Measurements of the NO x ‐O3 photostationary state at Niwot Ridge, Colorado

The photostationary state (PSS) involving NO, NO2, and O3 has been studied at a site located in the Colorado mountains. During the daytime in summer the concentration of NO2 relative to the concentration of NO is greater than expected from the PSS. These results indicate that an additional oxidant OX other than O3 is converting NO to NO2. The level of OX depends on season, NOx (NO + NO2) concentration, and solar UV intensity. The maximum OX levels occur for an NOx mixing ratio of about 0.4 parts per billion by volume (ppbv). For NOx mixing ratios below 0.1 ppbv, no substantial imbalance in the PSS is observed. For NOx concentrations between 0.25 and 1.0 ppbv, the OX level depends linearly on solar UV intensity. In the winter the level of OX is much lower than in the summer for all NOx concentrations and solar UV intensities. The nature of OX, as indicated from the NOx-catalyzed formation of O3, is examined.

[1]  S. C. Liu,et al.  Background ozone and anthropogenic ozone enhancement at niwot ridge, Colorado , 1986 .

[2]  D. Fahey,et al.  A calibrated source of N2O5 , 1985 .

[3]  C. J. Hahn,et al.  NOx measurements in clean continental air and analysis of the contributing meteorology , 1984 .

[4]  P. Zimmerman,et al.  Nonmethane hydrocarbons in remote tropical, continental, and marine atmospheres , 1984 .

[5]  Ø. Hov,et al.  Measurement and modeling of the concentrations of terpenes in coniferous forest air , 1983 .

[6]  D. Albritton,et al.  Measurement of monoterpene hydrocarbons at Niwot Ridge, Colorado , 1983 .

[7]  Jennifer A. Logan,et al.  Nitrogen oxides in the troposphere: Global and regional budgets , 1983 .

[8]  N. Washida,et al.  Laser induced fluorescence of IO radicals and rate constant for the reaction of IO+NO , 1983 .

[9]  W. Stockwell,et al.  Deviations from the O3–NO–NO2 photostationary state in tropospheric chemistry , 1983 .

[10]  S. C. Liu,et al.  A study of ozone in the Colorado mountains , 1983 .

[11]  D. Stedman,et al.  The NO/NO2/O3 Photostationary State in Claremont, California , 1983 .

[12]  D. L. Albritton,et al.  The measurement of the photodissociation rate of NO2 in the atmosphere , 1983 .

[13]  A. Lloyd,et al.  An updated chemical mechanism for hydrocarbon/NOx/SO2 photooxidations suitable for inclusion in atmospheric simulation models , 1982 .

[14]  S. Wofsy,et al.  Tropospheric chemistry: A global perspective , 1981 .

[15]  J. W. Drummond,et al.  Tropospheric profiles of NOx , 1981 .

[16]  Douglas D. Davis,et al.  Iodine - Its possible role in tropospheric photochemistry , 1980 .

[17]  R. B. Harvey,et al.  Measurements of oxides of nitrogen and nitric acid in clean air , 1980 .

[18]  D. Kley,et al.  On the origin of tropospheric ozone , 1980 .

[19]  D. Kley,et al.  Chemiluminescence detector for NO and NO/sub 2/ , 1980 .

[20]  J. W. Drummond,et al.  Nitric oxide measurements in the equatorial Pacific region , 1979 .

[21]  P. Crutzen.  A discussion of the chemistry of some minor constituents in the stratosphere and troposphere , 1973 .

[22]  R. Barry.  A climatological transect on the east slope of the Front Range , 1973 .

[23]  H. Levy.  Normal Atmosphere: Large Radical and Formaldehyde Concentrations Predicted , 1971, Science.

[24]  P. Leighton,et al.  Photochemistry of Air Pollution , 1961 .