CHAPTER 6 AirSea Interaction

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CHAPTER 6Air-Sea Interaction
Fig. 6.11
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Overview

• Atmosphere and ocean one interdependent system
• Solar energy creates winds
• Winds drive surface ocean currents and waves
• Examples of interactions
• El Niño-Southern Oscillation
• Greenhouse effect

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Seasons

• Earths axis of rotation tilted with respect to
  ecliptic
• Tilt responsible for seasons
• Vernal (spring) equinox
• Summer solstice
• Autumnal equinox
• Winter solstice
• Seasonal changes and day/night cause unequal
  solar heating of Earths surface (longer days,
  more intense solar radiation during summer)

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Seasons
Fig. 6-1
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Uneven solar heating

• Angle of incidence of solar rays per area
• Equatorial regions more heat
• Polar regions less heat
• Thickness of atmosphere
• Albedo
• Day/night
• Seasons

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Uneven solar heating on Earth

• Solar energy in high latitudes
• Has a larger footprint
• Is reflected to a greater extent
• Passes through more atmosphere
• Is less than that received in low latitudes

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Oceanic heat flow

• A net heat gain is experienced in low latitudes
• A net heat loss is experienced in high latitudes
• Heat gain and loss are balanced by oceanic and
  atmospheric circulation

Figure 6-3
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Physical properties of the atmosphere
Composition (dry air)
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Physical properties of atmosphere

• Atmosphere mostly nitrogen (N2) and oxygen (O2)
• Temperature profile of lower atmosphere
• Troposphere temperature cools with increasing
  altitude

Fig. 6.4
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Physical properties of atmosphere

• Warm air, less dense (rises)
• Cool air, more dense (sinks)
• Moist air, less dense (rises)
• Dry air, more dense (sinks)

Fig. 6.5
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Physical properties of the atmosphere Water vapor

• Cool air cannot hold much water vapor, so is
  typically dry
• Warm air can hold more water vapor, so is
  typically moist
• Water vapor decreases the density of air

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Movements in atmosphere
Fig. 6.6

• Air (wind) always moves from regions of high
  pressure to low
• Cool dense air, higher surface pressure
• Warm less dense air, lower surface pressure

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Oceanic heat flow

• A net heat gain is experienced in low latitudes
• A net heat loss is experienced in high latitudes
• Heat gain and loss are balanced by oceanic and
  atmospheric circulation

Figure 6-3
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Movements in air
Non-rotating Earth

• Air (wind) always moves from regions of high
  pressure to low
• Convection or circulation cell

Fig. 6.7