Group seminar on 06. April, 14:15 CET

Wavenumber and frequency filtering of the equatorial Kelvin wave

This seminar will discuss properties of the linear Kelvin waves in the troposphere and stratosphere using 40 years of ERA5 reanalyses. Results of the wavenumber filtering (WF) and wavenumber-frequency filtering (WFF) will be compared. WF is performed using classical wave theory independent of time dimension whereas WFF applies the Wheeler-Kiladis (1999) method. The complex time series from WF is analyzed in the zonal and vertical wavenumber domains in terms of frequencies from linear wave theory. The comparison with WFF of the Kelvin wave zonal winds at different levels in the troposphere and stratosphere shows that power spectra from WFF in the troposphere are largely defined by wave phases.