Use of CRISTA mesopause region temperatures for the intercalibration of ground-based instruments

Abstract

Most available ground-based (GB) techniques for measuring temperatures in the upper mesosphere to lower thermosphere (or mesopause region) have systematic errors that are comparable to those of orbiting instruments. Determining these unknown biasses would normally require colocated observations that are only seldom feasible. Satellite measurements can be used as a ''transfer standard'' between GB observations that are not colocated. In this context, even with a reproducible or known bias in the satellite data, the comparison is still meaningful. Since Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures cover the mesopause region with very good accuracy (statistical errors do not exceed 1.5 K and systematic uncertainties range from about 3-7.5 K), they are quite suitable for this purpose. Because of the nearly constant precision over the height range of interest, also rotational temperatures of airglow emissions from different altitudes like the OH and O 2 bands (or the OI 558 nm line) can be successfully compared with each other. In spite of the limited number of overpasses during the relatively short CRISTA missions, the feasibility of such an intercalibration is demonstrated for widely separated GB sites. Here, the results obtained for GB measurements at eight different sites, using CRISTA-1 and CRISTA-2 data, are presented. For OH temperatures, the standard deviation between the different instruments is only 5.4 K, confirming previous estimates. r

A comparison of ground-based hydroxyl airglow temperatures with SABER/TIMED measurements over 23° N, India

“…The ground-based temperatures were 4-5 K higher than SABER values, similar to earlier reports (von Savigny et al, 2004;Oberheide et al, 2006;Scheer et al, 2006;López-González et al, 2007;Mulligan and Lowe, 2008). As T OH derived from Meinel band line intensities strongly depend on the choice of transition probabilities (French et al, 2000), T OH were also derived using the transition probabilities given by Mies (1974), Turnbull and Lowe (1989) and Goldman (1998); however, the mean difference between T OH and SABER measurements increased from 3 to 15 K with their use.…”

“…A difference of 7-12 K between T OH and T 2.0 was observed in a large number of remaining coincidences. Scheer et al (2006) reported the difference of 0.2-11.5 K between the ground-based T OH and CRISTA temperatures. As a trial, OH-equivalent temperatures were calculated using an intermediate weighing function, viz.…”

“…Several space-borne instruments like the Microwave Limb Sounder (MLS) on the Aura satellite; Atmospheric Chemistry Experiment -Fourier Transform Spectrometer (ACE-FTS) on SciSat-1; Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) on Environmental Satellite (ENVISAT); Solar Occultation for Ice Experiment (SOFIE) on the AIM satellite; Optical, Spectroscopic, and Infrared Remote Imaging System (ORISIS) on the Odin satellite; the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) satellite instrument, and Sounding of the Atmosphere by Broadband Emission of Radiation (SABER) on-board the TIMED mission satellite have also contributed immensely to our knowledge of the temperature field of the MLT region (von Savigny et al, 2004;Scheer et al, 2006;Xu et al, 2007;Mulligan and Lowe, 2008;French and Mulligan, 2010;Sheese et al, 2011;García-Comas et al, 2012, 2014and references cited therein).…”

“…At Wuppertal (51 • N), Oberheide et al (2006) found OH (3, 1) temperatures to be systematically warmer than the SABER measurement (on average by 7.5 K) during [2003][2004][2005]. Using the mesopause region temperature measurements by the CRISTA-1 and CRISTA-2 missions, Scheer et al (2006) performed such a comparison of groundbased OH temperature measurements at eight sites (spread over 38-63 • N and 32-69 • S). López-González et al (2007) reported the measurements of OH (6, 2) Meinel band and O 2 (0, 1) atmospheric band temperatures with Spectral Airglow Temperature Imager (SATI) at the Sierra Nevada Observatory (37 • N) and their comparison with SABER observations.…”

Seasonal variations of the nighttime O(1S) and OH (8‐3) airglow intensity at Adelaide, Australia

“… Nominal peak emission heights are from Baker et al [] for OH, McDade [] for O 2 , and Scheer et al [] for OI.…”