Greenhouse Gas Research Group
Investigation of the
Southern Methane Anomaly: causes, implications, and relevance to past global
Methane is the second most important greenhouse gas and
contributes to the atmospheric chemistry affecting ozone. Southern tropical methane sources and sinks
constitute a significant component of the global methane budget. The current
major anomaly in southern methane growth rate is among the largest on record.
Yet despite its importance, tropical methane variability has received
relatively little study. This proposal is to investigate the southern tropical
methane budget. The work will improve quantification of southern tropical
sources and the understanding of the mechanisms of sudden growth events.
The project will focus on the measurement of methane in the
southern tropics, carrying out campaign studies, especially on Ascension, and
modelling the results. Measurement will include continuous measurement by CRDS
in Ascension, E. Falklands, bi-annual Atlantic transects by RRS JC Ross, and
Tedlar bag sample collection for CH4 and δ13C of CH4
in Uganda, Peru and Bolivia. Campaign studies will include installation of a
CRDS instrument in Peru and use of an unmanned aerial system (UAV) to sample
above the Trade Wind Inversion on Ascension, as well as source campaigns to
characterise δ13C signatures of CH4 emissions in Africa
and S. America.