Yucky air: China, India have us beat
A relatively strong ridge of high pressure has been locked in over North Idaho and the rest of the Far West, leading to very stagnant air and smoggy conditions. During these types of patterns, pollution will often increase, especially in the lower elevations where the air becomes trapped.
As a result, the National Weather Service will often issue an “Air Stagnation Advisory” until the ridge weakens and allows more wind movement to help clean out the polluted air.
With an Air Stagnation Advisory, “pollution has the potential to increase to dangerous levels.”
The National Weather Service recommends, “People with respiratory illness should follow their physician’s advice for dealing with high levels of air pollution during periods of stagnant air. State air quality agencies highly recommend that no outdoor burning occur and that residential wood burning devices be limited as much as possible. According to state air quality agencies, prolonged periods of stagnant air can hold pollutants close to the ground where people live and breathe. Check with your local burn agency for any current restrictions in your area.”
With very little air movement, air pollution levels in Coeur d’Alene and surrounding regions have been rising into the “moderate” category this month, levels between 50 and 100. There was a brief period last Sunday, Nov. 3, that we did get into the “Unhealthy for Sensitive Groups” category as the figure hit 103.
The Air Quality Index is based on the measurement of particulate matter that includes ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide emissions. With long periods of stagnant conditions, these pollutants often build up and can lead to a number of health issues such as coughing, throat irritation and congestion. It can also reduce lung function and long exposure can scar lung tissue.
Some of the worst air pollution levels have been found in India over the past month. The smog has been so thick that one could easily see the toxic haze of gray and yellow over the region. The city of Delhi is considered to be one of the world’s most polluted cities. The pollution over the last month has been so bad that public health emergencies were declared, closing schools and canceling flights.
The wave of severe air pollution has sent Air Quality Indexes over 400, which is in the hazardous or severe category, across many cities of North India. On Oct. 31, the city of Ghaziabad in northern India had an index of 482.
India and China have the world’s most polluted cities for long-term pollution. According to the World Health Organization, eight of the top 10 most-polluted cities in the world are in India. Nearly half of the top 50 most polluted cities are in China. And, not one U.S. city was listed in the top 50.
As I mentioned in an article early this year, for “short-term” particle pollution, most of the major California cities were in the top 7. They included Bakersfield, Fresno, San Jose and San Francisco. Missoula, Mont., was No. 5 and Yakima, Wash., was sixth. The Spokane and Coeur d’Alene area was tied with Sacramento at No. 15.
Here in the Inland Northwest, pollution levels are generally low as we have averaged over 250 days with very good air quality over the last 5 years. However, we do get long stretches with dry and stagnant conditions that increase the levels of bad air, but the smoke from the large wildfires has been the primary reason for poor air quality. In 2017, air quality in the region was not only the worst in the country on that date, but perhaps the worst in history here in Coeur d’Alene. On Labor Day, Sept. 4, air quality levels hit an unbelievable 303, which is in the “hazardous” category. By the way, we do feature the air quality forecast on the front page each day.
In terms of our local weather, there may be a few rain showers around this week, but we should see more stagnant air as the big high pressure ridge over the western U.S. continues to dominate our weather patterns. However, unseasonably frigid temperatures are plunging down into the nation’s midsection as lows have been below freezing all the way down into northern Texas.
Eventually, the high pressure system over the West will move to the east and allow stronger storms from the Pacific Ocean to move into the region. Therefore, we should see some showers next week, and Cliff and I do see moisture increasing across the Inland Northwest with rain and mountain snows around the last week of the month. It’s also possible that the air will be cold enough to produce more snow in the lower elevations. We should also see more moisture in December as well.
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Contact Randy Mann at randy@longrangeweather.com