[1] Since February 2002, the SABER (sounding of the atmosphere using broadband emission radiometry) satellite instrument has measured temperatures throughout the entire middle atmosphere. Employing the same techniques as previously used for CRISTA (cryogenic infrared spectrometers and telescopes for the atmosphere), we deduce from SABER V1.06 data 5 years of gravity wave (GW) temperature variances from altitudes of 20 to 100 km. A typical annual cycle is presented by calculating averages for the individual calendar months. Findings are consistent with previous results from various satellite missions. Based on zonal mean, SABER data for July and zonal mean GW momentum flux from CRISTA, a homogeneous and isotropic launch distribution for the GROGRAT (gravity wave regional or global ray tracer) is tuned. The launch distribution contains different phase speed mesoscale waves, some of very high-phase speed and extremely low amplitudes, as well as waves with horizontal wavelengths of several thousand kilometers. Global maps for different seasons and altitudes, as well as time series of zonal mean GW squared amplitudes based on this launch distribution, match the observations well. Based on this realistic observation-tuned model run, we calculate quantities that cannot be measured directly and are speculated to be major sources of uncertainty in current GW parameterization schemes. Two examples presented in this paper are the average cross-latitude propagation of GWs and the relative acceleration contributions provided by saturation and dissipation, on the one hand, and the horizontal refraction of GWs by horizontal gradients of the mean flow, on the other hand.

Abstract. We present a new algorithm for the retrieval of kinetic temperature in the terrestrial mesosphere and lower thermosphere from measurements of CO2 15/•m earth limb emission. Non-local-thermodynamicequilibrium (non-LTE) processes are rigorously included in the new algorithm, necessitated by the prospect of satellite-based limb radiance measurements to be made from the TIMED/SABER platform in the near future between 15 km and 120 km tangent altitude. The algorithm requires 20 seconds to retrieve temperature to better than 3 K accuracy on a desktop computer, easily enabling its use in operational processing of satellite data. We conclude this letter with a study of the sensitivity of the retrieved temperatures to parameters used in the non-LTE models, including sensitivity to the rate constant for physical quenching of CO2 bending mode vibrations by atomic oxygen.

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on the Thermosphere‐Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite observed the infrared radiative response of the thermosphere to the solar storm events of April 2002. Large radiance enhancements were observed at 5.3 μm, which are due to emission from the vibration‐rotation bands of nitric oxide (NO). The emission by NO is indicative of the conversion of solar energy to infrared radiation within the atmosphere and represents a “natural thermostat” by which heat and energy are efficiently lost from the thermosphere to space and to the lower atmosphere. We describe the SABER observations at 5.3 μm and their interpretation in terms of energy loss. The infrared enhancements remain only for a few days, indicating that such perturbations to the thermospheric state, while dramatic, are short‐lived.

Mersey, England, taken from the air. The front of the bore (which is moving upward in the figure and opposite the direction of normal river flow) is followed by a series of waves. There is a striking resemblance to the airglow images in Figure 1. This suggests the spectacular event was caused by an internal undular bore in the mesosphere. 6295

[1] The dramatic solar storm events of April 2002 deposited a large amount of energy into the Earth's upper atmosphere, substantially altering the thermal structure, the chemical composition, the dynamics, and the radiative environment. We examine the flow of energy within the thermosphere during this storm period from the perspective of infrared radiation transport and heat conduction. Observations from the SABER instrument on the TIMED satellite are coupled with computations based on the ASPEN thermospheric general circulation model to assess the energy flow. The dominant radiative response is associated with dramatically enhanced infrared emission from nitric oxide at 5.3 mm from which a total of $7.7 Â 10 23 ergs of energy are radiated during the storm. Energy loss rates due to NO emission exceed 2200 Kelvin per day. In contrast, energy loss from carbon dioxide emission at 15 mm is only $2.3% that of nitric oxide. Atomic oxygen emission at 63 mm is essentially constant during the storm. Energy loss from molecular heat conduction may be as large as 3.8% of the NO emission. These results confirm the ''natural thermostat'' effect of nitric oxide emission as the primary mechanism by which storm energy is lost from the thermosphere below 210 km.