A new mechanism for OH vibrational relaxation leading to enhanced CO2 emissions in the nocturnal mesosphere

作者：Sharma Ramesh D^*; Wintersteiner Peter P; Kalogerakis Konstantinos S

来源：Geophysical Research Letters, 2015, 42(11): 4639-4647.

DOI：10.1002/2015GL063724

• nocturnal mesosphere
• 4
• 3 mu m emission
• CO2
• OH
• O
• O(D-1)

On the basis of experimental and theoretical studies, this paper proposes a new mechanism that contributes to nocturnal 4.3 mu m CO2 emissions. It suggests that collisions of ground state O atoms with highly vibrationally excited OH(v), produced by the reaction of H with O-3, remove a substantial fraction of the OH(v) vibrational energy by a fast, spin-allowed, multiquantum vibration-to-electronic energy transfer (ET) process that generates O(D-1): OH(v5)+O(P-3)OH(0vv-5)+O(D-1). The electronically excited O(D-1) atom is subsequently deactivated by collisions with N-2 in a fast spin-forbidden ET process that leaves the N-2 molecule with an average of 2.2 vibrational quanta. Finally, the vibrational excitation of N-2 is transferred by a fast, near-resonant vibration-to-vibration ET process to the asymmetric stretch (v(3)) mode of CO2, which promptly radiates near 4.3 mu m.

• 出版日期2015-6-16