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
o Air moves from areas of ____________ pressure to _____________
pressure
o Causing ________________
 These different areas of high & low pressure are caused by:
o _________________ 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
o _____________________________________
 ______________________are lines that connect places of
_______________ air pressure
 ____________spaced isobars indicate ____________
wind speeds
 ____________spaced isobars indicate ___________wind speeds
2. 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
3. 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
o - 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
o ____________________________
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
o ___________air blows toward_______________ latitudes and
___________ air flows toward ____________________
o 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 HIGH 90°= cold polar air sinks and flows along the surface toward
______________ latitude (Subpolar Low), and is
again______________________
o - 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