Ribera P. and Mann M.E., 2002. Interannual variability in the NCEP Reanalysis 1948-1999. Geophysical Research Letters, 29, 132-1-132-4.

reprint

QUASI-QUADRIENNIAL OSCILLATION

Spatial reconstructions of QQ oscillation for 1000 hPa (bottom) and 500 hPa (top) levels. Animation for a 5 degrees steps, from phase 0 to 355 (phase is indicated by small arrow to the left of QQ maps). Temperature anomalies are indicated by the asociated color scale. Geopotential height anomalies are indicated by (magenta) contours (solid line: positive anomalies, dashed line: negative anomalies, dotted line: zero contour, intervals shown indicate -12, -4, 0, 4, 12 m anomalies). QQ OSCILLATION: FOUR FIELDS

1000 hPa
500 hPa 
 

As animation but with wind arrows included. The intensity of the wind anomaly is proportional to the arrow lenght. Phases are: 0, 45, 90, 135 and 180.