Long-term variability and tendencies in non-migrating diurnal tide from WACCM6 simulations during 1850-2014

This study reports the long-term variability and tendencies in important non-migrating (DE3, DW2, DW3) and stationary (DS0) diurnal tides using a three-member ensemble of historical simulations of National Center for Atmospheric Research Whole Atmospheric Community Climate Model latest version 6 for 1850-2014 (165 years). The climatological features of the tide in temperature (T), zonal wind (U) and meridional wind (V) are presented for equinoxes/solstices and winter/summer.

The response due to solar cycle (SC), quasi biennial oscillation at 10 hPa and 30 hPa, El Niño-Southern Oscillation (ENSO), ozone depleting substances (ODS), carbon dioxide (CO2), and stratospheric sulfate aerosol (volcanic eruptions) to change in tidal amplitudes with respect to 1850-1860 are analyzed using multiple linear regression. The annual mean amplitudes increase in the upper mesosphere and lowermost thermosphere (0.0001-0.01 hPa) in the three components predominantly due to increasing CO2 and the ODSs play secondary role.