Variations in cloud condensation nuclei at palmer station antarctica during february 1994

Cloud Condensation Nuclei (CCN) activity spectra and meteorological data were measured between February 12 and February 26, 1994 at Palmer Station, Antarctica. The CCN concentrations (at ≈ 1.3% supersaturation) ranged from < 1 to 700 cm−3 with an average of 20 cm−3. The lower CCN concentrations were measured during fog, precipitation, or fogless periods following widespread precipitation. The higher CCN concentrations were observed in the vicinity of virga and evaporating low level clouds, as well as during pollution episodes. The CCN spectra were typical of a marine location. The meteorological and CCN spectral data indicate a significant change in the total CCN concentration measured in association with the sampling near the fog-free boundary of different air-masses or air-parcels, including those from evaporating clouds.