Most of the US is under lockdown to help limit the spread of the coronavirus, resulting in less human activity outside and dramatically decreasing nitrogen dioxide levels by an ‘unprecedented’ amount.
A new map, created by Earther, highlights the dramatic drop using data from a European Space Agency satellite and shows snapshots of the country from December 2019 through March 20, 2020.
As millions of Americans are no longer driving their cars, levels of nitrogen dioxide – which is formed when fossil fuels are burned – have plummeted.
Powered by Google Earth Engine, the map reveals major metropolitan areas that are home to hundreds of thousands to millions of Americans have experienced an improvement in air quality since the start of the US outbreak.
The two major decreases can be seen over Los Angeles, California and New York City – both have enforced a strict lockdown orders that ask residents to stay home unless travel is absolutely necessary.
The coronavirus started in Wuhan, China December 2019 and has since spread to more than 168 countries across the globe.
The death toll has now exceeded 15,000 and the number of cases worldwide has soared past 348,000 – with more than 43,000 cases and over 500 deaths reported in the US.
US officials have begun setting strict rules for their states as of this month, by banning social gatherings, implementing curfews and closing non-essential businesses until further notice.
And these stay-at-home policies and lockdowns across the country have dramatically reduced the amount of pollution in the air.
The map, created by Earther, is powered by Google Earth Engine and pulls data from the European Space Agency’s Sentinel-5P satellite.
The satellite is capable of capturing the nitrogen dioxide levels over the Earth, which is released into the air from burning fossil fuels.
Nitrogen dioxide is known to increase respiratory problems, as it inflames the lining of the lungs and reduces the person’s ability to fight off lung infections.
It also causes wheezing, coughing, colds, flu and bronchitis, and is linked to asthma.
California was the first to implement a stay-at-home policy earlier this month, with Governor Gavin Newsom deeming socializing outside of the home a crime until further notice.
The state’s drop in nitrogen dioxide began shortly after the policy went into effect, with Los Angeles, a pollution hub, experiencing the largest decrease.
The Bay Area and San Diego have also witnessed an improvement in their air quality.
The Northeast Corridor, which stretches from Washington DC to Boston, Massachusetts, is home to some 56 million people and is usually heavy with nitrogen dioxide.
However, it is also an area where officials were quick to impose a shutdown of non-essential travel and businesses.
In New York City, all nonessential gatherings of any size are temporarily banned and many businesses have been forced to suspend their operations.
The Big Apple has been deemed a hotspot of the virus and although it does not rely heavily on automobile traffic like Los Angles, New York City has also seen a drop in air pollution since the lockdown began.
Researchers at Columbia University have seen emissions of carbon monoxide over New York City decline more than 50 percent below typical levels over the past week.
Levels of carbon dioxide have dropped by up to 10 percent and methane have also fallen ‘significantly’, according to the Colombia team.
The rest of the major cities, including Boston, Philadelphia, Baltimore and Washington, usually form a daisy chain of pollution along Interstate 95, but, according to Earther, it has been broken since the areas mandated lockdowns.
In the Midwest, which consists of areas from Minnesota to West Virginia, sits the largest cluster of states in lockdown.
Currently six of them have asked residents to only leave for essential travel and more are expected to follow in the next coming days.
The map shows a dramatic decrease in pollution over Chicago, which is home to 2.7 million people.
Although many of the southern states have yet to implement stay-at-home policies, it seems residents are taking matters into their own hands.
Areas over Houston, Texas have seen an improvement in air quality, as well as New Orleans which is the only southern state to impose a total lockdown.
Earlier this month NASA and the European Space Agency released a separate set of satellite images that showed a dramatic reduction in the amount of harmful greenhouse gas emissions over China.
Researchers from Stanford University say in places like China the reduction in air pollution has led to fewer premature deaths from breathing toxic air.
The improved air quality around the world isn’t likely to remain long term though, as scientists warn things will likely ‘return to normal levels’ when industry resumes.