Our Pollution Is Trapped During The Cold Season
Thursday, December 19th, 2013 — I am sure you have noticed a smoky, light brown haze hanging over our city the past few days. In fact this morning this dirty cloud was at its thickest. This is one of the less attractive, but still important aspects of our cold season weather that hangs over El Paso and Juarez. This is an unwelcome phenomenon that is a direct result of our population growth in the two cities and stable cold air at the surface. Just think of the impact of thousands of motorized vehicles, trains, planes, along with industry and home fireplaces, releasing billions of particles into the air. These minute bits of pollution swirl around in our atmosphere on a daily basis, but under certain weather conditions, they are trapped over the metro area and build up over a period of days. The best (or worse) case scenario for the light brown haze is a combination of light upper level winds and cold temperatures at the surface, which is called an “inversion”. Under these circumstances, the cold air at the ground level is heavy and stable, minimizing the mixing of the air. The light winds aloft mean little change will occur in the overall pattern and no major weather systems on the way. Day after day the air fills with more pollution and the light brown haze or smoky fog “smog” grows thicker.
Looking back at history, this haze is nothing new. The Native Americans told the pioneers and early settlers about a brown cloud that developed from their campfires during the cold season.
Good news for clearing out the skies! A low pressure system with a cold front will blow in this weekend kicking up both the surface and upper level winds. This system also carries in scattered rain showers and mountain snow. This should clear us out for a few days until the next stable weather pattern allows an “inversion” to trap our pollution.