CONTRIBUTION OF PARTICULATE SULFATE AND ORGANIC-CARBON TO CLOUD CONDENSATION NUCLEI IN THE MARINE ATMOSPHERE

To identify the source of cloud condensation nuclei(CCN) in the marine atmosphere, simultaneous measurements of aerosol chemical components and CCN concentration were made over more than a year at Hahajima, the Ogasawara Islands, located on the Northwest Pacific Ocean in the lee of Eastern Asian large pollution sources. Large loading of CCN in cont inental air mass and long-distance transportation to the remote ocean were confirmed. Non-seasalt sulfate and water soluble organic carbon w ere dominant in fine aerosols and their concentration revealed signifi cant relationships with CCN concentration, suggesting that not only su lfate but also organic aerosols play a key role in CCN formation, espe cially in the background atmospheric condition.