Observation of the Variations of Very Short-Lived Halocarbon Emissions in Tropical Coastal Marine Boundary Layer

Abstract

Halocarbons (methyl iodide, bromoform and dibromomethane) are produced naturally and the source has been found to be largely from the ocean. In recent years, the role of very short-lived halocarbons in the atmospheric chemistry has attracted many researchers in this field. Dissolved halocarbons in sea water and atmospheric halocarbons were taken at 73 different positions across South China Sea and Sulu Sea during the SHIVA measurement campaign on RV SONNE cruise from Singapore to Manila on the 15 to 29 November 2011. Both water and canister samples of air were analyzed on two different purge-and-trap (PT) gas chromatographic systems. Significant levels of halocarbons were observed during day-time and night-time in the tropical marine boundary layer. All of the halocarbons show higher concentrations at the coastal area compare to the location in the open sea.