ATMO 2301 Class #10: Monday, September 20, 2010 The B Climate Types The Oceans 1 Monday, September 20, 2010
Feb 05, 2016
ATMO 2301 Class #10: Monday, September 20, 2010
The B Climate TypesThe Oceans
1Monday, September 20, 2010
The B (dry) climate types
• Occupy more area than any other climate group—deficient in precipitation most of year
• Have potential evaporation and transpiration that exceed precipitation
• Generally occur in 2 contexts– Near the subtropical highs– On the leeward or downwind side of mountain
ranges
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B Climate Subgroups
• There are four: BWh, BWk, BSh, BSk– W is a true desert, extremely dry– S is semi-arid, or steppe
– h is a hot climate– K is a cold (in winter) climate
– Lubbock has a BSk climate
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Fig. 17-6, p. 477Monday, September 20, 2010 4
Fig. 17-7a, p. 478Monday, September 20, 2010 5
Fig. 17-7b, p. 479Monday, September 20, 2010 6
Table 17-1a, p. 480Monday, September 20, 2010 7
Fig. 17-2, p. 472Monday, September 20, 2010 8
Fig. 17-5, p. 476Monday, September 20, 2010 9
Fig. 17-12, p. 484Monday, September 20, 2010 10
Fig. 17-13, p. 484Monday, September 20, 2010 11
Fig. 17-15, p. 486Monday, September 20, 2010 12
Fig. 17-14, p. 485Monday, September 20, 2010 13
Fig. 17-16, p. 486Monday, September 20, 2010 14
More B Climate facts
• Subtropical deserts extend from roughly 20-30° latitude in large continental regions, often surrounded by mountains
• Xerophytes are plants capable of surviving long periods of drought—cacti, creosote bushes and short-lived plants
• Steppe has characteristic vegetation—short bunch grass, scattered low bushes, sagebrush
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Introduction to the oceans
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Interpreting heat fluxes for the oceans
• Positive ocean heat flux– Ocean gains energy– Ocean temperature < air temperature
• Negative ocean heat flux– Ocean loses energy– Ocean temperature > air temperature
• Fluxes are radiative, sensible and latent heating
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Fig. 8-1, p. 210
Advection of energy by ocean currents
• Advection helps balance the overall energy budget of the earth and atmosphere
• Chapter 2 included only the average for the whole globe
• There is an energy deficit at higher latitudes• There is an energy excess at lower latitudes
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Fig. 8-2, p. 211
Vertical structure of the oceans
• There are three layers of the ocean• Nearest the surface is the surface zone or
mixed layer of nearly constant temperature• Deepest is the deep zone of slowly decreasing
temperature approaching 0°C• Between the surface layer and the deep zone
is the thermocline, where temperature decreases downward rapidly from the surface layer
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Fig. 8-3, p. 212
Fig. 8-4, p. 213
Sea Surface Temperatures
• Are actually measured a few feet below the surface
• Are influenced by latitude and ocean currents• Cold ocean currents flow equatorward or in
the west to east direction in middle and high latitudes
• Warm ocean currents flow poleward or in the east/west directions in tropical latitudes
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Fig. 8-5, p. 213
Directions of ocean currents
• Ocean currents flow in gyres around the various ocean basins
• The gyres flow in an anti-cyclonic direction, clockwise in the Northern Hemisphere and counter-clockwise in the Southern Hemisphere
• The gyres form under the influence of the subtropical highs, the deflection of the Coriolis effect, surface friction, and the boundaries of land masses
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Fig. 8-6, p. 214
The oceans have motions similar to weather systems in the atmosphere
• Front-like features can develop at the boundaries of ocean currents
• Eddies can develop at the boundaries of ocean currents
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Fig. 8-7, p. 214
Fig. 8-8, p. 215
Fig. 8-9, p. 215
Fig. 8-10, p. 216
Fig. 8-11, p. 217
Fig. 8-12, p. 218
Fig. 8-13, p. 218
Fig. 8-14, p. 219
Table 8-1, p. 220
Fig. 8-15, p. 221
Fig. 8-16, p. 221
Fig. 8-17, p. 222