Variability of Sulfate Aerosol Concentrations at Mauna Loa Observatory, Hawaii

摘要

Daily total particulate matter observations of sulfate, sodium, and methanesulfonate were collected at Mauna Loa Observatory (19.54°N, 155.57°W, 3397m ASL) during 1995-2008. Observations were restricted to nighttime, downslope conditions and were thus representative of free tropospheric air masses. In this paper we focus analyses on 2008, when active volcanoes in Hawaii, Alaska, Indonesia, and elsewhere may have perturbed the northern hemisphere sulfur budget. The 2008 seasonal cycle of aerosol species was broadly consistent with the 1995-2008 mean, although the springtime peaks of anthropogenically-derived sulfate were larger than typical. Trajectories originated from East Asia less frequently and from North America more frequently in spring 2008 than in the long term data record, possibly linked to the strong La Nina conditions that year.