Simulation of Earths Atmosphere

Interest in NOx species is inspired by the desire to understand their complex spectroscopic characteristics on a fundamental level, as well as by their importance in the Earth s atmosphere, especially with regard to key processes relating to ozone (O3), hydroxyl radicals, and acid formation [100]. Model calcnlations indicate that background concentrations of NOx in the troposphere may have risen by almost 100%, causing a 20% increase in O3 levels dining much of the year. Beck and Ehhalt [101, 102] reported significant evidence that 30-50% of the NOx in the np-per troposphere is due to aircraft emissions. 

Since MW discharges through N2/O2 in the presence of water are used for simulations [76] of atmospheric chemistry, it would be desirable to examine the effects of water in detail. Therefore, LE lAMS with a flow system were employed to qualitatively detect the product species, paying special attention to the effects of water [105]. The prodncts of an MW discharge in air-like gas mixtures (80% N2, 20% O2, and water) were measnred. The products of the discharge ate molecules that are thought to exist in the atmosphere and are relevant to the study of atmospheric chemistry. 

The product species detected in this simulation study were compared (Table 5.2) with the species detected in field observations [ 106]. It is foimd that the neutral species observed in the laboratory resemble the constituents observed in the Earth s atmosphere. On the basis of this resemblance, it is concluded that the MW discharge-induced chemistry observed in the N2/O2/H2O plasma may be helpful for understanding atmospheric chemistry. Laboratory simulation experiments can yield results directly applicable to the Earth s atmosphere. It should be noted, however, that there are significant differences in the relative amounts of the prodncts, especially for NO and HNO2. The ionic products were compared with those detected by Eisele et al. [107] in a remote desert area of southeastern Arizona and on top of Moimt Washington in New Hampshire. No agreement in terms of the prodncts, except for one species at miz 60. A number of ionic clusters with NO+ and H2O+ produced by gas-phase ion-molecule reactions were detected, bnt the NH + prodncts observed by Eisele were not observed. This difference remains imexplained at this time. The as-yet-nnidentified ionic species at mIz 60 in both stndies is probably NO (NO), which is present with considerable intensity in the plasma at a H2O partial pressure of 1 Pa. It is assumed that some of the ionic prodncts foimd in the simnlation study 

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