Meteorological differences between NEAQS 2002 and ICARTT/NEAQS 2004

During the New England Air Quality Study (NEAQS) of July-August 2002, there were a significant number of days with elevated levels of ozone. As part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) summer 2004 campaign, there was a second NEAQS program. However, during this latter study there were remarkably fewer elevated pollution days in New England. This paper will present some preliminary findings on the meteorological differences that led to the contrasting air quality outcomes encountered during these summers.

Maximum temperatures and flow trajectories are certainly major factors in setting the necessary conditions needed for ozone formation. However, cloud cover, precipitation events and longevity of flow regimes also help to play an important role in determining the severity of pollution events. These differences will be illustrated by comparing the summer climatology of 2002 versus that of 2004.