Table 2: Periods 𝑇 𝑑 𝑟 and growth rates 𝜔 𝑑 𝑖 of selected modes for the 1949–68 NCEP/NCAR basic state with standard parameterizations ( 𝐾 𝑑 = 2 . 3 3 8 × 1 0 1 6 m4 s−1, 𝑄 𝑑 𝐹 = 1 5 0 0 K, 𝐶 𝑑 𝐹 = 5 × 1 0 4 K m−1), their mode number, and class of mode. Also shown are the largest pattern correlations 𝐴 𝑐 between a given mode and the modes for the 1997–2006 NCEP/NCAR basic state with standard parameterizations and the 1997–2006 mode for which the pattern correlation is largest as well as the change in the growth rate Δ 𝜔 𝑑 𝑖 .

Class Mode 𝑇 𝑑 𝑟 𝜔 𝑑 𝑖 𝑇 𝑑 𝑟 𝜔 𝑑 𝑖 𝐴 𝑐 Mode Δ 𝜔 𝑑 𝑖
1949–68(days)(day−1)(days)(day−1)1997–2006

SH cyclogenesis11.200.42501.330.26630.896012−37.3%
ML blocking306.110.25666.270.20740.639926−19.2%
HL blocking87.400.34958.010.35000.76445+0.1%
HL blocking115.220.31844.990.30600.80286−3.9%
NWCB438.010.21007.970.30540.63747+45.4%
Antarctic613.080.362420.00.38100.90713+4.9%
Antarctic2652.10.2746 0.28500.647510+3.8%
ISO5759.00.144425.40.18860.574433+30.6%
African EW224.140.28813.860.30350.76388+5.3%