Particulate organic carbon data in Antarctic waters

The aim of the project was to determine the particulate organic carbon concentration in coastal polynyas and off-shelf sites south of the Polar Front. Data is collected from the CTD deployed at various stations. This record descripbes three datafiles.

(1) POC_data: station, pressure, temperature, conductivity, salinity, PAR, total beam attenuation coefficients (c), attenuation by particles (cp), site, particulate organic carbon concentration (from optical measurements), rho, longitude and latitude.

(2) Ammonium: station, pressure, site, ammonium, latitude, longitude

(3) POC_PON_ratio: site, depth, particulate organic carbon concentration (measured) particulate organic nitrogen concentration (measured), C:N ratio.

Identification info

Date (Creation): 2020-08-11

Date (Publication): 2020-08-17

Citation identifier

10.25959/5f360a58b21a7

Title: Information and documentation - Digital object identifier system

Date (Publication): 2020-08-17

Citation identifier: ISO 26324:2012

Citation identifier: https://doi.org/10.25959/5f360a58b21a7

Principal investigator

Institute for Marine and Antarctic Studies (IMAS) - Ratnarajah, Lavenia

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Moreau, Sebastien

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Janssens, Julie

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Corkill, Matthew

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Duprat, Luis

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Genovese, Cristina

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Collaborator

Centre for Marine Ecosystems Research (CMER) - Puigcorbé, Viena

Edith Cowan University

270 Joondalup Drive

Joondalup

Western Australia

6027

Australia

ORCID ID >

Collaborator

Woods Hole Oceanographic Institution (WHOI) - Roca-Martí, Montserrat

266 Woods Hole Road

Woods Hole

02543-1050

USA

ORCID ID >

Collaborator

Institute for Marine and Antarctic Studies (IMAS) - Lannuzel, Delphine

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Credit: Antarctic Climate and Ecosystems CRC

Credit: Australian Antarctic Division research projects AAS 4131 and 4291

Credit: Institute for Marine and Antarctic Studies, University of Tasmania

Credit: L. Ratnarajah also received support from BYONIC (ERC award number 724289 awarded to Alessandro Tagliabue)

Credit: S. Moreau and C. Genovese were supported by the Australian Research Council’s Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001)

Credit: V. Puigcorbé was supported by Edith Cowan University through an Early Career Researcher Grant (G1003456) and an ECU-Collaboration Enhancement Scheme grant

Status: Completed

Point of contact

Institute for Marine and Antarctic Studies (IMAS) - Ratnarajah, Lavenia

IMAS - Hobart

Private Bag 129

Hobart

Tasmania

7001

Australia

ORCID ID >

Topic category

Oceans

Extent

Temporal extent

Time period: 2016-12-08 2017-01-21

Maintenance and update frequency: Not planned

NASA/GCMD Keywords, Version 8.5

Australian and New Zealand Standard Research Classification (ANZSRC): Fields of Research

AODN Platform Vocabulary

research vessel

AODN Discovery Parameter Vocabulary

Keywords (Theme)

Photosynthetically active radiation (PAR)

AODN Instrument Vocabulary

Keywords (Instrument)

Niskin bottle deployed from CTD

Resource constraints

Classification: Unclassified

Resource constraints

Use limitation: The data described in this record are the intellectual property of the University of Tasmania through the Institute for Marine and Antarctic Studies.

Resource constraints

Linkage: http://i.creativecommons.org/l/by/4.0/88x31.png
License Graphic

Title: Creative Commons Attribution 4.0 International License

Website: http://creativecommons.org/licenses/by/4.0/
License Text

Other constraints: Cite data as: Ratnarajah, L. & Lannuzel, D. (2020), Particulate organic carbon data in Antarctic waters. Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS). https://doi.org/10.25959/5f360a58b21a7

Language: English

Character encoding: UTF8

Content Information

Content type: Physical measurement

Identifier

Code: Temperature of the water body

Identifier

Code: Electrical conductivity of the water body

Identifier: http://vocab.nerc.ac.uk/collection/P06/current/UECA

Name: Siemens per metre

Identifier

Code: Practical salinity of the water body

Identifier: http://vocab.aodn.org.au/def/unitsofmeasure/entity/481

Name: Practical Salinity Unit

Name: Photosynthetically active radiation (PAR)

Identifier: http://vocab.aodn.org.au/def/unitsofmeasure/entity/585

Name: Micromoles per second per square metre

Identifier

Code: Pressure (measured variable) in the water body exerted by overlying sea water only

Identifier: http://vocab.nerc.ac.uk/collection/P06/current/UPDB

Name: Decibars

Identifier

Code: Particulate Organic Carbon (POC)

Name: Moles per litre

Identifier

Code: Particulate Organic Nitrogen (PON)

Name: Moles per litre

Identifier

Code: C:N ratio

Name: ratio

Identifier

Code: Concentration of ammonium {NH4} per unit volume of the water body

Identifier: http://vocab.nerc.ac.uk/collection/P06/current/UPOX

Name: Micromoles per litre

Distribution Information

Distribution format

OnLine resource: DATA ACCESS - POC data (optical sensor), and PON/POC data from CTD bottles [file browse]

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_POC
MAP - CTD sampling locations (POC from optical sensor)

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_POC_PON
MAP - CTD sampling locations with Niskin collected for POC and PON sampling

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_Ammonium
MAP - CTD sampling locations with Niskin collected for Ammonium sampling

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_POC
OCG WFS service for data (POC from optical sensor)

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_POC_PON
OGC WFS service for data (POC:PON ratios from Niskin water sample)

OnLine resource: imas:ACE_Ratnarajah_AntarcticCTD_Ammonium
OCG WFS service for data (Ammonium from Niskin water sample)

OnLine resource: View and download this data through the interactive IMAS Data Portal.

