Cities across the globe have seen a positive change in air quality as social distancing and self-isolation means fewer cars on the road.

Arizona is one of the areas seeing a difference in pollution levels.

While cloudy and rainy weather in March made it more difficult for air quality experts to note changes, studies show a decrease — like a 28% reduction in nitrogen dioxide compared to last year.

Ron Pope is a climate scientist with the Maricopa Air Quality Department. He and his team are analyzing data from air contaminant trends throughout March and early April.

"We're seeing it with the traffic pollutants — so the pollutants that are directly emitted by vehicles," Pope said. "So, P.M. 2.5 and nitrogen dioxide — these are our pollutants that seem to be most impacted after the shutdown.”

Pope notes that a variety of factors can determine how we may see additional changes in air quality over the coming months.

These range from temperature and sunlight to weather and wind patterns.