Quenching of CO2(ν2) by O: New Results and Analysis

Details Quenching of CO2(ν2) by O: New Results and Analysis Quenching of CO2(ν2) by O: New Results and Analysis

Dec 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005agufmsa11a0222d&link_type=abstract

American Geophysical Union, Fall Meeting 2005, abstract #SA11A-0222

Physics

0317 Chemical Kinetic And Photochemical Properties, 0340 Middle Atmosphere: Composition And Chemistry, 0342 Middle Atmosphere: Energy Deposition (3334), 0355 Thermosphere: Composition And Chemistry, 0358 Thermosphere: Energy Deposition (3369)

Scientific paper

New results from ongoing laboratory measurements of CO2(ν2) + O vibrational energy transfer (VET) will be presented. The process is a key contributor to both the CO2 15-μm emission intensity and to upper atmospheric cooling in the 75-120 km altitude range. A 266-nm laser pulse photolyzes O3, producing O atoms and initiating a temperature jump, while transient diode laser absorption spectroscopy is used to monitor the CO2(ν2) level population. We report the latest measurement results, including improvements in the experiment that have mitigated vibrational cascading effects, and the development of a powerful global kinetic fitting routine to allow the simultaneous determination of the appropriate rate parameters from a large body of data. Predictions of upper atmospheric density and temperature are sensitive to the input value of the CO2(ν2) + O relaxation rate constant ko(ν2), including its temperature dependence. Aeronomic models imply that increasing CO2 levels from anthropogenic sources will cause the thermosphere to cool and contract over time. The model results are supported by analyses of satellite orbital motion data over the past 40 years, which are consistent with a few percent thermospheric density decrease per decade. This has important implications for spacecraft drag and orbital longevity. It also provides an interesting connection between a molecular-level parameter, the CO2 + O VET efficiency, and the macroscopic effects of atmospheric density and temperature.

Affiliated with

Also associated with

No associations

Rating

Quenching of CO2(ν2) by O: New Results and Analysis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quenching of CO2(ν2) by O: New Results and Analysis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quenching of CO2(ν2) by O: New Results and Analysis will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-752296