Poor air quality can have a number of adverse effects on human health, and is especially harmful to those with sensitive respiratory systems. Air pollution has many sources both natural (wildfires, volcanoes, dust storms) and man-made (factories, transportation, wood stoves).
While the weather doesn’t produce air pollution, it does influence how concentrated it can get and thus how impactful it is in a certain area. Strong winds will quickly disperse pollutants, but light winds and stagnant air enables the accumulation of enough pollutants to be harmful. New products from the ECMWF’s Copernicus Atmospheric Monitoring Service let you track pollutant concentrations both overall and by specific pollutant type. The thumbnails above give a quick snapshot of current pollutant levels. Click on a thumbnail for a closer look, and the ability to zoom in/toggle forecast time.
Additional features subscribers have access to another tool to monitor possible pollution issues. The Planetary Boundary Layer is the part of the atmosphere that surface air is able to mix with. Basically, pollutants emitted at or near the surface will be dispersed through this layer, but not outside of it. Thus a deep PBL is favorable for good air quality (pollutants can disperse through a large volume of air) while a shallow PBL is favorable for bad air quality (pollutants are trapped in a very small volume, leading to very high pollutant concentrations).
Not all particles in the air are pollutants. Air quality can also be affected by other factors including blowing sand/dust, sea salt aerosols, and organic aerosols. These products measure air quality not in concentration (amount per volume), but rather by the attenuation of incoming solar radiation. What does that mean? Aerosols (particles small enough to be airborne but big enough to see) in sufficient quantities can reflect back into space some of the sunlight that should’ve made it to us here on earth.
This effect is known as “haze” and if you’ve ever experienced or seen videos of wildfires you’ll see how it works. In wildfires, the smoke (aerosols) blocks out the sun, so that areas in/under the smoke plume seem cloudy or even dark despite the fact that there are no clouds and it’s the middle of the day. Of course most haze isn’t that extreme, but it can still be quite impactful (think of the dust storms that shut down roads in Arizona for example).