Satellite images of Las Vegas show just how extreme urban heat islands can get

Satellite images of Las Vegas show just how extreme urban heat islands can get thumbnail
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Summer in the southwest US is already scorching. Since June 9, Las Vegas, Nevada has been trapped in a Heat Dome ,. This is an atmospheric pressure cooker that superheats the air near the ground. The area was hit with record-breaking heat, with temperatures reaching triple digits. On June 10, 2022, the city reached a record daily high of 109 degrees Fahrenheit–so hot that the heat was picked up by sensors in space.

NASA’s Ecosystem Spaceborne thermal Radiometer Experiment at Space Station, or Ecostress generated a map showing the land surface temperatures in Las Vegas and the surrounding area. Recorded at 5: 23 pm when heat peaked, the map reveals it radiating out from the city center from red to yellow.

[Related: A ‘heat dome’ is searing the US with record-breaking temperatures. ]

This map shows the stark effects of the “urban heat islands” effect. It magnifies the dangers posed by extreme heat in cities. The heat from human activity, vehicles, buildings, and streets absorbs more heat than areas with less vegetation and more development.

“Even in a place like Las Vegas, which is in the desert, and there’s low tree canopy cover in the first place, you can see that places where there are less trees are hotter,” says Chris David, vice president of data and mapping at American Forests, which did a survey of tree canopy and vulnerability to heat in American cities in 2021.

Explore data on tree cover, heat islands, and “tree equity” in Las Vegas in American Forests’ tool below:

The Ecostress project was created to monitor water loss from plants under warming conditions. It also provides street-level views of heat waves. Because it is typically hotter on the surface, the instruments aboard the International Space Station target ground temperature more than air temperature. This is reflected in the map’s darker red grid pattern–pavement temperatures even exceeding a broiling 122 degrees Fahrenheit.

” This is basically a Las Vegas streetmap,” says David. Asphalt absorbs up to 95 percent of solar radiation, which means that the material emits additional heat at ground level where people are walking and living, he explains. “It’s important that people have shade .”

when they are outside.

Other regions in the US have also been bombarded with blistering heat . Excessive heat warnings and heat advisories have impacted more than 95 million people from the southwest to Florida to northern Michigan, according to the Washington Post. “We all know that when flash flooding or thunderstorms or hurricanes are coming, we better take care of ourselves,” Erick Bandala, assistant research professor of environmental science at the Desert Research Institute in Las Vegas, told the Washington Post. “But it’s not about extreme heat. It’s one of the most overlooked risks .”

As climate change brings more frequent and more intense heat waves, heat-related injuries and deaths are a growing concern, and especially afflict low-income and minority communities. People of color are more likely to live in hotter cities with urban heat islands (sometimes up to 20 degrees Fahrenheit hotter than communities of predominantly white high-income residents), and therefore wrestle with issues brought by heat.

“This is part the history of redlining in America–sticking poor people and people of color in neighborhoods that are right by the highway, which have poorer air quality and higher levels of impervious surfaces, higher temperatures.” says David.

Last year, a similar heat dome settled over Washington, Oregon, and British Columbia, killing hundreds as temperatures rose to nearly 110 degrees Fahrenheit. During that heat wave, deaths in Portland were concentrated in neighborhoods with lots of asphalt, and few trees. David states, “It just shows that trees can be life- or death infrastructure.”

Philip Kiefer

Lauren J. Young

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