The Storm Tracks in ERA
The Storm Track
Former Graduate Student of Leipzig Institute for Meteorology, University of Leipzig, Germany, PhD Candidate in GEOMAR, Kiel, Germany
Storm tracks are the atmospheric zones where extra-tropical cyclones grow and decay. A measure of strength and direction of the storm tracks can be quantified in a number of ways. One such way is track the lows as they move across the oceans and compile statistics about the tracks over a long period of time. Following figures are one of methods to indetify the storm tracks using transient poleward temperature flux and transient geopotential height covariance flux.
The 700mb transient poleward temperature flux from observations for 55 Northern Hemisphere winters (1958-2012). The measure reaches a maximum over the North Atlantic and North Pacific Oceans, the storm track regions where extra-tropical cyclones are most frequent and most intense.
Transient 250mb covariance of geopotential height flux for 55 Northern Hemisphere winters DJF (1958-2012), on a pressure level which is at a height of a few kilometres up into the atmosphere