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The vertical component of the geostrophic wind
Author(s) -
Egger Joseph,
Hoinka KlausPeter
Publication year - 2017
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.3044
Subject(s) - geostrophic wind , stratosphere , troposphere , northern hemisphere , forcing (mathematics) , geostrophic current , thermal wind , southern hemisphere , component (thermodynamics) , atmospheric sciences , meteorology , climatology , geology , environmental science , physics , wind speed , wind profile power law , thermodynamics
Motion in planetary geostrophic equations (PGEs) is represented by the three‐dimensional geostrophic wind ( u g , v g , w g ) where u g and v g are the standard horizontal components while the vertical component w g can be derived, for example, from the Richardson equation. However, this vertical component appears not to have been evaluated as yet on the basis of data nor compared to the actual vertical component w . Part of this missing information is provided here by an evaluation of w g from observations and by analyzing the role of w g in linear versions of PGEs. The time mean fieldsw ̂gin the Northern Hemisphere as well as the standard deviationsσw gare compared to the correponding fields of w . It is found thatw ̂gcomes reasonably close tow ̂ in the troposphere but deviates widely in the stratosphere whileσw gis smaller than σ w in the troposphere but not in the stratosphere. Linear wave motion is discussed and the linear steady‐state response to the forcing by heat sources and mountains is explored to explain these results.