# Welcome to Science Unit 1 Water Cycle and Weather 4 th Grade Mr. Summerlin.

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Welcome to Science Unit 1 Water Cycle and Weather 4 th Grade Mr. Summerlin

Three states of matter: Soid liquid gas Three states of water Solid ice liquid water water vapor (gas )

Students should know the two different temperature scales (Farenheit and Celsius). Three states of water Solid ice liquid water water vapor (gas ) Water freezes at 32 degrees F or at 0 degrees Celsius. It’s important for students to understand that these two are the same temperature measured by different scales. An example is to remind them that a yard or 3 feet (American customary unit) is about the same length as one meter (Metric system)

Students should know the two different temperature scales (Farenheit and Celsius). Three states of water Solid ice liquid water water vapor (gas ) Important note: we will be aware that water evaporates as it boils, but water DOES NOT NEED TO BOIL in order to evaporate. The addition of any heat to water speeds up evaporation.

Condensation is in the clouds. Clouds are condensation.

Parts of the water cycle

Important for students to understand that the heat is needed for evaporation (liquid water changes to water vapor-gas). The heat of the sun drives the water cycle. The majority of evaporation on earth is caused by the sun evaporating ocean water. This creates our weather patterns.

Clouds are condensation. We will say Cold Condensation Clouds. This will help students remember that colder air or a colder temperature is needed for condensation (the water vapor-gas changes back to liquid water. Clouds are bundles of tiny droplets of water or ice. They will remain in the cloud until they are too heavy. The droplets form on tiny particles of dust or sand.

Precipitation falls from the clouds as rain, snow, sleet, or hail.

Can you find the parts of the water cycle that happen during your monthly shower?

Why do I always have to use a napkin under my cold drink? Does every cup in the world have a leak?????

Most students understand the condensation, but think that it somehow comes from inside the glass. Important to understand that it comes from water vapor in the air of the room outside of the glass.

The weather map and symbols can be confusing for students because the H and the L do not mean what you think they should mean. I didn’t fully understand these until a few years ago.

Common Misunderstanding : The H and the L DO NOT tell you about the temperature. The H DOES not mean hot.

The H and the L tell you about how much pressure the air is under. Air under high pressure (H) means the air is stable and will not change quickly.

High Pressure (H) sounds bad, but it is actually what we enjoy. A high pressure system gives us gentle rain and lots of clear weather. Children who like recess want a high pressure system!

Air under low pressure (L) is unstable air, and can change quickly. This is particularly true when the two types of air meet. Notice the bad weather near the two (L)s

Warm air Warm front cold air cold front These symbols tell you about the air temperature. The symbol shaped like suns show you warm air, while the symbols shaped like icicles show you cold air.

Warm front plus cold front = stationary front

H High air pressure Air is stable. Will not change quickly….nice weather. Children like a High Pressure system

L low air pressure Air is NOT stable. Will change quickly….can cause severe weather Children DO NOT like a Low Pressure system

Anemometer Measures Wind speed How fast wind is blowing.

Barometer Measure air pressure High pressure or low?

Wind vane Weather vane Tells direction of wind only

Rain guage Tells inches of rainfall

Cumulus Cumulonimbus Cirrus Stratus 4 types of clouds to learn

Cumulus Cumulonimbus Cirrus Stratus Cumulus clouds are the white fluffy clouds that kids have always drawn. Cumulus clouds are good weather, blue sky clouds. They are low in the sky, and are usually a sign of a high pressure system (H) and happen during fair weather.

Cumulonimbus Cirrus Stratus Cirrus clouds are thin and look like feathers. They are so high in the sky that they are made only of ice crystals. They usually predict fair (good) weather, and appear in clear blue skies.

Cumulus Cumulonimbus Cirrus Stratus Stratus clouds are rain clouds that form low in the sky. Stratus clouds form in large flat layers like blankets. These are not dangerous, and make grey sky- days of long steady rain.

CumulonimbusCirrus Stratus Cumulonimbus clouds are dangerous thunderstorm clouds. Cumulonimbus clouds can create dangerous weather. They happen when air under high pressure (H) meets air under low pressure (L)

CumulonimbusCirrus Stratus The unstable air (L) allows the cumulonimbus cloud to grow upward very quickly. A single cloud is both low to the ground and high in the atmosphere, so it has many temperatures in the same cloud.

CumulonimbusCirrus Stratus The movement and friction creates the electrical charge (lightning) and the different temperatures allow water to freeze and fall as hail in the summer.

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