Now in the map menu click on “Vertically Integrated Smoke”. Instead of measuring smoke about eight meters above the ground, he models what an air column 25 kilometers high looks like at a given location in the United States. (Think of it as the smoke you can see in the sky, versus the near-surface smoke being what you actually breathe.) As you can see, at this scale, smoke now covers most of the area. country.
To map this, HRRR considers the infrared intensity of these fires and projects the amount of smoke that a fire produces. This smoke comes from the eddies of what atmospheric scientists call the boundary layer. “This is the layer through which you feel the bumps when you land on a plane in the late afternoon anywhere in the country,” says Benjamin. “But then some of that air mixes up higher above the boundary layer, and then it meets stronger horizontal winds.” It carries the smoke from west to east.
And as that smoky air moves across the country, Benjamin adds, “it gets mixed up because of this turbulent mixing that takes place during the day. And that’s how you collect some of it now near the surface.
Click the “Smoke near the surface” option again, and you can see that only a small fraction of these smoke particles actually fall out of the atmosphere and reach the ground on the east coast. Unlike the people of the Bay Area, you don’t have to worry if you’re in New York or Philadelphia. “It’s orders of magnitude of difference,” Benjamin, the unfortunate Californian told me. “You get creamed.”
But even though HRRR is still experimental, it quickly became an essential tool for meteorologists and atmospheric scientists, as no one had been able to predict clouds of smoke like this before. Previously, researchers had just looked at satellite images to see where the smoke currently is. “This is truly the first resource in existence that tells you where the smoke you see and where it is coming from and what to expect,” says Joost de Gouw, atmospheric scientist, Cooperative Research Institute for Environmental Sciences. from the University of Colorado, Boulder.
This helped de Gouw plan his experiments, in which he takes atmospheric measurements on airplanes to study how smoke changes chemically as it moves through the air. If he knows where the smoke is going, he knows where to take samples. “Most people, when they think of smoke, think of smoke particles,” de Gouw says. “But also a lot of gases accompany the smoke, and a lot of these gases are highly reactive – they change on a time scale of a few hours.”