ThursdayApril 19, 2012

(World Distribution of Temperature;

Measuring Atmospheric Pressure )

The Launch PadThursday, 4/19/12

This weather station model shows conditions for an area of the United States. Please provide the following

information for this area:wind directionwind speed

sky conditionstemperature

dew pointprecipitation?

barometric pressurerecent change in barometric

pressure

Assignment Currently Open

Summative or Formative Date Issued Date Due

Date Into Grade Speed

Last Day

WS – The Structure of the

AtmosphereF 4/4 4/10

Activity – Write Test Questions on Atmospheric

HeatingS 4/10 4/10

Quiz 26 S 4/13 4/13

Activity – Write Test Questions

on Cyclones and Anticyclones

S 4/17 4/17

AnnouncementsI will not be

available after school today.

Latest News

http://www.sciencedaily.com/releases/2012/03/120325173206.htm

Extreme Weather of Last Decade Part of Larger Pattern Linked to Global Warming

Click below for article:

World Distribution of Temperature Temperature maps help analyze temperature distribution over given

areas. Temperatures are adjusted to sea level to eliminate the variable of

altitude.January and July are used for analysis because they represent the

temperature extremes.

World Distribution of Temperature

On these maps, an

isotherm is a line

connecting places of

equal temperature.

World Distribution of Temperature

On a global scale, temperature

patterns emerge. The temperature

decreases poleward from the tropics.

Isotherms exhibit a latitudinal shift

with the seasons.The warmest and

coldest temperatures occur

over land.

World Distribution of Temperature

In the Southern Hemisphere, isotherms are straighter and

more stable. Isotherms show the annual temperature range of ocean

currents. Ranges are small near the

equator, and increase with an increase in latitude

Ranges are greatest over continental locations.

World Mean Sea-Level Temperatures in January

World Mean Sea-Level Temperatures in July

Atmospheric Pressure Atmospheric pressure is the

force exerted by the weight of the air above.

The weight of the air above at sea level is 14.7 pounds per

square inch.

This pressure decreases with increasing altitude.

A common measurement unit of atmospheric pressure is the

millibar (mb).

Standard sea level pressure is 1013.2 mb.

Atmospheric Pressure Another unit used in

atmospheric pressure measurement is inches of

mercury.

Standard sea level pressure is 29.92 inches of mercury.

The instrument used for measuring atmospheric

pressure is the barometer.

The mercury barometer was invented by Torricelli in 1643.

It uses a glass tube filled with mercury.

Atmospheric Pressure Another type of barometer is the aneroid barometer, meaning “without liquid.”

This type of barometer uses an expanding

chamber. Another pressure instrument is the barograph, which

continuously records the air pressure.

Barometric Pressure Equivalents

normal sea level pressure (at 0oC) = 760 mm Hg

760 mm Hg = 29.92 in. Hg = 1013.1 mb

1 in. Hg = 33.86 millibars (mb)