Assessing How the Loss of Middle Atmospheric Profile Observations Impacts the Quality of High Altitude Meteorological Analyses

We will present results from the high-altitude version of the Navy Global Environmental Model (NAVGEM-HA) highlighting how the availability of satellite-based observations from the Aura Microwave Limb Sounder and TIMED SABER instruments throughout the stratosphere, mesosphere, and lower thermosphere impacts the performance of this coupled forecast/analysis system. As we will show, these high-altitude analyses are important for providing accurate initial conditions for whole-atmosphere forecast systems currently being developed for space weather applications. In addition, these analyses also provide key insight into the physical mechanisms coupling the lower and upper atmosphere through upward propagating waves over a wide range of spatial and temporal scales. As current middle atmospheric observing missions reach the end of their lifetime with no planned replacements, the potential loss of these observations could have a negative impact on our ability to provide accurate atmospheric state specification between 50-100 km altitude, affecting both operational forecasting and research efforts alike. In this study, NAVGEM-HA analyses with and without MLS and SABER middle atmospheric observations are used to diagnose the spatial and temporal evolution of winds, temperature, and constituents. These results are compared with independent observations to validate the global NAVGEM-HA analyses and demonstrate the sensitivity of the results to the availability of middle atmospheric observations.