Laboratory Investigation of Vibration-Level Dependent Production of Oxygen via Energy Transfer from Nitrogen

University Of Maryland, College Park, College Park MD

Investigators

Abstract

ATM-9910914 Ginter, Marshall Using reasonable assumptions based on laboratory data, atmospheric modelers calculate significantly more (factors of 3 to 4) O (1S ) than is observed in aurora and the dayglow [Bucsela et al. 1998]. Either there is a fundamental problem with the interpretation of previous experimental data or an important process (or processes) is (are) being neglected in current atmospheric models. The proposed research addresses this problem using new experimental techniques. The subsequent rates and pathways for loss of N2 (A) and production of O(1S) will be monitored directly using two-photon laser ionization to determine instantaneous changes in N2(A) and O(1S) concentrations and the branching ratios for O(1S) production. These measurements will be made for temperatures near 300 K, which are appropriate for comparison with existing laboratory measurements, and in the ~ 400- 600 K range appropriate to the lower thermosphere. Resulting data will be used (a) to determine reaction rate coefficients and O(1S) production efficiencies and branching ratios, (b) to identify the major mechanisms involving O(1S) production via N2(A) in the atmosphere, and (c) to provide critical input data for future airglow and auroral models.