VARIATIONS IN-CLOUD CONDENSATION NUCLEI AT PALMER STATION ANTARCTICA DURING FEBRUARY 1994

Cloud Condensation Nuclei (CCN) activity spectra and meteorological da ta were measured between February 12 and February 26, 1994 at Palmer S tation, Antarctica. The CCN concentrations (at approximate to 1.3% sup ersaturation) ranged from < 1 to 700 cm(-3) with an average of 20 cm(- 3) The lower CCN concentrations were measured during fog, precipitatio n, or fogless periods following widespread precipitation. The higher C CN concentrations were observed in the vicinity of virga and evaporati ng low level clouds, as well as during pollution episodes. The CCN spe ctra were typical of a marine location. The meteorological and CCN spe ctral data indicate a significant change in the total CCN concentratio n measured in association with the sampling near the fog-free boundary of different air-masses or air-parcels, including those from evaporat ing clouds.