Group seminar on 14. February, 14:15 CET

Initializing equatorial waves and its benefits on extra-tropical forecasts

Chen Wang

A significant amount of variability in the tropics has been associated with non-Rossby waves, i.e. the equatorial Kelvin, mixed Rossby-gravity and inertia-gravity waves. The existing data assimilation schemes account for these waves only in an implicit way such internal dynamics within the 4D-Var or regressions within EnKF methods. a multivariate data assimilation using wind and mass coupling of the non-Rossby equatorial waves may reduce tropical analysis uncertainties. The hypothesis is supported by projection of NWP tropical forecast errors in equatorial waves. Previous studies show its impact in a tropical channel model. Similar results will be presented from the TIGAR data assimilation model. Preliminary analyses on the improvements of forecasts, especially the improved extra-tropical forecasts from tropical observations, will also be discussed.