California Current Ecosystem LTER

Total Dissolved Organic Carbon (CalCOFI Cruise)

Title
Total dissolved organic carbon measurements at standard depths in the water column from nine CalCOFI cruises, 2008-2015.

Abstract
Water column bottle samples at multiple depths are taken during CalCOFI cruises (since 2006, ongoing) at various CTD stations, and measurements of total organic carbon (TOC) are performed onshore in the lab. TOC includes both dissolved and particulate organic carbon (DOC and POC, respectively). In open ocean waters, POC is subtracted from TOC, and likely provides an accurate estimate of DOC because particles are typically small and homogeneously distributed in the sample. In coastal waters, and at stations where relatively high chlorophyll concentrations are present, the TOC measurement is not easily converted to DOC by subtracting POC values. Experience has shown that particles in these regions are large and inhomogeneously distributed. Therefore, samples collected in the CCE are reported as TOC, expressed as micromoles of carbon per liter of sea water.

Keywords
marine, measurements, carbon, organic matter, organic carbon

LTER Data System Record
http://dx.doi.org/10.6073/pasta/2e522c2580bb25185790bba89772aaaf
Projects
California Current Ecosystem LTER
CalCOFI - Scripps Institution of Oceanography

Creators
Aluwihare, Lihini (laluwihare@ucsd.edu)

Contact
CCE LTER Information Manager (ccelter.im@gmail.com)

Other Personnel
Porrachia, Magali technician
Stephens, Brandon graduate student

Data

table TOC
Main data table for dataset
Rows: 6748
Columns: 12
View / Download

Methods


Total Organic Carbon
An acidified seawater sample (< pH 3) is sparged with CO2 free air to remove inorganic carbon. The water is then injected onto a combustion column packed with platinum-coated alumina beads held at 680°C. Non-purgeable organic carbon (NPOC) compounds are combusted and converted to CO2 , which is detected by a nondispersive infrared detector (NDIR).

Calibration and Reference Standards
5-8 point calibration curve ranging in concentration between 10 μM and 120 μM C of potassium hydrogen phthalate in Milli Q water.