Measurements of Hydroxyl Column Abundances: Implications for the Photochemistry of the Middle Atmosphere

9730010 Minschwaner这个项目将延续来自科罗拉多州Fritz Peak的二十年来羟基自由基柱丰度的记录。羟基自由基是地球大气中最活跃的化学成分之一，在平流层臭氧的化学收支中起着直接作用，并调节活性和稳定的氯和氮化合物之间的转化。这些是使用定制设计的高分辨率光度产品光谱仪对308 nm处的太阳光的共振吸收进行的地面测量。将使用位于新墨西哥州采矿和技术研究所的第二台仪器进行更多的观测，重点是新的仪器和分析程序。在涉及太阳翼光谱多普勒频移的OH辅助测量中，将努力提高信噪比。将全面分析光谱仪的杂散光特性，包括与其他仪器的比较，例如航天飞机上的MAHRSI仪器和喷气推进实验室的FTUV测量。将通过开发NCAR ROSE模式的一维版本和测试各种中层机制，继续开展分析工作。目前的光化学模型不能再现观测到的OH柱丰度的地理、昼夜、季节和长期变化。

9730010 Minschwaner This project will extend the twenty-year record of the hydroxyl radical (OH) column abundances from Fritz Peak, CO. The hydroxyl radical is one of the most chemically active constituents in the Earth's atmosphere, playing a direct role in the chemical budget of stratospheric ozone and mediating the transformation between reactive and stable compounds of chlorine and nitrogen. These are ground-based measurements of the resonant absorption of sunlight at 308 nm using a custom designed, high resolution-luminosity product spectrometer. Additional observations will be made using a second instrument located at the New Mexico Institute for Mining and Technology, with emphasis on new instrumentation and analysis procedures. Efforts will be made to improve the signal to noise ratio in auxiliary measurements of OH which involve the Doppler shift in solar limb spectra. A comprehensive analysis will be undertaken of the stray light characteristics of the spectrometers, including comparisons to other instruments, such as the MAHRSI instrument on the Space Shuttle and the FTUV measurements at JPL. Analysis work will be continued through the development of a 1-D version of the NCAR ROSE model and testing of various mesospheric mechanisms. Current photochemical models fail to reproduce the observed geographic, diurnal, seasonal, and secular changes observed in the OH column abundances.