GSWM-98: Results for migrating solar tides

We report on new global-scale wave model (GSWM) predictions for the migrati ng solar tide in the troposphere, stratosphere, mesosphere and lower thermo sphere. The model revision, hereafter GSWM-98, includes an updated gravity wave (GW) stress parameterization and modifications to the background atmos phere based on 6-year monthly averaged Upper Atmosphere Research Satellite (UARS) climatologies. UARS Halogen Occultation Experiment and Microwave Lim b Sounder ozone data are used to define the strato-mesospheric tidal source , while GSWM-98 background winds are based on UARS High Resolution Doppler Interferometer (HRDI) zonal mean zonal wind data. We quantify and interpret differences between previous diurnal and semidiurnal predictions, hereafte r GSWM-95, and GSWM-98 results. The revised GW stress parameterization acco unts for the most profound changes and leads to seasonal variability predic tions that are consistent with diurnal amplitudes observed in the upper mes osphere and lower thermosphere. Unresolved differences between HRDI and oth er wind climatologies significantly affect MLT tidal predictions.