Ever wonder how the western US has high ozone levels when the winds usually blow in off the Pacific Ocean? Did you think it was all from the cars clogging the freeways? Turns out, it is caused in part from emissions of ozone generating air pollutants from Asia.
A study by the National Oceanic and Atmospheric Administration (NOAA) shows that Springtime ozone levels above western North America are rising, primarily due to air flowing eastward from the Pacific Ocean, a trend that is most significant when the air originates in Asia. These increases in ozone could make it more difficult for the United States to meet Clean Air Act standards for ozone pollution at ground level, according to a new international study published online Jan. 20 in the journal Nature.