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Simultaneous airborne measurements of cloud condensation nuclei and sodium‐containing particles over the ocean
Author(s) -
Hobbs P. V.
Publication year - 1971
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49709741302
Subject(s) - cloud condensation nuclei , supersaturation , condensation , atmospheric sciences , sea salt , environmental science , sodium , range (aeronautics) , sea spray , altitude (triangle) , meteorology , chemistry , aerosol , materials science , geology , physics , organic chemistry , composite material , geometry , mathematics
Simultaneous airborne measurements have been made over the Pacific Ocean of the concentrations of cloud condensation nuclei (CCN) active at 0.5 per cent supersaturation and the concentrations and size‐spectra of sodium‐containing particles (SCP) over a wide range of sizes. The concentrations of SCP decreased sharply with increasing height above the ocean and it is likely that most of them originated from the ocean. However, even at altitudes as low as 50 ft above the surface of the ocean, and over surf, the measured concentrations of SCP were only a few per cent of the concentrations of CCN at G.5 per cent supersaturation. Also the average concentrations of CCN did not change significantly with altitude up to at least 10,000 ft. These observations indicate that sea‐salt particles were not the major source of the CCN. It is suggested that the production of sulphates in cloud droplets, followed by the release of these particles when the droplets evaporate, is an important mechanism for increasing the efficiency of CCN in the air.