Measurements of Atmospheric Composition Using Infrared Techniques

点击翻译按钮获取中文摘要

A research program is proposed which will yield additional experimental data pertinent to two environmental problems of current interest. These problems are the possible perturbation of the stratospheric ozone layer by man's activities and the possible change in climate caused by the increase in atmospheric concentration of radiatively active compounds (CO2, CH4, N2O, etc). Data pertinent to these two problems will be obtained by the analysis of infrared solar spectra obtained from the ground at various locations (Denver, Mauna Loa and Lauder, New Zealand) at various times of the year. Solar spectra will be obtained at various altitudes and solar zenith angles by means of balloons. The ground based spectra will be used to study the temporal and spatial variability of the stratospheric column density of HCl, HNO3, ClONO2. They will also be used to compare the absorption features due to CH4, CO2, N2O, O3 and H2O with theoretical calculations of the same feature based on our knowledge from other measurements (GMCC, Dobson, rawinsonde, etc). Differences between the calculated and observed spectra will be examined to determine the cause of the disagreement. The spectra obtained during the balloon flight will be used to determine the distribution of various constituents with altitude particularly in the stratosphere. Profile data will be obtained for HCl, HNO3, ClONO2, NO, NO2, HNO4, CH4 and N2O and the high resolution spectra will be examined for absorption due to other compounds which are predicted to be present (HOCl, H2O2) but have not been observed in solar spectra obtained at lower resolution. Atmospheric emission spectra will be obtained both from the ground and from various altitudes up to 40 km using a balloon-borne spectrometer system. Spectra will be obtained while viewing various angles close to the earth's limb and the nadir. These spectra will be used to obtain altitude profile data for NO2, N2O5, ClONO2, HNO3, O3, and H2O. The change in concentrations of these compounds with time during sunrise and/or sunset will also be measured.