Measurements of stratospheric HO2 and NO2 by matrix isolation and ESR spectroscopy |
| |
| Authors: | M Helten W Pätz M Trainer H Fark E Klein D H Ehhalt |
| |
| Institution: | (1) Institut für Chemie 2: Chemie der belasteten Atmosphäre, Kernforschungsanlage Jülich GmbH, Postfach 1913, D-5170 Jülich, F.R. Germany;(2) Present address: Aeronomy Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, 80303 Boulder, Colorado, U.S.A.;(3) Present address: Institut für Chemie 3: Atmosphärische Chemie, Kernforschungsanlage Jülich GmbH, Postfach 1913, D-5170 Jülich, F.R.G. |
| |
| Abstract: | Vertical profiles of stratospheric HO2 and NO2 concentrations were determined using matrix isolation and ESR. Up to 10 different samples per flight were collected in situ by a balloon borne cryosampler. Free radicals and trace constituents which are condensable at 68 K are trapped in a polycristalline H2O or D2O matrix. After collection, the samples are stored at a temperature below 83 K until they are analysed in the laboratory by X-band ESR spectroscopy at 4 K. The HO2 and NO2 were identified and calibrated by comparison with standard samples collected in the laboratory under typical stratospheric sampling conditions. From several flights over Southern France (44°N) we obtained two profiles of the stratospheric NO2 mixing ratio. One, from 21 October 1982, agrees well with previous measurements. The other, from 8 October 1981, is lower by one order of magnitude. The few HO2 data obtained around 35 km altitude agree with previous measurements. An isolated measurement at 17 km altitude is one order of magnitude higher than the model predicted HO2 concentration. |
| |
| Keywords: | Stratospheric photochemistry HO2
- NO2
+in situ data vertical profiles |
| 本文献已被 SpringerLink 等数据库收录！ |
|
