The Effects on the Atmosphere of a Major Nuclear Exchange (1985) / Chapter Skim
Currently Skimming:
6 Chemistry
6 Chemistry
Pages 107-126
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 107... ...
GASEOUS EMISSIONS FROM NUCLEAR FIREBALLS AND NUCLEAR WAR FIRES Nitric Oxide Nuclear explosions produce nitric oxide (NO) by heating air to very high temperatures both in the interior of the fireball and in the accompanying shock wave.
|
From page 108... ...
It should be emphasized that the emission factor for nitrogen oxides produced in nuclear explosions is based wholly on theoretical considerations and that there has not yet been any attempt at experimental verification of the amounts produced. Sedlacek et al.
|
From page 109... ...
See Chapter 3 for details. bBaseline scenario plus 100 weapons of 20-Mt yield.
|
From page 110... ...
As a result, the methane * Unless otherwise noted, all emission factors quoted refer to the mass of a particular chemical species produced per mass of fuel consumed.
|
From page 111... ...
Oxides of Nitrogen Data for nitrogen oxide emissions in forest and urban fires are still limited. The flame temperatures are generally not high enough in isolated fires to produce nitric oxide directly from air.
|
From page 112... ...
Recently, estimates have been made of ozone reductions from NOX injections for various nuclear war (Chang and Wuebbles, 1982; Crutzen and Birks, 1982~. all of these studies and their respective scenarios Table 6.1.
|
From page 113... ...
For this reason alone, it is expected that a large perturbation in the stratospheric burden of NOX, particularly in the upper regions of the stratosphere, would result in a large decrease in the ozone column. The committee attempts here to give only a brief explanation of the manner in which NOX causes ozone reduction in the baseline and excursion cases.
|
From page 114... ...
The relatively slow development of the ozone minimum reflects primarily the slow upward transport of NOX to regions where the odd oxygen destruction rates are greater. The 8500-Mt excursion scenario would place additional large amounts of NOX at elevations up to about 37 km due to the use of much larger
|
From page 115... ...
The complex set of chemical reactions that control stratospheric ozone concentrations constitutes a system in which the dependency of ozone reductions amounts on NO injection amounts is somewhat nonlinear. These effects were discussed in the NRC (1975)
|
From page 116... ...
has studied short-term chemical and radiative effects of injections of NO into the stratosphere by nuclear weapons. The particular problem he addresses is the Ozone hole." Rapid heating of portions of the stratosphere containing high concentrations of NO2, with subsequent mixing throughout the heated and destabilized volume, causes the ozone hole, which is a large reduction in the ozone column abundance distributed over most of the vertical extent of the stratosphere, but confined laterally.
|
From page 117... ...
The assessment of global effects of perturbing trace substances on stratospheric ozone has caused much effort to be expended in attempting to estimate error limits on calculated ozone reductions. Yet after more that a decade of experience in this exercise the most recent assessment by the NRC (1984a)
|
From page 118... ...
changes in tropospheric dynamics and precipitation rates, which in turn affect the lifetimes of the relevant chemical species. The generalized mechanism of photochemical smog formation includes the critical reaction sequence ROO + NO ~ NO2 + RO NO2 + he ~ NO + O O + O2 + M ~ O3 + M where R can be a hydrogen atom or any organic radical and M is any molecule.
|
From page 119... ...
Connell (Lawrence Livermore National Laboratory, private communication, 1983) have investigated the tropospheric composition changes associated with the baseline scenario using a one-dimensional model of tropospheric photochemistry.
|
From page 120... ...
In addition to the reduced sunlight and loss of OH on particulate surfaces, OH concentrations would be reduced by combination with NO2 to form nitric acid: OH + NO2 ~ M ~ HNO3 + M In addition to the increased burden of toxic chemicals as the result nuclear war fires, one would expect large increases in the concentrations of many reduced compounds for two reasons: (1) the lifetimes of many compounds would be increased by large factors due to reduced concentrations of OH and other oxidants, and (2)
|
From page 121... ...
Considering that biogenic emissions of hydrogen sulfide are comparable in magnitude to DMS and that there would also be emissions from dimethyl disulfide and methyl mercaptan, for which emission factors are not well known, it appears likely that following nuclear war, the total concentration of reduced sulfur compounds in the troposphere would accumulate to a few parts-per-billion by volume. Although these are not toxic levels, at least for short-term exposure to humans, it is noteworthy that the threshold for smell in humans has been found to be in the ranges 0.9 to 8.5 ppbv for H2S and 0.1 to 3.6 ppbv for (CHRIS.
|
From page 122... ...
However, when mixed uniformly throughout the lower 9 km of the atmosphere and over half of the northern hemisphere, the atmospheric concentration of asbestos is calculated to be about 0.3 fibers per cubic centimeter for each teragram of asbestos released. This calculation uses the conversion factor used in epidemiological studies in which it is assumed that 1 fiber would be detected by phase contrast light microscopy for every 30 x 10-12 g of suspended asbestos.
|
From page 123... ...
Raemdonck (1983) Dimethyl sulfide in the surface ocean and the marine atmosphere: A global view.
|
From page 124... ...
Effects of nuclear explosions on stratospheric nitric oxide and ozone.
|
From page 125... ...
National Research Council (1982) Causes and Effects of Stratospheric Ozone Reduction: An Update.
|
From page 126... ...
Paper 82-8,4 presented at the 75th Annual Meeting, Air Pollution Control Association, New Orleans, La .
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.