Cooperative Institute for Climate Science

Springtime air pollution from Asia, swept across the Pacific Ocean on winds, can contribute to episodes of high surface ozone pollution in the western United States, according to a new study led by Meiyun Lin from NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL) and the Cooperative Institute for Climate Science - Princeton (CICS-P). The current U.S. air quality standard for ozone is 75 parts per billion. Lin and colleagues from NOAA, NASA, and NCAR found that about half of the times that the threshold was exceeded in parts of California and the Southwest, the Asian contribution added 8 to 15 parts per billion of ozone to air, pushing the already high-level of ozone over the limit. The scientists further reported that satellite data can be used to predict when incoming Asian pollution plumes might affect western air quality, one to three days ahead of time.

Background:
As Asian countries develop, they are emitting more ozone precursors that pollute surface level air. Many studies have shown that powerful spring winds can carry Asian pollution into the atmosphere above North America. The new study goes further, analyzing data collected by satellites, balloon-borne instruments, aircraft, and ground instruments with a global high-resolution chemistry climate model to show how some of the imported pollution can descend into surface air over the western United States. The new paper is published online in the Journal of Geophysical Research – Atmospheres.

Significance:
Exposure to high concentrations of ground-level ozone can cause severe respiratory effects in some people, and it damages crops, trees, and other vegetation. This work relates to NOAA’s Climate Goal: Understand Climate Variability and Change to Enhance Society’s Ability to Plan and Respond.

Contact Information
Name: Meiyun Lin
Tel: (609) 452-6551
Email: meiyunl@princeton.edu