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.