Resource lineage

Statement: A total of 70 CTD (conductivity-temperature-depth, SeaBird 704, SeaBird Inc., Bellevue, USA) casts were undertaken within the Dalton (n = 20), Mertz (n = 24) and Ninnis (n = 14) polynyas, and north of the shelf moving away from the coastal polynyas (n = 12). Seawater samples were collected from Niskin bottles triggered at various depths during the CTD cast. Between 4 and 6 depths (10 – 200 m) were sampled for POC and PON based on the CTD Photosynthetic Available Radiation (PAR) and Chl-a profiles (Moreau et al. 2019). Seawater samples were filtered (475 – 1055 mL depending on organic matter content) onto pre-combusted (450°C for 12 h), 25 mm, quartz fiber filters (Advantec). All glassware in contact with POC samples were also pre-combusted prior to the voyage and subsequently rinsed with 2% v/v hydrochloric acid and ultra-high purity water between samples. Filters were then removed and placed into individual, sterile filter holders and wrapped in pre-combusted aluminium foil to limit light exposure. Filters were stored at −20°C until analysis (~6 months). Nine unused, pre-combusted filters were analyzed as ‘filter blanks’ to quantify background concentration of POC and PON on the filters. Particulate organic carbon and nitrogen were determined using standard carbon-hydrogen-nitrogen combustion methods (Knap et al. 1994). Filters were removed from storage, punched to 15.9 mm, and dried in an oven at 60°C overnight in muffled glass trays. 80 μL of 10% v/v hydrochloric acid was then added to each filter to remove any inorganic carbon. The acid-treated filters were subsequently dried in a desiccator overnight, folded and enclosed into 8x5 mm silver capsules (Elemental Microanalysis, UK) and analyzed at the Central Science Laboratory, University of Tasmania, using a Thermo Finnigan EA 1112 Series Flash Elemental Analyzer (estimated precision ~ 1%). The final sample POC and PON concentrations were calculated by subtracting the average carbon and nitrogen content measured in the filter blanks (2 ± 1 µg for carbon and 0.3 ± 0.1 µg for nitrogen), multiplying by the filter to punch area ratio and dividing the values by the volumes filtered. Particulate organic carbon measurements were not corrected for possible dissolved organic carbon adsorption on the GF/F filter. We obtained estimates of POC distribution along the water column by relating the discrete POC concentration to an in situ optical instrument - transmissometer at 660 nm (Wetlabs C-star serial no. 1421DR 25 cm pathlength). The up-cast transmissometer profile of the water column was used as it paired with the firing of the Niskin bottles for subsequent POC analysis in water. Baseline data were vertically averaged in 2dbar (~2 meter) bins. Factory calibration details are presented in Rosenberg and Rintoul (2017). The optical sensor output was delivered in percent units. The percent transmission (Tr) of light was then converted to total beam attenuation coefficients, c, using: c = -(1 / r) * ln (Tr / 100) where c = beam attenuation coefficient (m-1), r = beam path length (m), and Tr = beam transmission (%) (Gardner 1995). The beam attenuation coefficient (c) represents the sum of attenuation due to particles (cp), water (csw) and colored dissolved organic matter (CDOM). Scattering and absorption by CDOM is considered negligible in most open ocean waters, so attenuation by particles (cp) equals the total attenuation measured (c) minus the attenuation by water (csw): cp = c - csw where csw was derived from measurements of c at 2000 m depth at the off shelf sites, where particle concentrations can be assumed to be negligible. The POC:cp relationship was assessed based on sites where POC and cp were simultaneously collected. Particulate attenuation, cp, of the profiling transmissometer were linearly correlated with discrete POC concentration (the coefficient of determination, R2 = 0.83). There was no evidence that the intercept of the relationship between the in situ POC concentration and particle attenuation varied by site (p = 0.1), which allowed for the POC concentrations to be pooled across all CTDs for each polynya, and the off-shelf stations. cp was transformed to POC concentration (mg m-3) via a single linear equation: POC = 26.8 + 370.6cp Data file contents are as follows: (1) POC_data (from optical sensor on Seabird CTD): station, pressure, temperature, conductivity, salinity, PAR, total beam attenuation coefficients (c), attenuation by particles (cp), site, particulate organic carbon concentration (from optical measurements), rho, longitude and latitude. (2) Ammonium (collected from individual CTD Niskin bottles): station, pressure, site, ammonium, latitude, longitude (3) POC_PON_ratio (collected from individual CTD Niskin bottles): site, depth, particulate organic carbon concentration (measured) particulate organic nitrogen concentration (measured), C:N ratio.

Hierarchy level: Dataset

Hierarchy level: Dataset

Platform

Identifier

Code: research vessel

Instrument

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Code: CTD

Hierarchy level: Dataset

Instrument

Identifier

Code: CTD

Hierarchy level: Dataset

Instrument

Identifier: Niskin bottle deployed from CTD

Metadata

Metadata identifier: urn:uuid/02364e10-ebc0-463a-b690-2c4ed643733c

Language: English

Character encoding: UTF8

Publisher

Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS) - IMAS Data Manager

Type of resource

Resource scope: Dataset

Metadata linkage: https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/02364e10-ebc0-463a-b690-2c4ed643733c
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Date info (Creation): 2021-03-29T21:59:12

Date info (Revision): 2024-10-05T21:23:40

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Title: ISO 19115-3:2018

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