SABER observations of mesospheric temperatures and comparisons with falling sphere measurements taken during the 2002 summer MaCWAVE campaign

Abstract

The SABER instrument was launched onboard the TIMED satellite in December 2001. Vertical profiles of kinetic temperature (Tk) are derived from broadband measurements of CO2 15 μm limb emission, in combination with measurements of CO2 4.3 μm limb emission used to derive CO2 volume mixing ratio (vmr). Infrared emission from the CO2 ro‐vibrational bands are in non‐local thermodynamic equilibrium (non‐LTE) in the mesosphere and lower thermosphere (MLT), requiring new radiation transfer and retrieval methods. In this paper we focus on Tk and show some of the first SABER observations of MLT Tk and compare SABER Tk profiles with rocket falling sphere (FS) measurements taken during the 2002 summer MaCWAVE campaign at Andøya, Norway (69°N, 16°E). The comparisons are very encouraging and demonstrate a significant advance in satellite remote sensing of MLT limb emission and the ability to retrieve Tk under extreme non‐LTE conditions.

Observations and Modeling of the Upper Mesosphere: Mesopause Characteristics, Inversion Layers, and Bores

“…This effort was concurrent with our investigation of MLT temperature-inversion layers, described below [also, Picard et al, 2004;Winick et al, 2004]. The layer-locating algorithm we developed for that purpose required finding the mesopause as a first step.…”

Properties of the Long-Term Oscillations in the Middle Atmosphere Based on Observations from TIMED/SABER Instrument and FPI over Kelan

“…In the mesosphere, the effects of non-local thermodynamic equilibrium (NLTE) must be considered in the retrieval scheme [32,33].…”

Kinetic temperature and carbon dioxide from broadband infrared limb emission measurements taken from the TIMED/SABER instrument

“…During daytime conditions, Tk and CO 2 are retrieved simultaneously from SABER's CO 2 15 µm and CO 2 4.3 µm radiometer channel measurements, respectively (Mertens et al, 2002). During nighttime, Tk is retrieved from the SABER 15 µm channel measurements and the CO 2 concentration is determined from a TIME-GCM climatological database (Mertens et al, 2001;Roble, 1995).…”

“…The non-LTE and atmospheric input parameters included in the study by Mertens et al were the collisional quenching rate of CO 2 (ν 2 ) by atomic oxygen, the atomic oxygen concentration, and the CO 2 vmr. The source of CO 2 vmr during the day is from the simultaneous Tk/CO 2 retrieval (Mertens et al, 2002). At night, CO 2 vmr is obtained from a TIME-GCM climatological database (Roble, 1995).…”