Showing papers by "Ulrich Platt published in 1995"
TL;DR: In this article, a review of the relationship between the laboratory investigations and the atmospheric studies is presented, focusing on gas-phase processes of halogen oxides and their precursors in the laboratory and the atmosphere.
152 citations
TL;DR: In 1992, seven groups from seven countries met in Lauder, New Zealand, to intercompare their remote sensing instruments for the measurement of atmospheric column NO2 from the surface as discussed by the authors.
Abstract: During the period May 12–23, 1992, seven groups from seven countries met in Lauder, New Zealand, to intercompare their remote sensing instruments for the measurement of atmospheric column NO2 from the surface. The purpose of the intercomparison was to determine the degree of intercomparability and to qualify instruments for use in the Network for the Detection of Stratospheric Change (NDSC). Three of the instruments which took part in the intercomparison are slated for deployment at primary NDSC sites. All instruments were successful in obtaining slant column NO2 amounts at sunrise and sunset on most of the 12 days of the intercomparison. The group as a whole was able to make measurements of the 90° solar zenith angle slant path NO2 column amount that agreed to about ±10% most of the time; however, the sensitivity of the individual measurements varied considerably. Part of the sensitivity problem for these measurements is the result of instrumentation, and part is related to the data analysis algorithms used. All groups learned a great deal from the intercomparison and improved their results considerably as a result of this exercise.
75 citations
TL;DR: In this article, a shipboard DOAS (Differential Optical Absorption Spectroscopy) measurements of stratospheric NO2 and O3 vertical column abundances were obtained between 50°N and 50°S during October and November 1990, before the eruption of Mt Pinatubo.
Abstract: The present paper reports on shipboard DOAS (Differential Optical Absorption Spectroscopy) measurements of stratospheric NO2 and O3 vertical column abundances. The data were obtained between 50°N and 50°S during October and November 1990, before the eruption of Mt. Pinatubo. The daily measurements were made during morning and evening twilight. The retrieved column abundances were averaged over a solar zenith angle (SZA) range of 87° to 91°, for both NO2 measured in the visible wavelength region and for O3 measured in the UV. The instrumentation and the data evaluation technique are briefly discussed.
In the Northern Hemisphere (autumn) the NO2 vertical column abundances show a steady decrease from 50°N to the equator, while in the Southern Hemisphere (spring) the corresponding increase with latitude is both more pronounced and more variable. Depending on latitude, the measured mean am/pm ratios are between 0.55 and 0.63, generally consistent with the pre-Pinatubo overnight conversion of NO2 to N2O5.
Within the estimated error of our DOAS measurements, the retrieved O3 vertical column amounts are in good agreement with the TOMS data. Both data sets show a slightly different longitudinal distribution than expected from the O3 climatology.
13 citations