[1] The quality of the retrieved temperature-versus-pressure (or T(p)) profiles is described for the middle atmosphere for the publicly available Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) Version 1.07 (V1.07) data set. The primary sources of systematic error for the SABER results below about 70 km are (1) errors in the measured radiances, (2) biases in the forward model, and (3) uncertainties in the corrections for ozone and in the determination of the reference pressure for the retrieved profiles. Comparisons with other correlative data sets indicate that SABER T(p) is too high by 1-3 K in the lower stratosphere but then too low by 1 K near the stratopause and by 2 K in the middle mesosphere. There is little difference between the local thermodynamic equilibrium (LTE) algorithm results below about 70 km from V1.07 and V1.06, but there are substantial improvements/differences for the non-LTE results of V1.07 for the upper mesosphere and lower thermosphere (UMLT) region. In particular, the V1.07 algorithm uses monthly, diurnally averaged CO 2 profiles versus latitude from the Whole Atmosphere Community Climate Model. This change has improved the consistency of the character of the tides in its kinetic temperature (T k ). The T k profiles agree with UMLT values obtained from ground-based measurements of column-averaged OH and O 2 emissions and of the Na lidar returns, at least within their mutual uncertainties. SABER T k values obtained near the mesopause with its daytime algorithm also agree well with the falling sphere climatology at high northern latitudes in summer. It is concluded that the SABER data set can be the basis for improved, diurnal-to-interannual-scale temperatures for the middle atmosphere and especially for its UMLT region.Citation: Remsberg, E. E., et al. (2008), Assessment of the quality of the Version 1.07 temperature-versus-pressure profiles of the middle atmosphere from TIMED/SABER,

[1] The new Horizontal Wind Model (HWM07) provides a statistical representation of the horizontal wind fields of the Earth's atmosphere from the ground to the exosphere (0-500 km). It represents over 50 years of satellite, rocket, and ground-based wind measurements via a compact Fortran 90 subroutine. The computer model is a function of geographic location, altitude, day of the year, solar local time, and geomagnetic activity. It includes representations of the zonal mean circulation, stationary planetary waves, migrating tides, and the seasonal modulation thereof. HWM07 is composed of two components, a quiet time component for the background state described in this paper and a geomagnetic storm time component (DWM07) described in a companion paper.

[1] Gravity waves in the mesopause region (80-105 km) may induce perturbations in OH Meinal Band emissions at $87 km. These perturbations can be observed by ground-based OH airglow imagers. In this paper, we present observations of concentric gravity waves (CGW) by the all-sky OH imager at Yucca Ridge Field Station (40.7°N, 104.9°W) near Fort Collins, Colorado. We find that expanding rings of concentric gravity waves were observed on 9 out of 723 clear nights from 2003 to 2008. In particular, on 11 May 2004, concentric rings were observed for $1.5 h, with nearly perfect circular rings entirely in the field of view during the first 30 min. The centers of the concentric rings occurred at the geographic locations of two strong convective plumes which were active in the troposphere $1 h earlier. We measured the horizontal wavelengths and periods of these gravity waves as functions of both radius and time. These results agreed reasonably well with the internal Boussinesq gravity wave dispersion relation with an assumed zero background wind. Similarly, for the other 8 cases, strong convective plumes occurred prior to the CGW observations near the apparent center of each of the arcs or rings. For the 7 out of the 9 cases, radiosonde data were available up to z = 30-35 km. These data showed that the wind speeds from the tropopause to $30-35 km were smaller than $20-30 m/s. Because 8 of the 9 cases occurred when the total horizontal mean winds were weak and because the horizontal winds below $87 km were less than $20 m/s on 11 May 2004 (according to radiosonde and TIME-GCM model data), we postulate that weak background horizontal winds are likely a necessary condition for gravity waves excited from convective overshooting to be observed as concentric arcs or rings in the OH layer.

[1] Imaging measurements of a bright wave event in the nighttime mesosphere were made on 14 November 1999 at two sites separated by over 500 km in the southwestern United States. The event was characterized by a sharp onset of a series of extensive wavefronts that propagated across the entire sky. The waves were easily visible to the naked eye, and the entire event was observed for at least 5 1 2 hours. The event was observed using three wide-angle imaging systems located at the Boston University field station at McDonald Observatory (MDO), Fort Davis, Texas, and the Starfire Optical Range (SOR), Albuquerque, New Mexico. The spaced imaging measurements provided a unique opportunity to estimate the physical extent and time history of the disturbance. Simultaneous radar neutral wind measurements in the 82 to 98 km altitude region were also made at the SOR which indicated that a strong vertical wind shear of 19.5 ms À1 km À1 occurred between 80 and 95 km just prior to the appearance of the disturbance. Simultaneous lidar temperature and density measurements made at Fort Collins, Colorado, $1100 km north of MDO, show the presence of a large ($50 K) temperature inversion layer at the time of the wave event. The observations indicated that the event was most probably due to an undular mesospheric bore, a relatively uncommon disturbance which has only recently been reported [Taylor et al., 1995a]. Evidence is also shown to suggest that a large east-west tropospheric frontal system lying over the northern United States was the origin of the disturbance.

[1] Using a convective plume model and a ray trace model, we investigate the effects of winds on concentric rings of gravity waves (GWs) excited from a convective plume on 11 May 2004, near Fort Collins, Colorado. We find that winds can shift the apparent center of the concentric rings at z = 87 km from the plume location. We also find that critical level filtering (for GWs with small phase speeds propagating in the same direction as the wind) and wave reflection (for high-frequency GWs with small horizontal wavelengths propagating in the opposite direction to the wind) prevent many GWs from reaching the OH airglow layer. Additionally, we find that strong winds disrupt the concentric ring patterns, causing distorted ''squashed'' ring and arc-like patterns instead. Using a zero wind profile and a representative April mean zonal wind profile, we compare our model results with observations of concentric rings at the Yucca Ridge Field Station (40.7°N, 104.9°W). We find that the model horizontal wavelengths and periods agree reasonably well with the observed data. We also compare the model temperature perturbations with the temperature perturbations calculated from the intensity perturbations. Because the observations show less critical level filtering than from the April wind profile and more critical level filtering than from the zero wind profile, we conclude that the winds on 11 May were likely somewhat smaller than the April zonal wind profile assumed here.