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Increase green cover to mitigate urban heat : NASA

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By NewsGram Staff Writer

Washington:  Providing a solution to the recent problem of rising urban heat, a recently conducted study by NASA explained how increasing the green cover can help cities to a great extent.

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Using multiple satellites’ observations, researchers found that areas in the US covered in part by concrete surfaces had a summer temperature 1.9 degrees Celsius higher than surrounding rural areas.

In winter, the temperature difference was 1.5 degrees Celsius higher in urban areas.

At the human level, a rise of one degrees Celsius can raise energy demands for air conditioning in the summer from five to 20 percent.

“This has nothing to do with greenhouse gas emissions. It is in addition to the greenhouse gas effect. This is the land use component only,” said Lahouari Bounoua, research scientist at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland.

The urban heat island effect occurs primarily during the day when urban impervious surfaces absorb more solar radiation than the surrounding vegetated areas, resulting in a few degrees temperature difference.

The urban area has also lost the trees and vegetation that naturally cool the air.

“Anywhere in the US, small cities generate less heat than mega-cities,” Bounoua said.

The reason is the effect vegetation has on keeping a lid on rising temperatures.

“The amount and type of vegetation plays a big role in how much the urbanisation changes the temperature,” added research scientist and co-author Kurtis Thome.

As a by-product of photosynthesis, leaves release water back into the atmosphere in a process called evapotranspiration, which cools the local surface temperature the same way that sweat evaporating off a person’s skin cools them off.

Trees with broad leaves have more pores to exchange water than trees with needles, and so have more of a cooling effect.

“So even though 0.3 degrees Celcius may seem like a small difference, it still may have impact on energy use,” Bounoua said, especially when urban heat island effects are exacerbated by global temperature rises due to climate change.

Understanding the tradeoffs between urban surfaces and vegetation may help city planners in the future mitigate some of the heating effects, the authors noted in a paper that appeared in the journal Environmental Research Letters.

(With inputs from IANS)

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NASA’s Planet-Hunting Telescope Lifts Off In U.S.

Rocket with planet-hunting telescope finally lifts off

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NASA's next mission.
TESS, the Transiting Exoplanet Survey Satellite, is shown in this conceptual illustration obtained by Reuters on March 28, 2018. NASA sent TESS into orbit from the Kennedy Space Center in Florida aboard a SpaceX Falcon 9 rocket April 18, 2018, on a two-year mission. VOA

A Falcon 9 rocket blasted off Wednesday carrying SpaceX’s first high-priority science mission for NASA, a planet-hunting space telescope whose launch had been delayed for two days by a rocket-guidance glitch.

The Transit Exoplanet Survey Satellite, or TESS, lifted off from Florida’s Cape Canaveral Air Force Station at 6:51 p.m. EDT, starting the clock on a two-year quest to detect more worlds circling stars beyond our solar system that might harbor life.

The main-stage booster successfully separated from the upper stage of the rocket and headed back to Earth on a self-guided return flight to an unmanned landing vessel floating in the Atlantic.

Also Read: Why NASA sent human sperm to space?

The first stage, which can be recycled for future flights, then landed safely on the ocean platform, according to SpaceX launch team announcers on NASA TV.

Liftoff followed a postponement forced by a technical glitch in the rocket’s guidance-control system.  VOA

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