Modeling Infrared Glow Above Thunderstorms
Abstract
An investigation of the effect of thundercloud charging on electric fields in the middle atmosphere has led to the prediction that heating of electrons in the D-region should occur over time scales of minutes or longer. We have studied the effect of this heating on the excitation of vibrational states of N2 and CO2. Because of the quasi-steady nature of the excitation, it is possible to perform radiative-transfer calculations and determine that populations of the infrared-active V3 states of CO2 are substantially enhanced in the region at and above 75 km, given a charge distribution of sufficient magnitude in the upper troposphere. The resulting infrared 'glow' is predicted to be as much as 100% above the limb background in such cases. MWIR sensors can therefore be expected to measure increased radiance in the CO2 bands when viewing the mesosphere in the vicinity of very large thunderstorm complexes. The limited spatial extent of the excitation will also result in enhanced MWIR radiance structure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 23, 1998
- Accession Number
- ADA401250
Entities
People
- Peter P. Wintersteiner