The globally integrated subseasonal variability associated with the two main atmospheric circulation regimes, the balanced (or Rossby) and unbalanced (or inertia–gravity) regimes, was evaluated for the four reanalysis datasets: ERA-Interim, JRA-55, MERRA, and ERA5. The results quantify amplitudes and trends in midlatitude traveling and quasi-stationary Rossby wave patterns as well as in the equatorial wave activity across scales. The main finding is a statistically significant reduction of subseasonal variability is found in Rossby waves with zonal wavenumber k = 6-8 along with an increase in variability in wavenumbers k = 3–5 in the summer seasons of both hemispheres.
COBISS.SI-ID: 26783747
A new measure of subseasonal variability is introduced that provides a scale-dependent estimation of vertically and meridionally integrated atmospheric variability Applied to the ERA-Interim data, the new measure shows that subseasonal variability decreases for larger zonal wave numbers. Time series of globally integrated variability anomalies in ERA- Interim show an increase in variability after year 2000.
COBISS.SI-ID: 374697