During August 1982 and January and February 1983, General Motors Research Laboratories operated an air monitoring site on the southwest coast of Bermuda The data show that the levels of the NO, and SO, species reaching Bermuda are determined by the direction of the air flow. The highest levels ofsulfate (mean = 4.0~gm-'), nitric acid (126ppt) and other species are observed when air masses arrive from the northeastern United States while the lowest Jevels (sulfate = 1.1 pgme3; nitric acid = 41 ppt) occur during air flow from the SE direction. With westerly air flow, increases in many ~thro~gcn~ constituents such as particulate sulfate, lead, elementat carbon, sulfur dioxide, nitrogen dioxide, nitric acid and oxone are observed. These species are generally the iowest during SE winds which bring high concentrations of so& and crustal-related aerosol species. The source of this nustal material appears to be the Sahara ken.On the average, the levels of anthropogenic constituents are higher in winter because of frequent intrusions of N American air masses, Conversely, the levels of crustal materials are higher in summer when the SE flow is more prevalent. Key word index: Aerosols, Rermuda, carbonaceous aerosols, crustal aerosols, fine particles, long-range transport, nitrogen oxides, sulfur oxides, trace metals.
I. I~TRODU~IONTo understand the fate of anthropogenic air potlutants, the atmospheric life cycles or budgets of the various species must be known. This includes understanding the pollutant sources, sinks, transport characteristics, and chemical transformations. Two of the more extensively studied budgets are the SO, and NO, budgets for eastern N. America (Galloway and Whelpdale, 1980; Galloway et al., 1984;Logan, 1983). Even these budgets, however, have large uncertainties associated with various terms and they either ignore or inadequately deal with atmospheric transformations. One reason for these un~rt~nties is the lack of data on the concentrations of key species in certain geographical areas. To obtain some of these data, Genera1 Motors Research Laboratories (GMRL) participated in an intensive experiment which was part of the Western Atlantic Ocean Experiment (WATOX).During August 1982 and January-February 1983, GMRL operated sites near the Atlantic Coast in Lewes, DE (Wolff et ol., 1986), and on the island of Bermuda. The Lewes site served to obtain data on air masses leaving the eastern United States while the Bermuda site served as a downwind receptor site. The
