Oxidizer point sinks

Analysis. To answer the question posed above, we treat the fuel cloud as a pseudo homogeneous or continuum phase (6, 7) with the individually burning particles treated as point sinks of oxidizer. Such an approach is rigorously defensible when the cloud is suflBciently dilute that ... 

The fuel cells and heat sinks occupy more than 80% of the straight line distance between the lower- and the upper-reversal points. Then the gravity forces are particularly effective for the transport of the fuel or the oxidizing agent. 

As pointed out in Section 16.2 (Eq. 16-2), the major source for COj" radicals in advanced oxidation processes, and possibly also in surface water, is reaction of HCO3 and CO3 with hydroxyl radical (HO ). The major sink for COj is regarded to be DOM. The rate constant for reaction of COj" with DOM is in the order of 4x10 L-(mg.oc)-1 s-1 (Larson and Zepp, 1988), which is about 600 times smaller than for the reaction of HO with DOM constituents (see Illustrative Example 16.1). 

Microbial consumption of DMS in the hypolimnion is more difficult to estimate since our laboratory experiments showing degradation have not been rigorous enough to yield degradation rates applicable to natural conditions. However, if we assume that DMS is transported into the hypolimnion by eddy diffusion, with an arbitrary eddy diffusion coefficient of 1 m2/d, the observed concentration gradient across the oxic/anoxic boundary would support a sink for 30 pmol/m2/d DMS produced in the hypolimnion. We therefore hypothesize that anaerobic microbial consumption in the hypolimnion of Salt Pond may be the major sink for DMS produced in the metalimnion. At this point we cannot estimate the potential for DMS oxidation in the epilimnion. 

There was a lot of discussion about the carbon monoxide in the atmosphere. You pointed out that through free radicals carbon monoxide is oxidized to carbon dioxide. Do you believe that this is the real sink for carbon monoxide, in other words, that the scheme you described is really representative for sink for carbon monoxide ... 

Your point is certainly well taken there are many aspects of tropospheric chemistry that are uncertain, and that involving methyl peroxide is without doubt a prime example. From my own estimation of how the methane system works in the atmosphere, I believe that a significant fraction of the methyl peroxide is removed by heterogeneous reactions before it has a chance to react. This terminates the chain making methane oxidation a net sink for OH regardless of the details of the chemistry of methyl peroxide and its daughter molecules. Nevertheless we certainly need to be aware of the many uncertainties in this chemistry. 

In the southern hemisphere, south of 50° latitude, the CO mixing ratio assumes a fairly constant value of about 50ppbv. McConnel et al. (1971) have pointed out that a photostationary state will be set up for CO, if the oxidation of CH4 is the sole source of CO and its reaction with OH radicals is the sole sink. In this case one has... 

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