Phosphine in the marine atmosphere along a hemispheric course from China to Antarctica

Abstract

The gas phosphine (PH 3) is a part of an atmospheric link of the phosphorus cycle on earth. Previous research reported the terrestrial lower tropospheric PH 3 at night in the 1 ng m −3 range in remote areas, with the peak of 100 ng m −3 in populated areas, and at daytime even lower concentrations in the pg m −3 range. The data of the global marine atmospheric PH 3 are still very sparse. This study presents surprisingly high concentrations of PH 3 in the order of 0.1–1 μg m −3 in many of 32 samples of the marine atmosphere in the latitudinal range from 30°N to 65°S (the cruise of research ship Xuelong from Shanghai Harbor, China, to Antarctica). The highest concentrations were measured near coastal areas of Eastern Asia and Western Australia. A significant correlation exists between marine atmospheric PH 3 concentration and air temperature at 22:00 (local time). PH 3 concentrations at different latitudes strongly decline with daylight intensity according to a logarithmic relationship. These surprisingly high concentrations of the readily oxidizable PH 3 in the air indicate hitherto unknown but important PH 3 emission sources in marine environment. More work is necessary to evaluate the sources of atmospheric PH 3 from marine biosphere.