Description: This data set includes the concentration of surface water volatile organic compounds and carbon monoxide, biomass concentrations and temperature from the ferry box system of RV POLARSTERN on the cruise track from Bremerhaven to the ice covered region north of Svalbard during RV POLARSTERN cruise PS92. Temperature and salinity were used to classify the sampled water masses based on the criteria applied in Tran et al., 2013.

Description: Isoprene concentrations in the surface Arctic waters, measured during the TRANSSIZ cruise from May 20th to May 27th, 2015, on board the R/V Polarstern. Measurements were made on-line with water extracted from the "ship's membrane pump" (~6m under the surface).

Description: Isoprene concentrations in the surface South Atlantic waters, measured during the OOMPH (Leg 2) cruise in March 2007 on board the R/V Marion Dufresne. Measurements were made on-line with water extracted from the "ship's membrane pump" (~8m under the surface).

Description: In support of the first Tropospheric Ozone Assessment Report (TOAR) a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone metrics products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues, which are part of this special feature. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allow for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone. Cooperation among many data centers and individual researchers worldwide made it possible to build the world's largest collection of in-situ hourly surface ozone data covering the period from 1970 to 2015. Considerable effort was made to harmonize and synthesize data formats and metadata information from various networks and individual data submissions. Extensive quality control was applied to identify questionable and erroneous data, including changes in apparent instrument offsets or calibrations. Such data were excluded from TOAR data products. Limitations of a posteriori data quality assurance are discussed. As a result of the work presented here, global coverage of surface ozone data has been significantly extended. Yet, large gaps remain in the surface observation network both in terms of regions without monitoring, and in terms of regions that have monitoring programs but no public access to the data archive. Therefore future improvements to the database will require not only improved data harmonization, but also expanded data sharing and increased monitoring in data-sparse regions.

Description: This data set contains the concentrations of chlorohyll a (chla) and the phytoplankton fuctional types from the CTD stations during PS 92, which were calculated from marker pigment ratios using the CHEMTAX program (Mackey et al, 1996).Pigment ratios were constrained as suggested by Higgins et al. (2011) based on microscopic examination of representative samples during the cruise, and the input matrix published by Fragoso et al. (2016) was applied. The resulting phytoplankotn group composition is represented in chl a concentrations. From the same bottles various trace gases were measured as carbon monoxide (CO) and the Volatile Organic Compounds (VOCs) as Dimethyl sulphide (DMS), methanethiol (MeSH) and isoprene.

Description: 〈jats:p〉Abstract. Dimethyl sulfide (DMS) plays an important role in the atmosphere by influencing the formation of aerosols and cloud condensation nuclei. In contrast, the role of methanethiol (MeSH) for the budget and flux of reduced sulfur remains poorly understood. In the present study, we quantified DMS and MeSH together with the trace gases carbon monoxide (CO), isoprene, acetone, acetaldehyde and acetonitrile in North Atlantic and Arctic Ocean surface waters, covering a transect from 57.2 to 80.9∘ N in high spatial resolution in May–June 2015. Whereas isoprene, acetone, acetaldehyde and acetonitrile concentrations decreased northwards, CO, DMS and MeSH retained substantial concentrations at high latitudes, indicating specific sources in polar waters. DMS was the only compound with a higher average concentration in polar (31.2 ± 9.3 nM) than in Atlantic waters (13.5 ± 2 nM), presumably due to DMS originating from sea ice. At eight sea-ice stations north of 80∘ N, in the diatom-dominated marginal ice zone, DMS and chlorophyll a markedly correlated (R2 = 0.93) between 0–50 m depth. In contrast to previous studies, MeSH and DMS did not co-vary, indicating decoupled processes of production and conversion. The contribution of MeSH to the sulfur budget (represented by DMS + MeSH) was on average 20 % (and up to 50 %) higher than previously observed in the Atlantic and Pacific oceans, suggesting MeSH as an important source of sulfur possibly emitted to the atmosphere. The potential importance of MeSH was underlined by several correlations with bacterial taxa, including typical phytoplankton associates from the Rhodobacteraceae and Flavobacteriaceae families. Furthermore, the correlation of isoprene and chlorophyll a with Alcanivorax indicated a specific relationship with isoprene-producing phytoplankton. Overall, the demonstrated latitudinal and vertical patterns contribute to understanding how concentrations of central marine trace gases are linked with chemical and biological dynamics across oceanic waters. 〈/jats:p〉

Description: Environmental context. Carbon monoxide (CO) is a key component for atmospheric chemistry and its production in the ocean, although minor at the global scale, could play a significant role in the remote marine atmosphere. Up to now, CO production in the ocean was considered to mainly originate from the photo-production of dissolved organic matter (mainly under UV radiation). In this paper, we show evidence for direct production of CO by phytoplankton and we suggest it as a significant mechanism for CO production in the ocean. Abstract. In order to investigate carbon monoxide (CO) emissions by phytoplankton organisms, a series of laboratory experiments was conducted in Kiel (Germany). Nine monocultures, including diatoms, coccolithophorids, chlorophytes and cyanobacteria have been characterised. This was done by following the CO variations from monoculture aliquots exposed to photosynthetically active radiation during one or two complete diurnal cycles. All the studied cultures have shown significant CO production when illuminated. Emission rates have been estimated to range from 1.4 × 10–5 to 8.7 × 10–4 μg of CO μg chlorophyll–1 h–1 depending on the species. When considering the magnitude of the emission rates from the largest CO emitters (cyanobacteria and diatoms), this biotic source could represent up to 20% of the CO produced in oceanic waters. As global models currently mainly consider CO production from the photo-degradation of dissolved organic matter, this study suggests that biotic CO production should also be taken into account. Whether this biological production might also contribute to some degree to the previous observed non-zero CO production below the euphotic zone (dark CO production) cannot be deduced here and needs to be further investigated.