Open AccessNon‐LTE effects on retrieval of temperature from the CO 2 laser bands using CIRRIS 1A data
Author(s) -
Miller Steven M.,
Winick Jeremy,
Snell Hilary E.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd901111
Subject(s) - radiance , stratosphere , environmental science , remote sensing , kinetic energy , infrared , atmospheric sciences , instrumentation (computer programming) , laser , mean kinetic temperature , meteorology , physics , materials science , atomic physics , optics , geology , computer science , quantum mechanics , operating system
It is well known that in the upper stratosphere and lower mesosphere, the CO 2 laser band (00011–10001) transitions are populated by both local thermodynamic equilibrium (LTE) and non‐LTE mechanisms. Examination of infrared (IR) limb emission measurements from the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS 1A) experiment clearly illustrates this effect. The presence of non‐LTE emissions, if left unaccounted for, will severely degrade the retrieval of kinetic temperature profiles. We have applied a non‐LTE compensation technique whereby the non‐LTE component is modeled and the resulting non‐LTE radiance is subtracted from the measured radiances. The kinetic temperature profile is then retrieved utilizing the modified data. As a means of validating this approach, we have compared the resulting temperature profiles to ones retrieved using the 792 cm −1 Q branch of CO 2 , the (11101–10002) transition, which is not significantly affected by non‐LTE excitation.