Ozone absorption bands

Halogen oxide radicals such as CIO and BrO are important reactive intermediates in the catalytic cycles of ozone destruction in the middle and upper stratosphere. The first absorption band CIO(/l211 <— X2 I) starts from 318 nm and has a series of vibronic bands that converge to a broad continuum at wavelengths shorter than 264nm (Fig. 8).98-101 In this continuum region four dissociation pathways are thermodynamically possible,33... 

Dobson spectrophotometer spect A photoelectric spectrophotometer used in the determination of the ozone content of the atmosphere compares the solar energy at two wavelengths in the absorption band of ozone by permitting the radiation of each to fall alternately upon a photocell. dab-san Spek-tro-fa tam-ad-ar docosane org chem C22H46 A paraffin hydrocarbon, especially the normal isomer CH3(Cf2l2)2oCH3. dak-a,san ... 

Recent discussions of stratospheric chemistry have dealt with the effect of freons on ozone balance through a Cl/ClO catalytic destruction of ozone. The fundamental absorption band of CIO is measured to be at 11 /xm. Isotopically substituted CO2 laser based OA absorption measurement technique should allow us to carry out fundamental measurements on CIO and its diurnal variation in the stratosphere to provide yet another important parameter (in addition to NO above) in the stratospheric ozone chemistry. 

Another approach is to obtain tropospheric ozone levels using satellite data as described in Chapter 13.C (e.g., see Fishman et al., 1990 and Munro et al., 1998). Vertical tropospheric ozone profiles can be extracted using satellite measurements of backscattered solar radiation at wavelengths where ozone has strong absorption bands. 

Huffman117 has observed the intense absorption bands lying between 830 and 900 A in the photolysis products of ozone, thus confirming that metastable oxygen is a photolysis product. 

ABSORPTION BAND. A range of wavelengths (or frequencies) in the electromagnetic spectrum within which radiant energy is absorbed by a substance. When the absorbing substance is a polyatomic gas, an absorption band actually is composed of a group of discrete absorption lines, which appear to overlap. Each line is associated with a particular mode of vibration or rotation induced in a gas molecule by the incident radiation. The absorption bands of oxygen and ozone are often referred to in the literature of atmospheric physics. 

From 200 to 242 nm, the 02 absorption, which is related to the Herzberg continuum with low absorption cross section, occurs in the stratosphere. In this spectral region, the ozone absorption must be introduced since the 03 Hartley band is characterized by high values of the absorption cross section between 200 and 300 nm. The simultaneous absorption by 02 and 03 must be considered in the stratosphere, whereas the O3 absorption is practically negligible in the mesosphere since the total number of absorbing ozone molecules is small. 

Johnson, B.R. and Kinsey, J.L. (1987). Time-dependent analysis of the Hartley absorption band and resonance Raman spectra in ozone, J. Chem. Phys. 87, 1525-1537. 

Since many atmospheric pollutants such as ozone have absorption bands in the ultraviolet, measurements have also been performed in this spectral region. Recently, it was shown that phase locking within the filaments results in enhanced third harmonic generation [46]. Then, the build-up of the ultraviolet supercontinuum was characterized over both the laboratory and the atmospheric scales. The UV-visible part of the continuum measured in the laboratory with a single filament is presented in Fig. 15.7. At the beginning of filamentation, a third harmonic band with 20 nm bandwidth is generated around 270 nm. Two meters further, the intensity of the third harmonic is reduced and a plateau appears in the UV-Visible region be-... 

Ozone occurs in small quantities in the atmosphere as is evidenced by certain absorption bands in solar and stellar spectra.1 It is also present in certain natural waters in sufficient quantity to be recognisable by the smell.2... 

Note 5. Insolubles are present when Klason lignin or wood meal is used. After a 40-min ozonation of wood meal, examination of the insoluble residue (in KBr) by FTIR showed the absence of characteristic lignin absorption bands. 

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