Ridge (meteorology)

A back or high-pressure wedge is a term used in meteorology and refers to a large-scale area high air pressure, which forms as a poleward vaulted wave crest in connection with the Polarfrontjetstream. It is usually filled with tropical warm air. In contrast to areas of high pressure ridges are not completely surrounded by low pressure and mostly pronounced at altitudes over 4,000 m.

About the back an intensive energy transport from higher to lower latitudes is performed. About the poleward advancing warm air, the isobaric surfaces bulge on and promote a meandering course ( Rossby waves ) of Polarfrontjetstreams. If the shaft vibrations well trained, there is flow divergences and convergences -. A high-pressure wedge caused the wave crest always divergent air flow because the jet stream then acts in the same direction with the Gradientkraft. Sinking air masses and on the ground then air flowing movement ( anticyclonic conditions ) are the result. At a back followed by a trough of low pressure, which is characterized by convergence, as the jet stream, against the Gradientkraft, so as a slightly upstream gradient wind flows.

Through the interplay of convergence and divergence of wave troughs of the jet stream and mountains can be high pressure and low pressure troughs wedges form and develop. The long waves as well as the back and troughs can be seen on the weather map clearly dam during the isobars. Back and troughs are particularly intense with a negative NAO index ( blocking meridional directed to weather conditions ).

A back controls the displacement of an anticyclone near the ground. The axis inclination plays a big role: With a vertical axis inclination, the high remains stationary. In an east-facing slopes with the height axis amplifies the high or it is shifting eastward. If the axis is inclined westward, the high is weakened or shifted to the west.

With progressive Labiliserung the frontal zone and a gradual transition from the meridional circulation (negative NAO index ) for Zonalzirkulation (positive NAO index ) of the jet stream, the poleward pre- initiated high-pressure wedge are cut off from the headwaters of the hot air through the jet stream ( cut-off effect). This now fully gravure Surrounded high pressure area can not be filled directly with tropical warm air, but can it as intermediate high yet the places through which it wedged between two low pressure systems or low pressure troughs pulls, bring friendly weather.

Swell

  • Back in the weather glossary of weather online
  • William Lauer, J. Bendix: climatology. 2nd ed Westermann, Braunschweig 2006, ISBN 3-14-160284-0.
  • Wolfgang Weischet, W. Finite: Introduction to the general climatology. 7th edition Borntraeger, Berlin / Stuttgart 2008, ISBN 3-44-307142-2.
  • Meteorological concept
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