Meteorology - Weather Science
1. Explain that air surrounds us, takes up space, moves around us as wind, and may be measured using barometric pressure.
2. Identify how water exists in the air in different forms (e.g., in clouds, fog, rain, snow and hail).
3. Investigate how water changes from one state to another (e.g., freezing, melting, condensation, evaporation).
4. Describe weather by measurable quantities such as temperature, wind direction, wind speed, precipitation, and barometric pressure.
5. Record local weather information on a calendar or map and describe changes over a period of time (e.g., barometric pressure, temperature, precipitation symbols, cloud conditions).
6. Trace how weather patterns generally move from west to east in the United States.
7. Describe the weather which accompanies cumulus, cumulonimbus, cirrus and stratus clouds.
( 50 days ago )
Water Cycle Video
( 24 hours ago )
Climates
( 13 days ago )
UDL6- Summary
Air is a mixture of gases, mostly nitrogen and oxygen. It also contains small amounts of carbon dioxide, water vapor, and other gases. The blanket of air surrounding Earth is called the atmosphere. Earth’s gravity holds it in place.
The atmosphere has four different layers. The top layer gradually thins into empty space. To describe weather, scientists measure four properties of air.
- Air temperature rises with the surface below it.
- Humidity is a measurement of how much water vapor is in air. Air over oceans and lakes is usually very humid.
- Air pressure is the force of air pushing on an area. Cool air usually has higher air pressure than warm air.
- Air in motion is called wind. Winds blow from places of high pressure to places of low pressure. Because air pressure tends to change with air temperature, the uneven heating of Earth’s surface causes wind. Dark surfaces such as soil and city streets absorb heat well, so air above them tends to be warm. Light-color surfaces such as snow and water stay cool, so the air above them is cool too.
Clouds are made of millions of tiny water droplets or ice crystals. The droplets form from condensed water vapor and bits of dust or other material. Water-droplet clouds tend to have sharp, distinct edges. If the clouds are thick, they may be gray or black. Ice-crystal clouds are whiter. They tend to have fuzzy, less defined edges.
- Stratus clouds form in layers. Fog is really a stratus cloud that develops near Earth’s surface.
- Cumulus clouds are puffy clouds that appear to rise from a flat bottom.
- Cirrus clouds are made of ice crystals and have wispy shapes, like feathers. The amount of the sky covered by clouds is called cloud cover.
On a weather map, shaded circles describe the cloud cover.
People use many tools to measure the weather.
- A thermometer measures air temperature. Heat expands the mercury in the thermometer’s tube.
- A weather vane measures wind direction. A barometer measures air pressure.
- A hygrometer measures humidity.
- An anemometer measures wind speed. The height of the water collected in a rain gauge tells how much rain has fallen.
( 24 days ago )