For the past few days, residents in Phoenix Arizona have been dealing with poor air quality. Stagnant air has led to an increase in particulate matter. Dust and haze have been reducing visibility, and posing health concerns for certain people. Particle pollution is linked to a number of health problems, including coughing, wheezing, asthma attacks, heart attacks, and strokes. The picture below was taken at Noon on Friday. (Photo courtesy of Arizona Department of Environmental Quality).
Particle pollution falls into two categories, fine and coarse. Fine particles, (2.5 micrometers in diameter and smaller), are produced by power plants, industrial plants, vehicle exhaust, wood burning stoves, and wildfires. Coarse particles, (between 2.5 and 10 micrometers), come from crushing and grinding operations, road dust, and agricultural operations. The coarse particle levels exceeded EPA standards on Thursday, and are expected to be high again today. Therefore, Air Quality Alerts have been issued today for south central Arizona, including the Phoenix metro.
Typically, each day, pollutant particles are reduced as temperature inversions break-down, allowing air to rise. Mountain-valley winds circulate air, as surface temperatures heat up. However, the valley air has been rather stagnant this week due to thick cloud cover, which inhibits atmospheric mixing. And in this particular case, there is no rain with the clouds. Rain would help to “knock down” the particles, thereby reducing pollution. So without circulating air patterns or rain, particles are not scoured out, and the pollution carries over to the next day. Today’s air quality index is expected to be near 147. According to the EPA chart below, air is unhealthy for Sensitive Groups, which includes people with heart or lung disease, older adults, children and teenagers.
You can take a few simple steps to reduce your exposure to pollution. Limit your time outdoors, choose less strenuous activities and re-schedule strenuous ones, and spend less time near busy roads.
You can also reduce pollution. Drive less by car pooling, using public transportation, walking and biking. Set your thermostats higher in the summer and lower in the winter. And don’t burn leaves, garbage, plastic, or rubber.
But there is some good news. Better conditions are on the way for Phoenix. Saturday won’t be as cloudy. Sunshine will be able to reach the surface. Surface heating leads to rising air, and this will help reduce the dust and haze a bit. Even more sunshine is on the way for Sunday, along with gentle breezes. Pollution should be reduced even more. And the extended forecast calls for cooler and breezy conditions. That could be the “clearing event” that Phoenix residents are waiting for.
For WeatherNation: Meteorologist Matt Monroe