Pressure and Wind ©Mark Place, 2007-2008 www.LearnEarthScience.com

What instrument is used to measure: wind speed air pressure Measured in Knots Measured in millibars or inches of mercury anemometer barometer [ORIGIN from Greek anemos ‘wind’] [ORIGIN from Greek baros ‘weight’]

How are winds named? The direction from which they come Wind Vane From the EAST Which way is the wind moving??

What causes wind? differences in pressure

Which pressure gradient would result in greater wind velocity? S K E T C H

measurements using the chart Convert the following measurements using the chart on page 13 of the ESRTs. 29.74 997 30.18 994

Wind blows from areas of to areas of high pressure low pressure

Draw the relationship between air pressure and air density.

Warm air is LESS dense than cold air Temp. and Density Warm air is LESS dense than cold air Density Temperature

This is because the air is Therefore, clouds CANNOT form. In a high pressure area, air will (rise, sink) because the air is (less, more) dense. This is because the air is (cold, warm) and (rises, sinks). Therefore, clouds CANNOT form.

This is because the air is In a low pressure area, air will (rise, sink) because the air is (less, more) dense. This is because the air is (cold, warm) and (rises, sinks). Therefore, clouds are LIKELY to form.

CYCLONE ANTICYCLONE Correctly draw the direction of wind flow around both a high and a low pressure area in the NORTHERN HEMISPHERE. **Get the arrows correct** CYCLONE ANTICYCLONE

counterclockwise wind direction low pressure high pressure warm or cold air air rising or sinking clouds or no clouds clockwise or counterclockwise wind direction winds toward or away from the center warm cold rising sinking clouds no clouds counter clockwise clockwise toward away

On the diagrams below, label which one represents a land breeze and which represents a sea breeze. Correctly label on each diagram where the high and low pressure areas would be found.

Sea Breeze (daytime) H L On the diagrams below, label which one represents a land breeze and which represents a sea breeze. Correctly label on each diagram where the high and low pressure areas would be found. Sea Breeze (daytime) H L

Land Breeze (night time) L H On the diagrams below, label which one represents a land breeze and which represents a sea breeze. Correctly label on each diagram where the high and low pressure areas would be found. Land Breeze (night time) L H

What’s the relationship between wind and waves? direct (the stronger the wind, the bigger the waves)

45°N 45°S 75°N 20°N southwest northwest northeast northeast Using the chart on page 14, state the prevailing wind direction for each latitude below: 45°N 45°S 75°N 20°N southwest northwest northeast northeast

Is air rising or sinking at the equator?

Is air rising or sinking at 30°N?