Courtesy of Shotzr, Photo by Nick Brattin (@nickbr)
Satellite images are showing that areas in big cities, like Denver, are seeing lessened air pollution with fewer businesses open and cars on the roads.
With the current crisis of a pandemic looming over our heads, people are searching for any kind of positive light to see. Thankfully, air quality levels have been lower, which has led to vision not being impaired by smog and other pollutants.
Like a science experiment in high school or college, we had a « normal » and then we changed our normal. Now comes the fact in determining the outcome. COVID-19 has been a very scary crisis to live through and experience first hand.
Satellite images from before and after cities, states, and countries under lockdowns have captured some stunning imagery of air pollution. On a normal day, there’s no way to recreate the effects from a complete shutdown of a major city with millions of inhabitants other than computer modeling, but scientists around the world have the opportunity to see real-time effects of cities and states being shut down.
You may have seen these images come across your social platforms recently as this imagery show drastic changes and proves that with some effort, we can curb our effects on the environment and become more aware of our individual impacts.
New #NO2 map available for #Italy– based on data from @CopernicusEU #Sentinel5P and processed by @KNMI/@esa.
🛰️images show nitrogen dioxide concentrations from 14 to 25 March 2020, compared to the monthly average of concentrations from 2019.
Read more: https://t.co/0gXGSaJAed pic.twitter.com/UCV6RN0C0U
— ESA EarthObservation (@ESA_EO) March 27, 2020
It’s clear that China, France, and Italy are showing large drops in air pollution during the COVID-19 pandemic. Most of what you’re seeing are changes in Nitrogen Dioxide (NO2), which is dubbed and atmospheric pollutants emitted by a combustion process and has a short lifetime of less than one day.
While we can see a clear representation that there are fewer pollutants in the air, it’s hard to say whether that’s a direct result of the virus or other factors likes the winds and the temperatures. Those two have a big impact on how the pollutants are concentrated and dispersed. Another note, satellites (which are above the clouds) tend to have a hard time seeing perfectly through the clouds. So there are plenty of reasons why these images need to be dissected more by scientists.
The operators of the satellite mission known as Copernicus even wrote an article called « Flawed estimates of the effects of lockdown measures on air quality from satellite observations, » explaining how pixel resolution interpreted by the satellite requires further analysis by expert scientists to make a final statement about how much impact is a result of the virus shutdowns.
Traffic and pollution levels across the U.S. have dropped amid the #COVIDoutbreak. @DescartesLabs processed data from #Sentinel-5P satellite and compared it to March 10-22 of last year. Here’s what they found: pic.twitter.com/DTk2QSRjLy
— Pattrn (@pattrn) March 24, 2020
Air Quality Impacts on Denver
Is the stay-at-home order in Denver currently impacting our air quality? Understanding the simple concept that if you have less traffic, you have fewer pollutants and that right there is your simple answer.
A more complex answer will take into account traffic patterns and weather patterns. While a stay-at-home order is in place currently, trucking and deliveries are continuing and traffic has been reduced slightly.
One of the main pollutants on the Front Range is ground ozone. That’s created when sunlight cooks greenhouse gasses, like NO2, into different pollutants. Right now, the days are shorter than the days in the summer and that will have an effect on the outcome as well. We typically begin to see more intense air quality issues in June. Springtime is when Denver normally has some of its best air quality of the year.
While we continue to stay home, just know that it’s having an impact on the air quality, but to what extent is currently unknown.