Contributions of Lower Atmospheric Drivers to the Semiannual Oscillation in Thermospheric Global Mass Density

McArthur Jones Jr1,2, John T Emmert3, Douglas Patrick Drob4 and David E Siskind1, (1)US Naval Research Laboratory, Space Science Division, Washington, DC, United States, (2)US Naval Research Laboratory, Space Science Divsion, Washington, DC, United States, (3)U.S. Naval Research Laboratory, Space Science Division, Washington, DC, United States, (4)Naval Research Lab, Space Science Division, Washington, United States