Particulate organic matter elemental analysis, mixed layer, during the K-Azis voyage of the Aurora Australis au1603

• Format: Dataset
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: oceans; EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CARBON; ORGANIC CARBON; NITROGEN; CHNS/O ELEMENTAL ANALYZERS > Carbon Hydrogen Nitrogen Elemental Analyzers; IRMS > ISOTOPIC RATIO MASS SPECTROMETER; SHIPS; R/V AA > R/V Aurora Australis; LABORATORY; AMD/AU; CEOS; AMD; GEOGRAPHIC REGION > POLAR; OCEAN > SOUTHERN OCEAN > KERGUELEN PLATEAU; Southern Ocean; Kerguelen; aurora australis
• Online Access: https://researchdata.edu.au/particulate-organic-matter-australis-au1603/2817354

Progress Code: completed Statement: Large chain forming diatoms (Rhizosolenia) were present on occasions and partially excluded by the 210um mesh. One extra station is recorded at CTD0.5 UW which was a surface underway sample within a polynya (no cast was done). Purpose The samples were collected to inform interpretation of co-sampled particulates analysed by flow cam and link to primary productivity and pigment results. A subset of this data has been reported to SOCCOM for stations where a float was launched. Water samples of 1 to 2L from Niskin bottles filled close to the surface, mid mixed layer depth and bottom of the mixed layer were drawn cleanly through a 210um mesh to exclude zooplankton. All samples were filtered as two size fractions, 1.2 to 20um (larger particles excluded by 20um Nitex mesh) and a separate 1.2 to 210um total sample. The filters were 1.2um silver membranes (Sterlitech) 13mm diameter. The samples were preserved by drying at 60C in a dedicated clean oven. Prior to encapsulation, a 5mm diameter subsample was taken for biogenic silica analysis, which is delayed until there has been evaluation of the particle data from the flow cam and UVP. Samples were encapsulated in silver (Sercon sc0037) after acidification and drying. The decarbonated encapsulated POC samples were analysed by elemental analyser at the CSL UTAS by Dr Thomas Rodemann (EA TCD 960C, single point standardisation every 12 samples). EA detection limit 0.001umol POC. POC and PON are presented as molar units. Blanks were process blanks (seawater) and 7% of the average for the combined data n=177. 1sd=0.12uM. The ctd casts were all given the prefix K, so K001, K002 etc. Not all stations were sampled due to budget constraints. Niskin is the Niskin bottle number.