Winter season Southern Ocean distributions of climate-relevant trace gases

[摘要] Climate-relevant trace gas air–sea exchange exerts animportant control on air quality and climate, especially in remote regionsof the planet such as the Southern Ocean. It is clear that polar regionsexhibit seasonal trends in productivity and biogeochemical cycling, butalmost all of the measurements there are skewed to summer months. If we wantto understand how the Southern Ocean affects the balance of climate throughtrace gas air–sea exchange, it is essential to expand our measurementdatabase over greater temporal and spatial scales, including all seasons.Therefore, in this study, we report measured concentrations ofdimethylsulfide (DMS, as well as related sulfur compounds) and isoprene in theAtlantic sector of the Southern Ocean during the winter to understand thespatial and temporal distribution in comparison to current knowledge andclimatological calculations for the Southern Ocean. The observations ofisoprene are the first in the winter season in the Southern Ocean. We foundthat the concentrations of DMS from the surface seawater and air in theinvestigated area were 1.03  ±  0.98 nmol −1 and 28.80  ±   12.49 pptv, respectively. The concentrations of isoprene in surface seawater were14.46  ±  12.23 pmol −1 . DMS and isoprene fluxes were 4.04  ±  4.12  µ mol m −2  d −1 and 80.55  ±  78.57 nmol m −2  d −1 , respectively. These results are generally lower than the valuespresented or calculated in currently used climatologies and models. Moredata are urgently needed to better interpolate climatological values andvalidate process-oriented models, as well as to explore how finermeasurement resolution, both spatially and temporally, can influence air–seaflux calculations.

[学科分类] 大气科学