Measurement of gravity wave activity

Measurement of gravity wave activity in terms of standard deviation of temperature perturbations at (upper left) 78, (upper right) 1.1, (lower left) 1.1×10E−4 and (lower right )1.1×10E−7 hPa, averaged over four UT times (0, 6, 12, and 18 hours) for January. The contour lines are stream functions calculated from the horizontal winds. Contour lines with lighter shades have larger values. Atmosphere flow is tangent to the streamlines and toward the right of the down-gradient direction of the stream functions.

Journal of Advances in Modeling Earth Systems:  Small scale waves can be excited from daily weather near the Earth surface. These waves, termed gravity waves, can propagate upward and are thought to influence the middle and upper atmospheric regions. Such effects, however, are difficult to directly quantify by observations and numerical modeling due to their small scales and global presence. To address this challenge, we have developed a high-resolution whole atmosphere model (WACCM-X), which extends from the Earth surface to the upper thermosphere, that can partially resolve the small scale waves. The simulated waves are compared with available observations to verify the model results and to examine how these waves are distributed geographically and over altitudes. The simulations show that wave signatures can be clearly identified in the neutral and the ionized atmosphere, which can have important implications for space weather.