What are weather climate?

January 2013

Weather is what the air is like outside.

You might say it is too hot or too cold. You might describe the weather temperature by

34 Celsius 93 Fahrenheit

Why we measure weather

Celsius and Fahrenheit are scales used to measure temperature.

Scientists measure weather so that they can describe its characteristics exactly.

Weather and climate

-Weather includes the kinds of clouds in the sky and the amount of water in the air. -It includes the air temperature and how the wind is blowing.

Weather is what the air is like in a place at a single moment.

Weather

Clouds in the sky

Wind blowing

Climate is the pattern of weather in a place over many years.

1) Climate includes an area`s average temperatures.2) It includes the average

amount of precipitation.

climate

The climate of a place can change, but it takes many years.

Weather can change every day.

Factors That Affect Climate

sunlight

1

The amount of sunlight a place receives affects climate.Sunlight hits Earth directly at the equator.The equator is an imaginary line that circles Earth Pole. Places near the equator have warmer climates than places

farther from it.

Sunlight hits Earth at the equator

ocean

2

The ocean also affects climate.

Places near the ocean often have milder temperatures than places inland.

They receive more precipitation.

mountains

3

Mountains and other landforms may affect climate too.

Winter is mild and wet Winter is cold and dry

The west side of the mountain has mild, wet winters.

The east side of the mountain has cold , dry winters.

altitude

4

Altitude affects climate .

Altitude is the height above sea level. Temperature at the top of a mountain would be colder than temperatures at the bottom.

altitude

altitude

Factors that affect Local

Weather

Scientists study temperature, speed, and direction of wind to predict weather. They measure air pressure and the amount of moisture in the air too. They also look at wind and ocean currents.

Wind currents

The atmosphere is the blanket of air that surrounds Earth.

The atmosphere is made up of gases that have no color, taste, or odor.These gases have weight.

The air pressure : when the weight of the atmosphere presses down on Earth.

Heat from the sun, air pressure, and Earth`s rotation work together to cause wind.

The sun heats up the air in some areas more than other areas. Warm air has less pressure than cold air. Cool air sinks because it has more pressure. This makes warm air rise.

Winds form as air flows from areas of high pressure

areas of low pressure

Earth`s rotation influences the direction of the flow.

Jet streams are fast winds high above Earth`s surface.

Jet streams can affect local weather by changing temperatures, surface winds, and precipitation.

Jet streams

ocean currents

water cycle

The ocean affects climate weather

The ocean can absorb, store, and release vast amounts of heat.

Changes in ocean temperatures help produce hurricanes, floods, droughts, and other severe weather events.

Ocean currents are bodies of water that move in a certain direction. Winds blowing across the ocean`s surface help produce waves. Waves cause currents. Currents affect weather and climate by carrying the ocean`s

heat from place to place.

1

23

The Red arrows show warm currents.The blue arrows show cold currents.

Tools for Measuring Weather

Scientists use a number of tools to help them measure and describe weather.These tools help them predict what the weather will be like.

Anemometer measures wind speed Wind vane shows the direction from which the wind is blowing.

anemometer

Wind vane

Hygrometer measures how much water vapor is in the air.Humidity is the amount of water vapor in the air.

is low when air is dryhumidity is high when air has more water vapor in it.

hygrometer

Rain gauge measures how much rain has fallen.

Barometer measures air pressure.Changes in air pressure are clues to the kind of weather that is on the way.

Low air pressure means the weather will be: cloudy rainy

High air pressure means fair weather with:

sunny clear skies