Variations of Atmospheric Aerosols Inside and Outside Cloud Air

摘要

Aitken Nuclei are present in the size range of 0.001 to 0.1 μm in appreciable concentrations in the continental and maritime environments. The main sources of these nuclei are mainly trace gases and they form out of gas to particle conversion which can occur through the nucleation of aerosol from the supersaturated gases and by the photochemical reactions associated with the absorption of solar radiation by molecules. Gas to particle conversions may be enhanced by high relative humidity and the presence of liquid water. During the summer monsoon months of 1980-1982 warm cloud modification experiment was conducted by IITM at Pune. During this experiment Aitken nuclei observations were made inside and outside the stratocumulus and cumulus clouds at the same altitude during three monsoon seasons. The results of the study suggested that observed higher concentration of Aitken nuclei inside the cloud may be due to more active gas-to-particle conversion process than in the cloud free air.