Particle flux data from sediment traps deployed south of -47 (2004-2005)

At the inception of our project, no study had examined particle fluxes in the Subantarctic Zone (SAZ) of the Southern Ocean, despite the fact that the SAZ represents a large portion of the total area of the Southern Ocean, serve as a strong sink for atmospheric (~1G t C yr-1 [Metzl et al., 1999]), and is central to hypotheses linking particle fluxes and climate change [Francois et al., 1997; Kumar et al., 1995; Sigman et al., 1999]. The SAZ serves as an interface between the cold nutrient-rich waters to its south and the nutrient-depleted subtropical gyres to its north. SAZ upper layers are marked by a thick layer of relatively homogenous Subantarctic Mode Water (SAMW), which overlies Antarctic Intermediate Water (AAIW). Both water masses are subducted northward beneath the subtropical gyres. Thus particles leaving the surface in these regions contribute to carbon redistribution via both the fraction that reaches the deep sea by settling and the fraction that is remineralized within SAMW or AAIW and subsequently subducted. The SAZ exhibits surface water carbon dioxide partial pressures well below atmospheric equilibrium, but PFZ waters are closer to atmospheric equilibrium in this sector [Metal et al., 1999; Poppet al., 1999]. The relative physical and biological contributions to these carbon dioxide partial pressure variations are unclear, but it is important to determine them because physical and biological carbon dioxide transfers are expected to show different responses to climate change [ Matear et al., 1999; Sarmiento and LeQuere, 1996]. For these reasons we focused on the SAZ and, for comparative purposes, on the PFZ to its south. We measured particle fluxes using moored sinking particle traps at three sites in the SAZ, in the PFZ, and beneath the Subantarctic Front (SAF), which separates them.

This record describes particle flux data collected between 2004 and 2005. The NetCDF data contains the following variables. Please note not all variables are supplied in all files, specifically there are not uncertainty estimates and no quality control flags for this data.

-----DATA DICTIONARY-----
Name, description, units, standard name
TIME, time, YYYY-MM-DD, time of sample midpoint
TIME_START, time sample open, YYYY-MM-DD, time sample open
NOMINAL_DEPTH, depth, m, nominal depth
LATITUDE, latitude, degrees_north, latitude of anchor
LONGITUDE, longitude, degrees_east, longitude of anchor
pressure_actual, actual, dbar, actual pressure
sample, sample number, 1, sample number
sample_quality_control, quality flag for sample number, unitless, quality flag for sample number
mass_flux, &lt;1mm, mg m-2 d-1, particulate total mass flux
mass_flux_uncertainty, uncertainty for particulate total mass flux, mg m-2 d-1,), uncertainty for particulate total mass flux
mass_flux_quality_control, quality flag for particulate total mass flux, unitless, quality flag for particulate total mass flux
SAL_BRINE, supernatant, 1, sample supernatant practical salinity
SAL_BRINE_uncertainty, uncertainty for sample supernatant practical salinity, 1, uncertainty for sample supernatant practical salinity
SAL_BRINE_quality_control, quality flag for sample supernatant practical salinity, unitless, quality flag for sample supernatant practical salinity
pH_BRINE, supernatant, 1, sample supernatant pH NBS scale
pH_BRINE_uncertainty, uncertainty for sample supernatant pH NBS scale, 1, uncertainty for sample supernatant pH NBS scale
pH_BRINE_quality_control, quality flag for sample supernatant pH NBS scale, unitless, quality flag for sample supernatant pH NBS scale
PC_mass_flux, &lt;1mm, mg m-2 d-1, particulate total carbon mass flux
PC_mass_flux_uncertainty, uncertainty for particulate total carbon mass flux, mg m-2 d-1, uncertainty for particulate total carbon mass flux
PC_mass_flux_quality_control, quality flag for particulate total carbon mass flux,   unitless, quality flag for particulate total carbon mass flux
PN_mass_flux, &lt;1mm, mg m-2 d-1, particulate total nitrogen mass flux
PN_mass_flux_uncertainty, uncertainty for particulate total nitrogen mass flux, mg m-2 d-1, uncertainty for particulate total nitrogen mass flux
PN_mass_flux_quality_control, quality flag for particulate total nitrogen mass flux, unitless, quality flag for particulate total nitrogen mass flux
POC_mass_flux, &lt;1mm, mg m-2 d-1, particulate organic carbon mass flux
POC_mass_flux_uncertainty, uncertainty for particulate organic carbon mass flux, mg m-2 d-1, uncertainty for particulate organic carbon mass flux
POC_mass_flux_quality_control, quality flag for particulate organic carbon mass flux, unitless, quality flag for particulate organic carbon mass flux
PIC_mass_flux, &lt;1mm, mg m-2 d-1, particulate inorganic carbon mass flux
PIC_mass_flux_uncertainty, uncertainty for particulate inorganic carbon mass flux, mg m-2 d-1, uncertainty for particulate inorganic carbon mass flux
PIC_mass_flux_quality_control, quality flag for particulate inorganic carbon mass flux, unitless, quality flag for particulate inorganic carbon mass flux
BSi_mass_flux, &lt;1mm, mg m-2 d-1, particulate biogenic silicon mass flux
BSi_mass_flux_uncertainty, uncertainty for particulate biogenic silicon mass flux, mg m-2 d-1, uncertainty for particulate biogenic silicon mass flux
BSi_mass_flux_quality_control, quality flag for particulate biogenic silicon mass flux, unitless, quality flag for particulate biogenic silicon mass flux
TIME_END, time sample closed, YYYY-MM-DD, time sample closed
Reference, citable reference
DOI, DOI

Tags: Biogeochemical Cycles, Mass_flux, Ocean Chemistry, Oceans, Total particulate carbon flux, biogenic silica flux, particulate inorganic carbon flux, particulate organic carbon flux
Organization: Australian Ocean Data Network