Ch 19: Air Pressure & Wind

19.1

AIR PRESSURE= ______

______

  • ______in all directions
  • measured by a ______, units are ______
  • at ______, the air pressure is______
  • ______as you ______altitude
  • change in mercury level of a barometer =

-______

Wind

  • Wind is the result of ______differences in air pressure
  • Air moves from areas of ______pressure to ______pressure
  • Causing ______
  • These different areas of high & low pressure are caused by:
  • ______heating ( ______) of the Earth’s surface.
  • Wind speed is measured by an ______

Wind direction is measured by a ______

WIND DIRECTION IS CONTROLLED

BY ______THINGS:

______

______

______

  1. Pressure Differences
  • The ______the difference in air pressure between 2 regions, the ______the______
  • Specific weather maps indicate pressure differences across a region
  • ______
  • ______are lines that connect places of ______air pressure
  • ______spaced isobars indicate ______wind speeds
  • ______spaced isobars indicate ______wind speeds

  1. Coriolis Effect
  • describes how Earth’s ______affects ______
  • All free-moving objects are deflected to the ______of their path of motion in the ______hemisphere and to the ______in the ______hemisphere
  • affects only wind______
  • the ______the wind speed, the ______the deflection
  1. Friction
  • as air travels over ______terrain, the wind ______
  • changes wind ______
  • only important within a few kilometers of the______
  • High above friction zone = ______
  • Fast moving streams of air that travel between ______
  • Flow ______in ______

19.2

PRESSURE CENTERS

  • Most weather predictions are based on locations of ______air pressure zones

LOW

  • Low Pressure Zones or ______= ______conditions and ______
  • Pressure______toward the center of a ______pressure zone
  • Wind blows ______and ______around a low
  • - Because wind blows______, air must______to make room for incoming wind
  • ______

HIGH

  • High Pressure Zone or ______= ______skies and ______weather
  • Pressures ______toward the center
  • Winds blow______and ______from a high pressure center
  • Air ______in a high pressure zone
  • ______

19.3

  • Because more ______is received at the equator than at the poles, global wind patterns act to ______on Earth = warm air blows toward high latitudes and cool air flows toward equator
  • ______air blows toward______latitudes and ______air flows toward ______
  • Because the Earth______, above system is more complex
  • =______major wind cells in ______hemisphere

4 Major Wind Cells

-______

-______

-______

-______

EQUATORIAL LOW- air is ______at equator, it ______(producing abundant______) until it reaches the______, then air is ______toward the ______

SUBTROPICAL HIGH–the air that was ______at the______descends at ______latitude (subtropics), the ______air ______(at altitude)& ______

-creating most of the world’s ______

- The wind traveling toward the ______generate the ______of the middle latitudes (Our wind in Indiana almost always blows from ______because of this wind pattern)

  • POLAR HIGH90°= cold polar air sinks and flows along the surface toward ______latitude (Subpolar Low), and is again______
  • - creates the______, that bring ______polar air to ______
  • SUBPOLAR LOW 60

-60latitude is ______area because of ______air & the collision of ______(prevailing westerlies) and ______air masses (polar easterlies) creating an area known as the ______

LOCAL WINDS

Two types of ______:

______

______

Local Wind Patterns

  • ______are caused either by topographic effects or by variations in surface composition –______in the immediate area
  • ______BREEZE – develop shortly before ______& reach greatest intensity during ______
  • Form due to ______air rising over land (lower pressure) causing ______air over the water (higher pressure) to move in ______
  • Results in ______temperature on ______
  • ______BREEZE –develop in the evening
  • Form due to land cooling off ______than water.
  • Cool air over the land sinks (higher pressure) causing air to flow ______warmer wafer (lower pressure)
  • Can occur near ______or along the shores of large lakes, such as the ______

______breezes –similar to land & sea breezes but occur in ______regions

During the ______–air along the ______of the mountain is heated ______intensely than the ______

Causing warmer air on slopes to ______creating ______

Monsoon

Continents break up ocean surface, so global wind belts are ______continuous = ______temperature differences

  • Large continents like Asia get very cold during winter and create a ______pressure zone = air flow goes from ______toward______

Winter is extremely dry and cold ______

During summer Asia gets very hot, creates a ______pressure zone = air moves from ______toward ______

This complete seasonal wind reversal is called a ______

summer brings ______and ______weather from Indian Ocean

Winter is extremely ______and ______

______= unusually ______ocean ______(particularly the central and eastern Pacific Ocean) that creates ______weather patterns

- ______of normally ______currents & their ______

- causes very ______winters in ______Coast & very ______winters in ______

& ______

______= opposite of El Nino

- occurs when surface ocean temperatures are significantly ______than average, creates ______weather patterns

- Very ______winters to Pacific Northwest & Great Plains, ______winters for rest of US

- Increases ______frequency