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  • Coccolithophore fluxes were investigated over a one-year period (2001-02) at the southern Antarctic Zone in the Australian Sector of the Southern Ocean at the site of the Southern Ocean Iron Release Experiment (SOIREE) near 61°S, 140°E. Two vertically moored sediment traps were deployed at 2000 and 3700 m below sea-level during a period of 10 months. In these data sets we present the results on the temporal and vertical variability of total coccolith flux, species composition and seasonal changes in coccolith weights of E. huxleyi populations estimated using circularly polarised micrographs analysed with C-Calcita software. A description of the field experiment, diatom and biogeochemical fluxes can be found in Rigual-Hernández et al. (2015), while a detailed description of sample processing and counting of coccolithophores can be found in Rigual-Hernández et al. (2018). Moreover, an explanation of the estimation of Emiliania huxleyi coccoliths using C-Calcita software can be also found in Rigual-Hernandez et al. (2018). Coccolithophore assemblages captured by the traps were nearly monospecific for Emiliania huxleyi morphotype B/C. Coccolith fluxes showed strong seasonal cycle at both sediment trap depths. The maximum coccolith export occurred during summer and was divided into two peaks in early January (2.2 x 109 coccoliths m-2 d-1 at 2000 m) and in mid-February (9.8 x 108 coccoliths m-2 d-1). Coccolith flux was very low in winter (down to ~7 x 107 coccoliths m-2 d-1). Coccolith fluxes in the deeper trap (3700 m) followed a similar pattern to that in the 2000 m trap with a delay of about one sampling interval. Coccoliths intercepted by the traps exhibited a weight and length reduction during summer. The annual coccolith weight at both sediment traps was 2.11 plus or minus 0.96 and 2.13 plus or minus 0.91 pg at 2000 m and 3700 m, respectively. Our coccolith mass estimation was consistent with previous reports for morphotype B/C in other regions of the Southern Ocean. Data available: two excel files containing sampling dates and depths, raw counts, relative abundance and fluxes (coccoliths m-2 d-1) of the coccolithophore species, and morphometric measurements of Emiliania huxleyi coccoliths made with C-Calcita software. Each file contains four spreadsheets: raw coccolith counts, relative abundance of coccolithophore species and coccolith flux of each coccolithophore species identified and E. huxleyi morphometrics. Detailed information of the column headings is provided below. Cup – Cup (=sample) number Depth – vertical location of the sediment trap in meters below the surface Mid-point date - Mid date of the sampling interval Length (days) – number of days the cup was open

  • Coccolithophore fluxes were investigated over a one-year period at two sites of the Subantarctic Zone in the Australian and New Zealand Sectors of the Southern Ocean. The samples from the Australian SAZ were retrieved at the SOTS observatory, which lies in the SAZ (near 47°S, 142°E), approximately 500 km south west of Tasmania. SOTS was instrumented with three moored platforms: (i) a surface tower buoy that performs meteorological measurements (the Southern Ocean Flux Station - SOFS); (ii) a surface mixed layer mooring equipped with an automated water sampler) and nutrient, carbon and biological measurement sensors (the Pulse mooring); and (iii) a bottom-tethered deep sediment trap mooring that collects sinking particle fluxes for diverse biogeochemical studies (the SAZ mooring). The samples from New Zealand came from the deep-ocean SAM mooring deployed in Subantarctic waters south east of New Zealand (46°40’S, 178’ 30°E), and was equipped with sediment traps and a suite of sensors. Here, we report the coccolith sinking assemblages captured by sediment traps at ~1000, 2000 and 3800 m depth for a year from August 2011 until July 2012 at the SOTS observatory and a sediment trap at ~1500 m depth for a year from November 2009 until October 2010 at the SAM site. A description of the field experiment, sample treatment, determination of total CaCO3 content, and estimation of coccolith and coccosphere fluxes can be found in Rigual-Hernández et al. (2020a) and Rigual-Hernández et al. (2020b). Data available: two excel files (one for each station) containing sampling dates and depths, relative abundance of coccolith sinking assemblages, and coccolith, coccosphere and total CaCO3 fluxes. Detailed information of the column headings is provided below. Cup – Cup (=sample) number Depth – vertical location of the sediment trap in meters below the surface Mid-point date - Mid date of the sampling interval Duration (days) – number of days the cup was open

  • Please also see the child records of this project for access to data. Attached to this record are the originally supplied datasets for 1997-1998, and also summary files and mooring diagrams supplied in 2012. Taken from the 2008-2009 Progress Report: Progress against objectives: The key to advancing the objective of understanding ocean processes controlling uptake of atmospheric CO2 is the ability to deploy moored autonomous samplers and sensors in Southern Ocean surface waters capable of quantifying seasonal cycles in biological and biogeochemical processes. Our effort in the last 12 months has focused on development of a robust mooring platform to carry these devices. We deployed two different engineering test designs, known as Pulse 5 Heavy and Pulse 5 Light. Both designs survived 6 months in the sea, including wave heights up to 12 meters, while transmitting mooring tensions, mooring accelerations, and GPS positions live to the internet (www.imos.org.au). Following this success we are preparing to deploy the next version of Pulse with scientific instruments to measure temperature, salinity, oxygen, and phytoplankton fluorescence. In addition we deployed a deep ocean mooring with time-series sediment traps to quantify sinking particle fluxes, and in-situ settling columns to determine particle sinking rates. Taken from the 2009/2010 Progress Report: Progress against objectives: Two voyages were awarded by the Australian Marine National Facility to use RV Southern Surveyor to service these Southern Ocean Time Series (SOTS) moorings in the 2009/10 season, and for this reason the shiptime awarded to this project by AAS was not needed and was relinquished. This arrangement will continue in 2010/11 for which the MNF has again awarded two voyages in September 2010 and April 2011. The fieldwork in 2009/10 was very successful: i) the SAZ deep sediment trap mooring was recovered in September 2009 and redeployed for recovery in September 2010. ii) the PULSE biogeochemistry mooring was deployed in September 2009 and functioned beautifully prior to recovery in March 2010 for servicing. It will be redeployed in September 2010. iii) the SOFS Southern Ocean Flux Station mooring was completed and deployed in March 2010 for recovery in April 2011, and redeployment in September 2011.

  • From 1991 to 2000 14 voyages have been completed in the Southern Ocean. Measurements of DMS (Dimethylsulfide) and DMSP (Dimethylsulfoniopropionate) have been carried out on surface and subsurface waters together with physical and biological measurements, with a view to understanding the main processes that affect DMS in the Southern Ocean. The first flux measurements have been carried out for DMS (see Curran and Jones 2000) in the last 3 years a concerted study has been carried out in the seasonal ice zone this study aims to identify the major phytoplankton assemblages responsible for DMS and DMSP production in the sea ice zone. It is thought that the sea ice zone also contributes to DMS in the atmosphere. This is being quantified. The fields in this dataset are: Site Date Time (local) Latitude Longitude Snow Cover (metres) Core Length (metres) DMSPt (nano Mols) Chlorophyl a (micrograms per litre) Sea Ice depth (metres) Pigments Fucoxanthin (micrograms per litre) Peridinin (micrograms per litre) 19' hexanoyloxyfucoxanthin (micrograms per litre) Salinity (ppt) Nitrate (micro Mols) Nitrite (micro Mols) Silicate (micro Mols) Phosphate (micro Mols)