Negative stratosphere

More complex ions are created lower in the atmosphere. Almost all ions below 70-80 km are cluster ions. Below this altitude range free electrons disappear and negative ions fonn. Tln-ee-body reactions become important. Even though the complexity of the ions increases, the detemiination of the final species follows a rather simple scheme. For positive ions, fomiation of H (H20) is rapid, occurring in times of the order of milliseconds or shorter in the stratosphere and troposphere. After fomiation of H (H20), the chemistry involves reaction with species that have a higher proton affinity than that of H2O. The resulting species can be... 

Viggiano A A and Arnold F 1981 The first height measurements of the negative ion composition of the stratosphere Pianet. Space Sc/. 29 895-906... 

Arnold F and Henschen G 1978 First mass analysis of stratospheric negative ions Nature 257 521-2 Eisele F L 1989 Natural and anthropogenic negative ions in the troposphere J. Geophys. Res. 94 2183-96 Oka T 1997 Water on the sun—molecules everywhere Science 277 328-9... 

Possible negative environmental effects of fertilizer use are the subject of iatensive evaluation and much discussion. The foUowiag negative effects of fertilizer usage have been variously suggested (113) a deterioration of food quaUty the destmction of natural soil fertility the promotion of gastroiatestiaal cancer the pollution of ground and surface water and contributions toward the destmction of the ozone layer ia the stratosphere. 

Figure 9.55a shows the results of single-particle analysis (see Chapter ll.B.4a) of a typical particle in the upper troposphere (Murphy et al., 1998). In the negative ion spectra, a variety of fragments due to organics are observed, along with sulfates and some halogens. In other particles, soot and minerals were also common constituents. For comparison, Fig. 9.55b shows that a typical particle in the stratosphere is primarily sulfate (see Chapter 12.C.5). 

Table 11.4 summarizes measurements of various species in the stratosphere and troposphere by mass spectrometry through the early 1990s (Viggiano, 1993, and references therein). The altitude at which they were measured and the concentration ranges are shown, as well as whether they were detected using positive or negative ions (see later discussion). 

Similarly, Fig. 13.12 shows the percentage deviation in regionally averaged stratospheric ozone for North America, Europe, and the Far East after variations due to the solar cycle, seasonal variations, the QBO, and atmospheric nuclear tests were subtracted out. Negative deviations are consistently seen in recent years, suggesting a long-term trend on top of the natural variability (Stolarski et al., 1992). 

Arnold, F., and G. Henschen, First mass analysis of stratospheric negative ions, Nature, 275, 521-522,... 

Fig. 4. The ionized regions of the Earth s atmosphere. The F, E and D regions are designated according to the ledges observed in the electron density. Typical altitudinal profiles of the various positive ion densities in the positive ion-electron plrtsma (from Refs.20 and 2I)) are also shown. The negative ion types in the positive ion-negative ion plasma of the lower D-region are known but the detail altitudinal profiles of density are not well characterised and so only the approximate total negative ion density, N, (dashed line) as obtained from Refs.22) and 23) is shown. The profiles of the electron density, Ne, and the total positive ion density, N+, are also included. It is assumed that quasi-neutrality exists throughout the atmosphere, that is Ne N+ in the thermosphere, Ne + N N+ in the mesosphere, and N N+ in the stratosphere and troposphere...

The negative ion content of the stratospheric plasma is even less certain. The only data so far available are those obtained very recently by Arnold 62 which are as yet... 

The processes by which ions are lost in the stratosphere and the troposphere are not completely understood due to a sparcity of laboratory data on ionic recombination. It is most likely that mutual neutralization of cluster ions [reaction (9)] will be the primary loss mechanism in the upper stratosphere, with the process of collision-enhanced (ternary) recombination becoming increasingly important at lower altitudes (Sect. 3.2.5). In the presence of aerosols (liquid or solid droplets), loss of both positive and negative cluster ions from the gas phase can occur by attachment to the aerosol surfaces 85 86) (see Sect. 4). 

At lower altitudes where significant concentrations of ozone exist, O- ions are generated by dissociative attachment [reaction (10b)]. These electron attachment processes and the laboratory techniques used to determine their rate coefficients were reviewed some time ago by Phelps1 S4 In the stratosphere and troposphere, negative ions can also be generated by dissociative attachment reactions of thermalised electrons with pollutants1 s5,1561 such as the freons e.g. 

Fig. 8. A generalized scheme describing the ion chemistry of the stratosphere and troposphere. The symbols are as in Fig. 7 but additionally with P representing bases such as NH3 and NaOH and (acids) representing HNO3, H2SO4, HC1 etc. Those parts of the positive ion schemes involving NO+ and NOf and the negative ion scheme originating from O- are considered to be of lesser importance in the overall chemistry...

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