Title NBP0304a_Survery_DOC_Data Author Prof. Dennis A. Hansell Chairman Division of Marine and Atmospheric Chemistry Rosenstiel School of Marine and Atmospheric Science University of Miami 4600 Rickenbacker Causeway Miami, FL 33149 Tel: 1-305-421-4078 FAX 1-305-421-4689 dhansell@rsmas.miami.edu http://www.rsmas.miami.edu/groups/organic-biogeochem/ Dr. N.R. Bates Bermuda Biological Station for Res. Inc. 17 Biological Lane St George's GE01 Bermuda Tel: 1-441 297-1880 (x210) FAX: 1-441 297-8143 nick@bbsr.edu http://www.bbsr.edu/Labs/co2lab/co2main.html Data Contact Prof. Dennis A. Hansell Chairman Division of Marine and Atmospheric Chemistry Rosenstiel School of Marine and Atmospheric Science University of Miami 4600 Rickenbacker Causeway Miami, FL 33149 Tel: 1-305-421-4078 FAX 1-305-421-4689 dhansell@rsmas.miami.edu http://www.rsmas.miami.edu/groups/organic-biogeochem/ Funding Source and Grant Number NSF OPP-0124900 Data Set Overview and Data Collection The dissolved organic carbon (DOC) data contain in this data set was taken during July and August of 2003 aboard the Nathaniel B. Palmer as part of the Arctic Shelf Basin Interactions (SBI) Project. The 2003 Survey Cruise aboard the Palmer was designed to study a broad area, from Bering Strait to out over the deep Arctic Basin of the Chukchi Sea. During this cruise, data for DOC was gathered from the bottom waters of the Chukchi Self and one full transect line from on-shelf to off-shelf east of Point Barrow. The bottom water was taken from the deepest cast depth, usually less than 3 meters above the bottom in water depths of less than 250 meters. The high resolution line was sampled for DOC throughout the water column. Samples were taken using a SeaBird 911+ CTD mounted on a 24- placed rosette frame, with SeaBird pylon, and outfitted with 24 ten liter bottles. To ensure that particulate organic carbon (POC) did not contribute to estimates of DOC in the upper ocean, all samples were filtered through an inline combusted GF/F filter held in acid washed polycarbonate filter holders. The filter cartridge was attached directly to the Niskin bottle with an acid cleaned and MilliQ water rinsed silicone tube. Samples were collected into preconditioned and DOC-free, 60 mL HDPE bottles and frozen in organic solvent free freezers, then shipped in ice to the shore-based laboratories. The filter cartridges were cleaned between uses and newly combusted GF/F filters were loaded prior to sampling each cast. All samples were analyzed using the Shimadzu TOC-V system. Extensive conditioning and standardization procedures were performed prior to analyzing samples each day. Four point standard curves of potassium hydrogen phthalate (KHP) were used to standardize DOC measurements. In addition, seawater DOC reference standards produced by the Hansell CRM program (http://www.rsmas.miami.edu/groups/organic- biogeochem/crm.html) were also analyzed each day. To maintain highest quality data control, samples were systematically checked against low carbon water and deep and surface reference waters every sixth analysis (Hansell and Carlson 1998a). The between-day precision in the DOC measurement was 1-2 M, or a CV of 2-3%. Instrument Description Shimadzu TOC-VCSH. References: http://www1.shimadzu.com/products/lab/toc.html Data Format DOC data is reported in ìmol/l. DATA REMARKS Quality flag 2 are good data. Missing data are -9999.