Hanwant B. Singh

During more than three decades of government service at NASA’s Ames Research Center, Hanwant Singh has advanced our understanding of the changes taking place in the Earth’s atmosphere and climate from both natural causes and human activity.

Singh developed the first instrumentation to decipher important mechanisms of ozone formation in the atmosphere. He discovered a now widely used technique to determine how long many man-made chemicals stay in the atmosphere, took the first measurements of a pesticide that has been phased out due to its toxicity, investigated how deforestation can change air quality thousands of miles away, and has studied how wildfires on one continent can impact atmospheric conditions on another.

“Hanwant Singh is an acknowledged international leader in the area of atmospheric composition and chemistry,” said Eugene Tu, director of the Ames Research Center. “During his 31-year career at NASA, he has conducted major theoretical and experimental investigations in order to understand the Earth’s natural atmosphere and the impact of human activities.”

“He is probably one of the few people who have really significantly distinguished themselves on all sides of it—measurements, analysis and leadership,” added Jack Kaye, an associate director at NASA’s Science Mission Directorate. “He just does it all.”

According to Michael Bicay, director for science at the Ames Research Center, Singh “combines the experimental and theoretical aspects of atmospheric sciences and applies them in a way that benefits society.”

In the 1980s, Singh was one of the key members of the team that measured a number of ozone-depleting substances in the atmosphere. That led to an international agreement to regulate the production of man-made compounds that destroy the ozone layer, the atmospheric protective shield that absorbs more than 90 percent of the sun’s high-frequency ultraviolet light. Depletion of the ozone layer can adversely affect the ecosystem and cause skin cancer, cataracts and other serious health problems.

He took the first measurements of methyl bromide, an agricultural fumigant that depletes the ozone layer and was found to be dangerous to human health.The amount of methyl bromide produced or imported was reduced incrementally until it was phased out in 2005 under an international agreement.

“I think of him more as a renaissance man,” Bicay said. “Hanwant has it all. He plans airborne science campaigns, he measures the data, he builds them into models and the models inform theories into how they work.”

Many of Singh’s studies have used satellites to collect data and airplanes to measure and validate that information. “That gives us a deeper look into what happens,” Singh explained.

Warren Gore, chief of the Ames Research Center, said Singh’s pioneering efforts to understand atmospheric composition allows others to “look at some of the regional problems people face” and “change the way people are thinking.”

Singh and his colleagues, using satellites, found that smoke plumes from wildfires in North America affected areas thousands of miles away. Smoke reached Europe, for example, without significant removal of particles.

Combining satellite data with ground observations and measurements from high-tech aircraft, Singh and his NASA team also tracked smoke from fires in Canada’s Northwest Territories, the Yukon and the three Prairie Provinces—Alberta, Manitoba and Saskatchewan—to better understand the impact on Arctic pollution.

A current study off the coast of West Africa is measuring the impact of wild fires on the atmosphere. As one of the regions of the world where giant cumulous clouds form, this area affects hurricanes and storm systems that travel all the way to the Gulf of Mexico.

“We all breathe the same atmosphere,” Kaye noted. “He helped us understand the chemistry by determining what pollutants form metastable compounds and travel long distances.”

These and other studies have made Singh well known and respected in the international climate science community. “I suspect you say the name Hanwant and everybody in that business will know who you mean,” Bicay said.

But Singh doesn’t seek name recognition, according to Kaye. “It’s about the science, and it’s about making progress,” he said.  

Referring to his body of work, Singh said, “We’re contributing to a cleaner environment and not only making people more aware of the changes that have already occurred, but those that may also occur in the future.”