Insights into middle atmospheric hydrogen chemistry from analysis of MAHRSI OH observations

摘要: Observations of mesospheric and upper stratospheric OH made from space by the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) in November 1994 August 1997 have opened a new window on study middle atmospheric hydrogen chemistry. The MAHRSI observations ultraviolet fluorescence allowed more detailed testing models odd-hydrogen (HO x = H + HO 2 ) chemistry, its role catalytic destruction ozone, over wider range altitudes than ever before. Models using standard photochemical theory overestimate observed abundance 25 to 35% throughout mesosphere, yet stratosphere underestimate nearly 20%. sharp transition at stratopause cannot be understood terms chemistry or any previously proposed modifications that theory. Perhaps most intriguing result modeling data is confirmation narrow layer water vapor near 70 km had been Halogen Occultation Experiment (HALOE) Upper Atmospheric Research Satellite (UARS). existence this explained gas phase these furthermore requires local source O. This may suggest heterogeneous (e.g., surface recombination O meteoric dust form O) plays an important mesosphere. column are general agreement with both balloon infrared extrapolated above 40 altitude, high altitude aircraft 2.5 THz observations, thus resolve earlier disagreement among measurements. Taken together, results model atmosphere incomplete.