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Perspicacious indicators of atmospheric blocking
Author(s) -
Schwierz C.,
CrociMaspoli M.,
Davies H. C.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl019341
Subject(s) - blocking (statistics) , tropopause , troposphere , northern hemisphere , climatology , environmental science , atmospheric circulation , anomaly (physics) , potential vorticity , atmospheric sciences , scale (ratio) , vorticity , meteorology , geology , vortex , geography , computer science , physics , computer network , condensed matter physics , cartography
A novel dynamically‐based approach is introduced to identify, describe and diagnose atmospheric blocking events. The approach is based upon the potential vorticity perspective and takes into account the three‐dimensional structure of the phenomenon. It is argued that the essence of a blocking anomaly is located in the upper troposphere, just below the tropopause. The associated novel blocking indicators are derived from two‐dimensional fields at 6‐hourly temporal resolution, and provide information on the spatial scale, shape, amplitude and movement of blocks. A northern hemisphere winter (DJF) climatology for the ERA15 period (1979–1993) is presented and comments are made on the relationship between the indicators and previous blocking indices.