MICROPHYSICAL AND PHYSICOCHEMICAL CHARACTERIZATION OF ATMOSPHERIC MARINE AND CONTINENTAL AEROSOL AT MACE HEAD

Measurements of the aerosol particle size, aerosol volume distribution and aerosol volatility (diameter range 0.1-3.0 mu m), aerosol mass (d iameter range 0.06-16.0 mu m), condensation nuclei (CN) and cloud cond ensation nuclei (CCN), and black carbon (BC) mass concentration at Mac e Head during the EU project ''Background Maritime Contribution to Atm ospheric Pollution in Europe'' (BMCAPE), obtained over four intensive campaigns during the period between November 1993 and August 1994, are presented. Marine air was found to possess mean accumulation mode (AC M) aerosol particle number concentration., N, of between 100 and 160 c m(-3) for the winter and summer seasons. Marine ACM mass ranged in val ue from about 0.8 to 6 mu g m(-3). Marine air was found to contain bla ck carbon with episodic mean mass concentrations generally in the rang e 5-40 ng m(-3). The impact of black carbon on the marine environment is also reflected by the moderately positive correlation (r(2) in the range 0.23-0.44) found between marine ACM number concentration and BC mass loading, with a higher correlation (r(2) = 0.55) found for winter continental air. Black carbon accounted for between 0.6% and 1.2% of the ACM mass loading for marine aerosol at Mace Head, increasing to be tween 4% and 6% for continental air. Arithmetic mean values of ACM num ber concentration N and BC mass concentration agree quite well with re sults from a few other investigators of marine atmospheric aerosol in the North Atlantic. (C) 1997 Elsevier Science Ltd.