Intercomparison of middle atmospheric meteorological analyses for the Northern Hemisphere winter 2009–2010

Abstract

Abstract. Detailed meteorological analyses based on observations extending through the middle atmosphere (∼ 15 to 100 km altitude) can provide key information to whole atmosphere modeling systems regarding the physical mechanisms linking day-to-day changes in ionospheric electron density to meteorological variability near the Earth's surface. However, the extent to which independent middle atmosphere analyses differ in their representation of wave-induced coupling to the ionosphere is unclear. To begin to address this issue, we present the first intercomparison among four such analyses, JAGUAR-DAS, MERRA-2, NAVGEM-HA, and WACCMX+DART, focusing on the Northern Hemisphere (NH) 2009–2010 winter, which includes a major sudden stratospheric warming (SSW). This intercomparison examines the altitude, latitude, and time dependences of zonal mean zonal winds and temperatures among these four analyses over the 1 December 2009 to 31 March 2010 period, as well as latitude and altitude dependences of monthly mean amplitudes of the diurnal and semidiurnal migrating solar tides, the eastward-propagating diurnal zonal wave number 3 nonmigrating tide, and traveling planetary waves associated with the quasi-5 d and quasi-2 d Rossby modes. Our results show generally good agreement among the four analyses up to the stratopause (∼ 50 km altitude). Large discrepancies begin to emerge in the mesosphere and lower thermosphere owing to (1) differences in the types of satellite data assimilated by each system and (2) differences in the details of the global atmospheric models used by each analysis system. The results of this intercomparison provide initial estimates of uncertainty in analyses commonly used to constrain middle atmospheric meteorological variability in whole atmosphere model simulations.

Improving the Thermosphere Ionosphere in a Whole Atmosphere Model by Assimilating GOLD Disk Temperatures

“…As full disk images are available at 30 min intervals during sunlit hours, a 1 hr interval will have sufficient data in the thermosphere. Also, the lower atmosphere analysis states in WACCMX + DART agree well with other lower atmospheric assimilations, for example, MERRA2 (McCormack et al., 2021).…”

Impact of Strong and Weak Stratospheric Polar Vortices on the Mesosphere and Lower Thermosphere

“…This is especially apparent for the SW2, which shows a clear linear relationship with the NAM. Although averaging over multiple events should reduce the uncertainty in the results, it is important to recognize that the results of the present study are based on SD‐WACCM‐X simulations, and there are known uncertainties in the capabilities of whole atmosphere models to reproduce short‐term variations in the MLT (McCormack et al., 2021; Pedatella et al., 2014). The results of the present study should be considered in the context of these uncertainties, and may differ from what occurs in the real atmosphere.…”

Mesosphere and Lower Thermosphere Winds and Tidal Variations During the 2019 Antarctic Sudden Stratospheric Warming

“…NAVGEM‐HA is an extension of the Navy operational weather forecast system (Hogan et al., 2014) up to the level at $$6\times {10}^{-5}$$ hPa (∼116 km altitude) and the vertical spacing is ∼2 km in the stratosphere and the mesosphere (McCormack et al., 2017, 2021). The top levels of the system at above ∼100 km altitude are specified with strong diffusion in order to reduce the wave reflection.…”

“…These observations have continuous temporal sampling, but their spatial coverage is limited to only certain geographic locations (e.g., Stober, Janches, et al., 2020; Stober, Baumgarten, et al., 2020). Global winds have been simulated using general circulation models, but the modeled winds exhibit substantial discrepancies among different models (e.g., McCormack et al., 2021; Pedatella et al., 2014). Parameterizations of gravity waves in whole atmosphere models are normally not sufficient (Garcia et al., 2017), and simulations of the breaking of very strong mountain waves over the Southern Andes and the Antarctic Peninsula are not adequate (e.g., Becker & Vadas, 2018).…”

“…To address this need for improved description of global MLT dynamics, a high‐altitude version of the Navy Global Environmental Model (or NAVGEM‐HA) has been developed for MLT research (Eckermann et al., 2018; Hoppel et al., 2013; McCormack et al., 2017, 2021). NAVGEM‐HA is a numerical weather prediction system that combines a global spectral forecast model with an advanced data assimilation system to produce global synoptic meteorological products extending from the surface to approximately 100 km altitude.…”