Unit 5: Weather (pgs. 340-341)

• A weather factor is a condition of the atmosphere that influences or controls other elements of weather.

• Meteorologists are the scientists who track the factors that make up weather.

• Technologies used to track weather include:• weather balloons, Doppler Radar, weather satellites, and

other tools that we will explore in today’s lesson (see Weather Packet).

Weather Factor is a measure of… tool used to measure

Temperature

Precipitation

Wind Speed

Humidity

Air Pressure

Rain Gauge (inches)

ThermometerF or C)

Anemometer(Direction and mph)

Barometer(inches)

Hygrometer (percent)

Rain, sleet, snow, and hail

The average kinetic energy of particles.

The measure of the air with respect to the surface of the Earth

The amount of water vapor in the air

The force with which air particlespush on matter

Temperature and Air Masses (pgs 336-337)

• The angle at which the Sun hits the Earth affects the temperatures on Earth:• Areas that receive direct sunlight (like the equator) have higher

temperatures.• Areas that receive indirect sunlight (like the poles) have lower

temperatures.

• An air mass is a large body of air that has a similar temperature and humidity throughout.• An air mass gets its temperature and moisture characteristics from

the area of Earth’s surface over which it forms. • Air masses of different temperatures do not mix easily, often

causing a front (where it can be stormy or cloudy).

Air Pressure pg. 328

• In areas of high pressure, the air molecules are cool and close together.• Air SINKS because it is

more dense. This creates good weather.

• In areas of low pressure, air molecules are far apart. • Air RISES because it

is less dense. This creates bad weather.

High Pressure

Air sinks: good weather

Air molecules at 38°F

Low PressureAir Rises: Forming clouds and precipitation.

Air molecules at 60°F

Weather Factor High or Low? Resulting Weather Conditions

High

Low

High

Low

High

Low

Temperature If the temperature is high, the result is warm or hot weather.

If the temperature is low, the result is cool or cold weather.

Air Pressure If the air pressure is high, the result is good weather.

If the air pressure is low, the result is bad weather.

Humidity If the humidity is high, precipitation is likely.

If the humidity is low, precipitation is not likely.

Weather Factor High or Low? Resulting Weather Conditions

High

Low

High

Low

High

Low

Temperature If the temperature is high, the result is warm or hot weather.

Air Pressure If the air pressure is high, the result is good weather.

Humidity If the humidity is high, precipitation is likely.

Global and Local Winds (pgs. 330-331) • Wind is moving air caused by differences in air pressure.• Warm, less dense, air rises while cooler, more dense, air sinks. This constant

rotation causes wind! (Vocab. shout out: it’s a convection current!) .

• The greater the difference in air pressure between two air masses, the stronger the wind will be.

• Local winds are caused by unequal heating of a large body of water and the land near it. • In New Jersey, the jet stream can bring cold artic air from the poles or hot air

from the equator

• Global winds are created when warm air from the equator rises and cool air from the poles sink.

Air Pressure pg. 328• Air pressure is greatest at the

Earth’s surface and decreases as you move away from the Earth. • The Earth’s gravitational pull

becomes weaker as you leave the Earth.

• As temperature increases, air pressure decreases.• The air molecules are moving

more quickly because they have more energy.

High Pressure

Low Pressure

Air sinks: good weather

Air Rises: Forming clouds and precipitation.

Air molecules at 38°F

Air molecules at 60°F

• In areas of high pressure, the air molecules are cool and close together.• Air SINKS because it

is more dense. This creates good weather.

• In areas of low pressure, air molecules are far apart. • Air RISES because it

is less dense. This creates bad weather.

Major Global Winds and Surface Currents • Global winds create surface currents: • Surface currents form as wind transfers energy to the ocean waters.

• Global winds push the temperature of the surface currents onto the land affecting weather.

• A gyre is a large system of rotating ocean currents.

• Winds and surface currents act in a curved line because of the Coriolis Effect.

Climate (pg 342-343)• Climate is a pattern of weather that occurs over a long period of time.

• Climate is usually described by average temperatures and average precipitation.

• The climate in an area can be affected by– amount of sunlight– large bodies of water and ocean currents– pollution

Climate Zones• A climatograph is used to show the average precipitation and the

average temperature of a region.

• Climate zones are divisions of the Earth's climates into different zones according to average temperatures and average rainfall.

• The three major climate zones on the Earth are the polar, temperate, and tropical zones.