Dataset: th234_pump
Deployment: TT043

Samples were collected using either:a) in-situ battery powered pump, the "Slurper", or b) ship’s seawater line.  In general, 200 liter samples were passed sequentially through a Nitex screen (53 micron), Quartz filter (1 micron) and two thorium adsorber cartridges.

Samples were collected on legs 1 (Jan.), 2 (March), 4 (July) and 5 (August) with a few additional samples in early July (SeaSoar cruise).  On each cruise: Surface samples were collected at every station (n>30); 0-100 meter composite samples were colelcted at every intermediate nd long station (n>14); and discrete depth samples were collected at every long station (n>5).

At sea analyses included: a) direct beta counting for all filters and some adsorbers samples counted 4-5 times to ensure accuracy and precision and b) direct gamma counting for adsorbers.

Post-cruise analyses included: a) CHN on all filters for POC content and b)  radiochemical purification and samples plus standards counted on calibrated detectors.

Reference:
Buesseler, Ken, Lary Ball, John Andrews, Claudia Benitez-Nelson, Rebecca Belastock, Fei Chai and Yi Chao (1998). Upper ocean export of particulate organic carbon in the Arabian Sea derived from thorium-234 in Arabian Sea Expedition, Part I. Deep-Sea Research, 45(10-11): 2461-2487, U.S. JGOFS Contribution No. 411.

   PI:              Ken Buesseler
  of:              Woods Hole Oceanographic Institution
  dataset:         Th-234 in particulate and dissolved phases; POC/PON
  dates:           January 08, 1995 to January 31, 1995
  location:        N: 22.4831  S: 9.9993  W: 57.3137  E: 68.7507
  project/cruise:  Arabian Sea/TN043 - Process Cruise 1 (Late NE Monsoon)
  ship:            Thomas Thompson
 

Buesseler notes:

            Where greater than 53 micron data is missing,
  	    1 to 53 micron is actually greater than 1 micron
            size fraction.

            The "Slurper" is an in-situ pump capable of sampling
            discrete depths or integrating over a depth range.

            On TTN043 and TTN045, surface samples were collected 
            using the ship's seawater line.  On TTN049, surface
            samples were collected using both the ship's line and
            the Slurper.  On TTN050, all samples were collected with
            the Slurper, including surface samples.