TY - GEN A1 - Will, Andreas A1 - Harlander, Uwe A1 - Metz, Werner T1 - Climatological relevance of leading seasonal singular vectors. Part I: Energy, enstrophy and spatio – temporal variability T2 - Meteorologische Zeitschrift N2 - Fast growing atmospheric Rossby wave trains (RWT modes) are solutions of a Singular Vector (SV) analysis of a damped barotropic vorticity equation for northern winter basic flows. Using 40 DJF basic flows RWT modes are found over four regions of the globe only. Their propagation paths are remarkably constant for development times up to 96 h, but spread for longer times. The RWT mode with the largest 4 day growth rate develops over the North-Pacific (NPAC) region for each of the observed DJF basic flows considered. This mode is referred to as NPAC-mode. The eigenvalues, which are the 4 day kinetic energy growth factors of the NPAC mode, range from 10 to 24 for nearly all of the basic flows. In some exceptional years they are close to 30. The NPAC modes with moderate growth factors could be shown to be approximate solutions of the nonlinear model equation. Hereto a new formulation of the advection term provided by the energy-vortex theory was used. It appears that the constancy of propagation paths and the mode's shapes, the large growth factors and the validity of the linearization assumption up to development times of 96h make the NPAC mode a candidate to explain substantial parts of large scale interannual atmospheric variability in the North Pacific region. KW - Meteorology KW - Rossby Waves KW - Extreme Event KW - Teleconnection KW - PNA KW - Enstrophy KW - Energy KW - Energy Vorticity Theory Y1 - 2006 U6 - https://doi.org/10.1127/0941-2948/2006/0145 SN - 1610-1227 VL - 15 IS - 4 SP - 1 EP - 10 ER -