Angular Momentum Balance
and Winds
Tuesday, January 7, 2014
Earth’s prevailing winds
(Source: CLAUS, http://badc.nerc.ac.uk/data/claus/)
Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Earth’s prevailing winds
Easterlies
(Source: CLAUS, http://badc.nerc.ac.uk/data/claus/)
Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Earth’s prevailing winds
Westerlies
Easterlies
Westerlies
(Source: CLAUS, http://badc.nerc.ac.uk/data/claus/)
Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Earth’s surface winds
Speed
(Source: ERA40 reanalysis)
Tuesday, January 7, 2014
Earth’s surface winds
Westerlies
NE trades
SE trades
Westerlies
Speed
(Source: ERA40 reanalysis)
Tuesday, January 7, 2014
Earth’s rotation is important!
“The cause of the General Winds have not
Westerlies
been fully explained by any of those who
have
written on that Subject, for want of
NE
trades
more particularly and distinctly considering
SE
trades
the Share of the diurnal Motion of Earth
has in the production
of them.”
Westerlies
G. Hadley (1735)
Tuesday, January 7, 2014
Hadley’s view of winds and the general circulation
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Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Hadley’s view of winds and the general circulation
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Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Hadley’s view of winds and the general circulation
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Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Hadley’s view of winds and the general circulation
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Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Hadley’s view of winds and the general circulation
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)*+,(
Courtesy: Tapio Schneider
Tuesday, January 7, 2014
Observed annual general circulation
Hadley Cells
Ferrel Cells
Easterlies
Westerlies
Westerlies
(Data source: ERA40)
Tuesday, January 7, 2014
Hadley circulation confined to tropics
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Tuesday, January 7, 2014
Hadley circulation confined to tropics
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Extratropical macroturbulence transports angular
momentum into regions of wave generation
Tuesday, January 7, 2014
Eddy
angular
momentum
transport
Eddy angular momentum transport
Angular momentum flux convergence most important
in upper troposphere; mostly accomplished by eddies
(ERA-40 Atlas, http://www.ecmwf.int/research/era/ERA-40_Atlas/)
(Source: http://www.ecmwf.int/research/era/ERA-40_Atlas/)
Tuesday, January 7, 2014
Eddy
angular
momentum
transport
Eddy angular momentum transport
Angular
momentum
convergence
most
Angular
momentum
flux flux
convergence
mostisimportant
in the
upper
troposphere.by eddies
in upperimportant
troposphere;
mostly
accomplished
(ERA-40 Atlas, http://www.ecmwf.int/research/era/ERA-40_Atlas/)
(Source: http://www.ecmwf.int/research/era/ERA-40_Atlas/)
Tuesday, January 7, 2014