HR: 1330h
AN: GC12A-0150    [PDF]
TI: Global estimates of the oceanic emission of dimethylsulfide under enhanced greenhouse conditions
AU: * Gabric, A J
EM: a.gabric@griffith.edu.au
AF: Faculty of Environmental Sciences, Griffith University, Nathan, Qld 4111 Australia
AU: Simo, R
EM: rsimo@cmima.csic.es
AF: Institut de Ciencies del Mar, Pg Maritim de la Barceloneta 37-49, Barcelona, 08003 Spain
AU: Cropp, R A
EM: r.cropp@griffith.edu.au
AF: Faculty of Environmental Sciences, Griffith University, Nathan, Qld 4111 Australia
AU: Dachs, J
EM: jdachs@cmima.csic.es
AF: Institut de Ciencies del Mar, Pg Maritim de la Barceloneta 37-49, Barcelona, 08003 Spain
AU: Hirst, T
EM: tony.hirst@griffith.edu.au
AF: CSIRO Division of Atmposheric Research, Private Bag 1,, Mordialloc, Vic 3185 Australia
AB: We have used a marine food-web model, an atmosphere-ocean general circulation model and an empirical dimethylsulfide (DMS) algorithm to simulate the DMS sea-to-air flux under contemporary and enhanced greenhouse conditions. The DMS empirical algorithm utilizes model predictions of surface chlorophyll and the oceanic mixed layer depth. Meteorological forcings were derived from a transient simulation of the CSIRO Mark II general circulation model, using the IPCC/ISP92a radiative forcing scenario to the period of equivalent CO2 tripling (2080). The zonal mean response of DMS production by the marine food web to simulated climate change was computed in ten-degree bands from 70$\deg$N-70$\deg$S. The globally integrated DMS flux perturbation is predicted to be +14 percent. However, the greatest future perturbation to DMS flux will occur at high latitudes in both hemispheres, with little change predicted in the tropics and sub-tropics. The largest change in annual integrated flux (+106 percent) is simulated in the Southern hemisphere between 50$\deg$S-60$\deg$S. At this latitude, the DMS flux perturbation is most influenced by the GCM-simulated changes in the mixed layer depth. Our results suggest an important role of the polar oceans in climate change.
DE: 1600 GLOBAL CHANGE (New category)
DE: 1615 Biogeochemical processes (4805)
SC: Global Climate Change [GC]
MN: 2003 Fall Meeting