Title: Discoverer Dissolved CO

Contact:

   Ollie Zafiriou
   Woods Hole Oceanographic Institution (WHOI)
   Woods Hole, MA 02543-1050
   U.S.A.
   E-Mail Address: ozafiriou@cliff.whoi.edu


Data Set Description:

Dissolved Carbon Monoxide (Biological) Loss Rates Data

NOAA Ship Discoverer
Dissolved Carbon Monoxide data
Reduced and compiled by WHOI
Version 1:  23 March 1998
Contact:  Ollie Zafiriou

     Microbial CO oxidation rates were measured in
time-course incubations in very dim room light within 1
degree C of in-situ temperatures.  Aqueous [CO] was measured
by headspace-equilibration and analysis of the gas phase
using a Trace Analytical RGA-3 GC/HgO detector system.
Samples' [CO] data vs. time were fitted to exponential
decay kinetics to produce first-order decay rate constants.
The initial "T0" points are approximately 1.5 +/- 0.5 hours
after CTD arrival on deck.  Regression r^2 values of 1.000
generally indicate values derived from only two points (ie.
data were lost).  Duplicate 100-ml all-glass syringes with
3-way Nylon valves were filled per sample, permitting
analysis of 3 aliquots per syringe over time (~18- 24
hours).  Niskin-bottle samples were obtained daily at
mid-morning CTD casts from 5m depth and two or more other
mid- and deeper- ML depths.  Nominal depths are indicated;
CTD data show actual depths were usually within one meter of
the indicated value.  (The mid- and deeper ML depths were
chosen by eye on the downcast; often later examination of
the data showed they were deeper than the actual ML,
narrowly defined.)  Samples were also drawn from the ship's
clean underway surface (~4m) pumping system at nearly the
same time as the CTD cast bottles were being triggered, and
are referenced to the associated cast number.

     It should be noted that the surface system samples'
initial concentrations generally agreed very poorly with the
5m bottle concentration (reason unknown).  Rates from the
pumping system samples resembled those from 5m bottles on
average, but did not agree nearly as well with the
concurrent 5m bottle samples as duplicates agreed,
suggesting significant sample-to-sample variability, or some
effect(s) of the sampling procedure.

Note:  negative CO decay rate corresponds to CO loss


Format: space-delimited ASCII; data sorted by date and nominal depth

Date (YYYY/MM/DD) (UTC)
Time (HH:MM:SS) (UTC)
CTD_DI (cast#)
Syringe#
inc#
Julian Decimal Day (UTC)
Latitude (deg N)
Longitude (deg E)
nomdepth (m)
DissCO (nMolar)
decay_rate (CO decay rate/hr)
r^2 (decay rate regression)

Data for clean surface seawater pumping system only; sorted by Latitude
(depth for all samples was about 4m) same as above but excluding the
nomdepth field.


File Name Conventions:
   zafirio1.dat - primary data file
   zafirio2.dat - data for clean surface seawater pumping system only


References: None.