SEASONAL EVOLUTION OF BROMOMETHANES FROM CORALLINE ALGAE (CORALLINACEAE) AND ITS EFFECT ON ATMOSPHERIC OZONE

Coralline algae (Corallinaceae), which are widely distributed throughout the coastal areas in the world, are known to contain a high level of bromoperoxidase. We have revealed that coralline algae generate bromoform (CHBr3), dibromomethane (CH2Br2) and dibromochloromethane (CHClBr2); the total mass of bromomethanes was estimated to be 7,400 ton per year. Evolution rates of these compounds clearly correlate to the bromoperoxidase activities in the algae, and they are released in the air from February to March of each year. These findings explain why the high level of bromomethanes in the Arctic troposphere occurs only during late winter and the early part of spring each year. In this article, we discuss the effect of concentrated inputs of bromomethanes from algae on ozone in the Arctic troposphere.