News and Articles

Temperature inversions

Posted on January 10, 2023
Courtesy of The Weather Network

 

Typically, warm air sits near the ground, and air rises easily, carrying away polluting substances. During a temperature inversion, cold air is trapped near the ground by warm air several hundred meters above it. The warm air acts like a lid, and polluting substances can’t rise and disperse as readily. As a result, a higher AQHI rating is realized.  

The AQHI is a tool that helps people understand what the local outside air quality means to their health. Moderate to high AQHI ratings may lead to health problems for at-risk populations, such as children, the elderly and those with pre-existing respiratory conditions. 

Some sources of polluting substances, like industrial emissions and wetlands, stay fairly constant throughout the year, no matter the season. But in the winter, fireplaces, wood stoves, home heating and idling vehicles contribute to higher concentrations. A temperature inversion traps a build-up of these substances near the ground until wind, a snowstorm, or some other weather change sweeps them away.

Fortunately, temperature inversions that cause high or very high AQHI ratings don’t happen very often. Fort Air Partnership (FAP), the organization that monitors the air people breathe in and around Alberta’s Industrial Heartland, reported only 133 hours of high or very high AQHI ratings throughout 2022. Although it is challenging to determine precisely how many of these hours were due to wintertime temperature inversion, FAP estimates it is about 5%. The majority of exceedances are due to wildfire smoke.

What you can do

People can reduce their impact on air quality by not idling vehicles when parked, avoiding excessive fireplace or wood stove use, and using energy-efficient products. People can also keep track of current and forecast local AQHI levels on the FAP website, and if levels are high, adjust their outdoor activities accordingly. You can also follow FAP on Facebook, Instagram, and Twitter.

Report on Town of Lamont Portable Air Monitoring Results

Posted on January 5, 2023

Fort Air Partnership (FAP) collected air quality measurements from a portable air monitoring station in the Town of Lamont from August 1, 2021, to August 31, 2022. Data collected during the 13-month Town of Lamont project was used to calculate an Air Quality Health Index (AQHI), as is done at other community stations within FAP.

Results
The results indicate that the air quality the Town of Lamont residents experience is of low risk 98.4 percent of the time. This is a slightly higher percentage than the four other FAP community stations used for comparison in the report.

Less than 1.5 percent of the time, AQHI was recorded in the moderate risk category. There were six hours of high risk AQHI recorded due to smoke from wildfires outside of FAP, and no instances of very high risk AQHI were recorded.

Regional events such as wildfires and wintertime temperature inversions affected air quality in the Town of Lamont, similarly to other communities throughout the FAP region. Five such events occurred during the reporting period, all due to wildfire smoke. The small number of air quality events monitored during the project was not enough to definitively compare the influence of regional events on the Town of Lamont relative to other communities in FAP.

Read the full report.