Short-lived trace gases (DMS, isoprene, acetaldehyde and acetone) in the surface waters of the western Pacific and eastern Atlantic Oceans

• Main Author: Zindler, Cathleen
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: Pacific; Ocean acidification
• Online Access: https://oceanrep.geomar.de/id/eprint/22382/; https://oceanrep.geomar.de/id/eprint/22382/1/doktorarbeit_Zindler.pdf

The exchange of trace gases between the surface ocean and the lower atmosphere has received increasing attention during the last years especially in view of ongoing global environmental changes such as eutrophication, warming of the ocean, ocean acidification etc. The ocean has been identified as a huge reservoir of various climate relevant trace gases. However, the distributions and the pathways of the trace gases such as isoprene, acetone and acetaldehyde, in the surface seawater is poorly understood. Even consensus regarding the intensively studied dimethylsulphide (DMS) pathways continues to elude researchers to date. This thesis compiles different studies which contribute new insight into the fates of a group of short-lived, climate-relevant traces gases including DMS, isoprene, acetaldehyde and acetone in the surface layers of the Pacific and Atlantic Oceans: • The distribution of and the interactions between DMS, dimethylsulphoniopropionate (DMSP) and dimethylsulphoxide (DMSO) in surface seawater were examined in conjunction with the phytoplankton composition and methane along a northsouth transit in the western Pacific Ocean on board the R/V Sonne (TransBrom) from Tomakomai (Japan) to Townsville (Australia) from 9th to 24th 2009. A close link between DMSP and DMSO was found based on correlations between the two compounds and similar phytoplankton pigments, which were identified as presumably sources of both DMSP and DMSO. The detected DMSPp:DMSOp seemed to be typical for an oligotrophic tropical ocean and might indicate stress conditions for phytoplankton due to intensive solar radiation and nutrient limitation which in turn may have led to an accumulation of DMSO in the surface water of the western Pacific Ocean. It seems that DMSP and DMSO were more closely related to each other than to DMS. It was evident that different factors influence the DMS distribution, as underlined by the failure to identify phytoplankton groups as sources for DMS. Moreover, DMSP and DMSO were identified as possible substrates ...