While most people You might be drawn to the always-sunny skies, the nearby ocean, or the mountains hugging the Los Angeles Basin, environmental engineer Anne Marie Eldring was drawn to the city’s smog. “It’s the best place to go,” she says. “You have tons of pollution!”
Urban areas emit more than 70 percent of human-made carbon dioxide emissions that end up in the atmosphere, and Los Angeles is no exception. With more than 13 million residents in its largest metropolitan area, a developed network of highways, and an international transportation hub, Los Angeles produces the fifth largest CO22 From all cities of the world. This makes it a good place to study the role humans play in climate change.
Eldering is NASA’s Orbiting Carbon Observatory 3 project scientist, or OCO-3, an instrument that measures carbon dioxide in the atmosphere.2 Levels of space to better understand the impact of human activity on the natural carbon cycle, the process by which plants, soils, oceans and the atmosphere exchange carbon with each other. at Paper published this monthEldering and colleagues released a map showing the most detailed differences for CO2 Emissions over the Los Angeles Basin seen from space. This research demonstrates that space-based monitoring devices can be used to collect large swaths of data on pollution hotspots, information that can help guide policies to combat climate change.
“What’s exciting about the OCO-3 result is that this is the first time we’re getting this kind of area map on a city like Los Angeles from space,” says Joshua Lugner, a postdoctoral scientist at Caltech who works on Global Earth. It is called a المراقبة-based monitoring system Total Carbon Column Monitoring Network. While they are useful for closely monitoring how carbon concentrations in the atmosphere change over time, tools like TCCON are expensive to operate and require partnerships with skilled scientists, so their data collection is limited to specific regions. By contrast, an orbital observatory can survey parts of the planet that are difficult to study from Earth, such as volcanoes or cities with a high carbon footprint but few observational resources.
Launched in 2019, OCO-3 is now installed on the International Space Station, seeing nearly every city on Earth in an average of three days, according to NASA press release. It’s an improvement over its still-active predecessor OCO-2, which can collect a set of data just 10 kilometers wide and lock into a sun-synchronous orbit that passes over Los Angeles at the same time each day, meaning it can only check carbon dioxide in Atmosphere of the city2 Levels at 1:30 pm.
“With OCO-3, we have much better spatial coverage, as well as temporal coverage, because it can now look at the city at different times,” says Caltech postdoctoral scientist Dean Wu, who works closely with the team on emissions analysis. Urban area. OCO-3 can conduct multiple surveys on a single site, mapping approximately 80 square kilometers in less than two minutes.
the color of each pixel This map created by Eldering Team Represents carbon dioxide in the atmosphere2 Concentrations in an area on Earth about 1.3 miles wide. Because carbon dioxide absorbs certain wavelengths of light, scientists can use this information to infer how much is in Earth’s atmosphere. OCO-3 observed changes in the intensity of sunlight as it passed through a vertical column of air and created a reading of the amount of carbon dioxide2 It was in that spot.
The OCO-3 team then compared this satellite data to “clean air” readings already collected by the ground-based TCCON instrument at NASA’s Armstrong Flight Research Center in the desert far north of Los Angeles, far from local emissions sources. Using a baseline of about 410 ppm (or 410 CO2 per million molecules of dry air), OCO-3 was able to determine variations of up to half a part per million. They have seen the peak of carbon dioxide excess2 over five parts per million over the Los Angeles Basin. This may sound small, but it is equal to the amount by which these emissions rise on a global scale every two years.