Horizontal Structure of 500 mb Height Fluctuations with Long, Intermediate and Short Time Scales

Abstract

Abstract Maps of standard deviations and one-point correlation maps based on twice-daily data subjected to a variety of temporal filters are presented, in order to document the horizontal structure of 500 mb height fluctuations with different time scales. The filters have been chosen to isolate fluctuations with long time scales (periods much longer than 30 days), intermediate time scales (10–30 day periods) and short time scales (2.5–6 day periods). The one-point correlation maps for long time scales resemble the teleconnection patterns described by Wallace and Cutzler. These patterns are strongly regionally dependent, with meridionally oriented dipole structures in the jet exit regions over the oceans, indicative of strong fluctuations in the zonal wind. For intermediate time scales, the dominant patterns consist of more zonally oriented wave trains which originate in the jet entrance regions and cross the jet streams as they curve southeastward into the tropics. Another important distinction between th...