Identification

Title

CO2(v2)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere

Abstract

Among the processes governing the energy balance in the mesosphere and lower thermosphere (MLT), the quenching of CO₂(v₂) vibrational levels by collisions with O atoms plays an important role. However, there is a factor of 3-4 discrepancy between the laboratory measurements of the CO₂-O quenching rate coefficient, kVT, and its value estimated from the atmospheric observations. In this study, we retrieve kVT in the altitude region 85-105 km from the coincident SABER/TIMED and Fort Collins sodium lidar observations by minimizing the difference between measured and simulated broadband limb 15 μm radiation. The averaged kVT value obtained in this work is 6.5 ± 1.5 × 10-12 cm3 s⁻¹ that is close to other estimates of this coefficient from the atmospheric observations. However, the retrieved kVT also shows altitude dependence and varies from 5.5 ± 1.1 × 10-12 cm3 s⁻¹ at 90 km to 7.9 ± 1.2 × 10-12 cm³ s⁻¹ at 105 km. Obtained results demonstrate the deficiency in current non-LTE modeling of the atmospheric 15 μm radiation, based on the application of the CO₂-O quenching and excitation rates, which are linked by the detailed balance relation. We discuss the possible model improvements, among them accounting for the interaction of the "non-thermal" oxygen atoms with CO₂ molecules.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7sx6f07

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

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keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

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Temporal reference

Temporal extent

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End position

Dataset reference date

date type

publication

effective date

2012-10-02T00:00:00Z

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Conformity

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version of format

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Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact