Chapter 8 - The Atmosphere in Motion: Air Pressure, Forces, and Winds

Index of Lecture Notes

• introduction - what generates wind?
• horizontal versus vertical pressure changes
• pressure defined (again)
• ideal gas law
• pressure changes due to changes in density
• pressure changes at the surface due to temperature changes in columns of air
• pressure changes aloft due to temperature changes in columns of air
  • the resultant air movement
• how to measure pressure- barometer
  • aneroid barometer
  • altimeter and barographs
• measuring pressure at the surface - mean sea level pressure chart
• error due to changing elevation
• reducing pressure to sea level
• representing pressure aloft - tropopause height variation with latitude
• pressure variation on a constant height surface
  • example of a 5 km MSL chart
• isobaric charts
  • example of a 500 mb chart
• approximate heights of the common isobaric charts
• troughs and ridges on isobaric charts
• relationship between ridges/troughs aloft and surface highs/lows
• what generates wind - Newton's Second Law
• forces defined
• the pressure gradient
  • large and small pressure gradients
• the pressure gradient force
  • pressure gradient force around lows and highs
  • example of determination of the pressure gradient force on a surface chart
  • pressure gradient force and winds aloft - N-S pressure gradient
• introduction to the coriolis force
• introduction to the coriolis force, cont
  • parcel aloft initially at rest
  • parcel position at a later time
  • parcel position at an even later time
  • final parcel position and movement due to balance of pressure gradient force and coriolis force
  • force balance and definition of geostrophic flow
• geostrophic winds - introduction
• strength of the geostrophic winds
• strength of the geostrophic winds, continued
• introduction to gradient flow
  • the centrifugal force
  • force balance with gradient flow
• effect of friction on winds
• difference in flow at surface and aloft
• frictional effect on winds near surface highs and lows
  • associated weather near highs and lows
• measuring winds
• wind direction
• Review Questions
• SAMPLE TEST QUESTIONS FOR CH 8
• CH 9 HOMEWORK:  NOTES | PROBLEMS