Trinidad Head, California: New NOAA/CMDL Baseline Observatory for Monitoring Asian Atmospheric Effluents

Long-range transport of dust and air pollution from Asia to the Mauna Loa, Hawaii, Atmospheric Baseline Observatory has been documented since the early 1970s. In a single year, as many as 30 distinct pollution flow events from Asia have been observed there. Some flows last a few hours, whereas others persist for up to 5 days. More recently, it has been recognized by both measurements and satellite photos that there are significant numbers of air pollution flow events from Asia into North America along a broad front, ranging from the north slope of Alaska to central California. There is a valid concern that ozone and ozone precursors advecting from Asia could eventually put California into noncompliance with federal air-quality regulations. As a component of the Intercontinental Transport and Chemical Transformation (ITCT) program, NOAA/CMDL established an atmospheric monitoring observatory (April 2002) at Trinidad Head, California in collaboration with Humboldt State University, to monitor both the inflow of air pollution from Asia as well as regionally influenced air. The station monitors aerosols, ozone (continuous surface and weekly ozonesonde balloon profiles), radiation, and halocarbon and carbon cycle trace gases (weekly flasks). Data from Trinidad Head are monitored via the internet at CMDL in Boulder. Plans call for the installation of a GC/MS for the measurement of PAN, hydrocarbons, and certain halocarbons, and for vertical profiles of trace gases and ozone to be obtained (with light aircraft) upwind and above the site on a weekly basis. It is expected that the Trinidad Head observatory will expand measurement programs over the next 5 years and be in operation for many decades to come.