbon is a result of biomass burning. The new study focused on brown carbon as little was known about its light absorption capacity as it travels over the oceans.

Researchers measured air samples in Delhi, located in the midst of India-Gangetic Plains; Bhola in South Bangladesh which is at the edge of IGP; and at the Maldives Climate Observatory at Hanimaadhoo where the brown cloud reaches after long-range over-ocean transport.

It was found that the chemical composition of the aerosols changed between sites and over time. Water-soluble brown carbon concentrations were highest in Delhi, lower at the site in Bangladesh and lowest in the Maldives. Measurements of water-soluble extracts of brown carbon showed notable differences in light absorption characteristics between the three locations, with brown carbon molecules losing their warming capacity during transport, according to the study published in journal Science Advances on Thursday.

“Through measurements at three locations, we were able to determine the ability of brown carbon to absorb solar light (and thus warm the surrounding atmosphere) and how fast this ability was decreasing due to a photochemical oxidation – a process we call bleaching,” explained Prof Örjan Gustafsson (Department of Environmental Science and Analytical Chemistry, Stockholm University), senior member of the research team, in an e-mail interview with India Science Wire.

Since brown carbon in South Asia seems to have longer bleaching half-life, it has implications on warming in the region. “As of now, we cannot comment what is the ‘true’ warming capacity of brown carbon. We can, however, say that previous global modelling studies relying on ‘set’ values of brown carbon light-absorption might have wrongly estimated the warming effect,” explained Sanjeev Dasari, PhD student at Stockholm University and first author of the study, while speaking to India Science Wire.

“This study is for winter months but still has crucial information considering that the leading hypothesis for the reduction in monsoon over the past few decades has been the solar dimming by aerosols. It is clear that both climate prediction and projection models need to understand impacts of such drastic transformation of brown carbon properties,” commented Raghu Murtugudde, professor of Atmospheric and Oceanic Science and Earth System Science at the University of Maryland and a visiting professor at IIT Bombay. He was not associated with the study.

The research team included Sanjeev Dasari, August Andersson, Srinivas Bikkina, Henry Holmstrand, Krishnakant Budhavan, Örjan Gustafsson (Stockholm University); Sreedharan Sathees (Indian Institute of Science, Bangalore); Eija Asmi, Jutta Kesti, John Backman (Finnish Meteorological Institute); Abdus Salam (University of Dhaka); Deewan Singh Bisht, Suresh Tiwari (Delhi centre of Indian Institute of Tropical Meteorology); and Zahid Hameed (Maldives Meteorological Service). (India Science Wire)[/vc_column_text][/vc_column][/vc_row]

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Indian-origin astronaut Anil Menon begins first mission to International Space Station

Indian-origin NASA astronaut Anil Menon has launched aboard Soyuz MS-29 on his first mission to the International Space Station, where he is expected to spend around eight months conducting research.

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Indian-origin NASA astronaut Anil Menon has embarked on his first journey into space after successfully launching aboard Russia’s Soyuz MS-29 spacecraft to the International Space Station (ISS).

The mission lifted off from the historic Baikonur Cosmodrome in Kazakhstan at 8:17 PM on Tuesday. Menon was accompanied by Russian cosmonauts Pyotr Dubrov and Anna Kikina as the three-member crew began their expedition to the orbiting laboratory.

Crew to spend about eight months aboard ISS

The Soyuz MS-29 spacecraft is expected to dock with the International Space Station a little over three hours after launch. Once aboard the ISS, the crew will carry out a range of scientific research and technology demonstration projects during their mission.

The expedition is scheduled to last approximately eight months, with the crew expected to return to Earth in 2027 after completing their planned activities in orbit.

Menon’s maiden spaceflight marks a significant milestone in his astronaut career as he joins the International Space Station crew for long-duration research and operational work.

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Astronaut Shubhanshu Shukla to meet PM Modi after return from historic space mission

Astronaut Shubhanshu Shukla, who recently returned from the ISS as part of the Axiom-4 mission, will meet PM Modi this evening. Parliament will also hold a special discussion on his historic journey.

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Subhanshu shukla

Indian astronaut Group Captain Shubhanshu Shukla, the first Indian to visit the International Space Station (ISS), will meet Prime Minister Narendra Modi this evening at his official residence in New Delhi.

PM Modi to host meeting with astronaut

According to officials, the meeting at 7 Lok Kalyan Marg is expected to take place between 5 pm and 5:30 pm. Shukla, who arrived in India on Sunday, will also be part of the National Space Day celebrations scheduled for August 23.

Warm welcome in India

The astronaut was greeted at the airport by his family, Science and Technology Minister Jitendra Singh, Delhi Chief Minister Rekha Gupta, and hundreds of citizens waving the national flag. Shukla had been in the United States for a year, preparing for the Axiom-4 mission, which launched from Florida on June 25 and docked at the ISS the next day. He served as the mission’s pilot.

Emotional note from Shukla

Before his return, Shukla shared an emotional post on Instagram, expressing mixed feelings of leaving his space colleagues while being eager to meet his loved ones and people of India. He also quoted a song from the film Swades, which he had chosen as his anthem on the launch day.

Parliament session on India’s space journey

In honour of Shukla’s mission, the Lok Sabha is holding a special session today to discuss “India’s first astronaut aboard the ISS – critical role of space programme for Viksit Bharat by 2047.” Union minister Kiren Rijiju said the discussion would highlight the importance of India’s space achievements and future goals.

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Shubhanshu Shukla pens emotional note as he returns to India after space mission

Indian astronaut Shubhanshu Shukla penned an emotional Instagram post as he returned to India after his 18-day ISS mission, marking a milestone in India’s space journey.

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Indian astronaut Group Captain Shubhanshu Shukla has shared an emotional Instagram post as he heads back home after completing his 18-day mission aboard the International Space Station (ISS).

Astronaut reflects on mixed emotions

In his heartfelt message, written from the aircraft, Shukla expressed the whirlwind of emotions he felt while leaving behind his fellow astronauts, who had been his family during the mission. “As I sit on the plane to come back to India, I have a mix of emotions running through my heart. I feel sad leaving a fantastic group of people behind who were my friends and family for the past year during this mission. I am also excited about meeting all my friends, family and everyone in the country for the first time post mission. I guess this is what life is — everything all at once,” he wrote.

Acknowledges support and inspiration

The astronaut thanked everyone for the love and support he received throughout his journey. He also recalled the words of his commander Peggy Whitson, saying, “Goodbyes are hard, but we need to keep moving in life. As my commander Peggy Whitson fondly says, ‘The only constant in spaceflight is change’. I believe that applies to life as well.”

Shukla ended his note with a line from the song Yun Hi Chala Chal from the film Swades, reflecting his spirit of resilience.

Link to India’s space ambitions

Shukla’s return comes at a crucial time as India advances its space programme. Prime Minister Narendra Modi had earlier mentioned that the astronaut would soon return and that he was tasked with documenting his training and ISS stay. This record will serve as a valuable reference for Gaganyaan, India’s first human spaceflight mission.

Over the past year, Shukla trained extensively at NASA, Axiom, and SpaceX facilities. His flight to the ISS as part of the Axiom 4 mission marked a milestone in India’s preparations for future human space exploration.

The Gaganyaan project aims to send Indian astronauts into orbit aboard an indigenous rocket. The government has also outlined plans for a Bharatiya Antariksh Station by 2035 and a crewed mission to the moon by 2040.

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