Aquatic cycling and hydrosphere to troposphere transport of reduced trace gases — A review

Abstract

A review of recent literature on the transport and cycling of the reduced trace gases ammonia, hydrogen, methane and volatile sulfur gases is provided in this paper. Greater concentrations of these gases are usually observed in the anaerobic (oxygen-deficient) environment, but they are not necessarily limited to these habitats. Many are gaseous endproducts of the microbial processing of labile organic matter. They are also involved in oxidation/reduction reactions and the transferring of energy across cellular and environmental interfaces. Some of these reduced gases have been intensively studied in the past decades because of their importance to tropo- spheric changes in climate as RIT (radiatively important trace) gases and their involvement in atmospheric chemistry. Because of increased interest and funding for research in the area of climate change, and an expanding level of publications, this review might already be out- of-date as it reaches the readership.