Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Surface particulate carbon concentration, nitrogen concentration, and bulk isotope composition (C and N) from underway clean water intake during June 2019 at station ALOHA during cruise KM1910.

Sampling and analytical procedures:

Suspended particulates were collected while underway using the ship's clean surface water intake ( ~0 to 5 m ocean depth) in the hydro lab sink aboard RV Kilo Moana. Water was passed through three separate filter holders containing 1) an acid-washed 53um mesh screen pre-filter followed by 2), a combusted (4.5hrs 450 degrees C) 142mm GF/F (Whatman nominal pore size 0.7um) and finally followed by 3), a combusted 142mm GF75 (Advantec nominal pore size 0.3um). Samples were folded (active side in) and stored in clean (combusted) foil at -20 degrees C until subsampled with metal cork borer (subsamples were not acidified so PC and d13C represents total C). Subsamples were oven-dried overnight at 55-60 degrees C then packed in 9x11 tin capsules for analysis on EA IRMS. Six blank (dry) filters were analyzed for background C and N and subtracted from measured PC and PN sample values.

Instruments:

EA-IRMS: a Vario ISOTOPE select (Elementar Isoprime) was used to quantify total C, N, and d13C and d15N. Samples are combusted/reduced at high temperature to create gases (CO2 and N2); column chromatography separates the gases; a thermal conductivity detector determines the carbon and nitrogen concentrations, followed by an isotope ratio mass spectrometer for bulk isotope composition. Measurements were calibrated with an in-house aminocaproic acid standard (ACROS) and four USGS standards (#41, #41a, #65, #25).  Analytical uncertainty (determined from standards with similar isotope values) was 0.2‰ for delta-15N and 0.1‰ for delta-13C. 

Known problems:

Lat and Lon was not recorded at end of sample starting at 11:51 and ending at 15:30 on 190617

BCO-DMO Processing:
- converted date_HST to YYYY-MM-DD format;
- created UTC date/time field in ISO8601 format.

NSF Award Abstract:

Intellectual Merit
The PIs request funds to provide training in leading and organizing research cruises to early career researchers in the areas of Biological and Chemical Oceanography. Participants in this training program would be introduced to pre-cruise planning and logistics, receive training in commonly used oceanographic sampling equipment, and conduct shipboard measurements during a 10-day oceanographic cruise to the North Pacific Subtropical Gyre (NPSG). The goal of this training program is to prepare early career scientists for leading and participating in interdisciplinary oceanographic research at sea.

Broader Impacts
The proposed program addresses the broader impacts criteria successfully. The research cruise and follow-up reports and publications focus on interdisciplinary questions important for advancing the field. Given the rapid changes that oceanic systems are undergoing, it is important to have a cadre of junior scientists who are adept at managing interdisciplinary collaborations and conducting research at sea. The PIs are considering ways to connect with diverse audiences in recruiting participants. The impact on early career oceanographers will be very strong. This will create an experience that will be a major impact on the careers of the trainees, especially if they stay in the oceanography field.