Investigating Weather Systems

A Review

Developed by Carol Swink and Zebetta King with modifications for student review

Weather Instruments

• Thermometers measure air temperature.

• A barometer measures air pressure.

• A psychrometer measures relative humidity, using the cooling effect of evaporation.

Weather Instruments• An anemometer, like the one shown in the picture, measures

wind speed.

• Weather balloons measure weather conditions higher in the atmosphere.

• Meteorologist place all of their data that they collect on to a weather map. By means of certain symbols, a single weather map can indicate atmospheric conditions above a large portion of the earth's surface.

Seasons Content Blast

• Earth is tilted about 23.5 degrees on its axis- this tilt is the cause of our seasons

• As the Earth orbits the Sun, different parts of the planet are tilted toward the Sun. Therefore, varying amounts of heat occur around the world at different times of the year.

Just for Fun!

For some reason, everyone but Lenore got the wrong answer on the science test. “Tell me,” the teacher asked her after returning the papers, “how did you know that heat causes objects to expand, and cold causes them to shrink?”“ Because I’m no dope,” she said. “In the summer, when it’s hot, the days are longer. And in the winter, when it’s cold, they’re shorter.”

Jeff Rovin

Teachers Jokes, Quotes, and Anecdotes, p.217

Just Dew It! Content

• Dew point = moisture in the air

• Maximum amount of water vapor the air can hold depends on the temperature of the air (cool air cannot hold as much water vapor as warm air)

• Most of the water in the atmosphere gets there through evaporation

Just Dew It! Content

• When warm air with water vapor begins to cool, the air begins to form droplets.

• When water droplets begin to form, the air is known as “saturated.” The temperature when this happens is called the dew point.

• Humid days = days air temperature and dew point are close

• Why do you feel humid? Water vapor surrounding us prevents perspiration from evaporating easily

What is Convection?

"Convection" has several, related meanings in weather....but it always involves rising air. It usually refers to "moist convection", where the excess water vapor in rising air parcels condenses to form a cloud. The heat released through this condensation can help to sustain the convection by warming the air further and making it rise still higher, which causes more water vapor to condense, so the process feeds on itself.

Step by Step CONVECTION

• Rising air• Extra water vapor in the rising air condenses and

forms a cloud• Heat is released through this condensation• This heat warms the air further and makes the air

rise (warm air rises)• When the air rises, more water vapor condenses• The process continues…

The Water Cycle

Model the Water Cycle

• You can model the water cycle using a clear rectangular container (the size of the Carolina Land and Water tray is great).

• Put potting soil in half of the tray. Make sure the soil is at least one fourth of the way up the side of the tray.

• Place plastic wrap over the top of the container (instead of the lid).

• Place a bag of ice over the land (on top of the plastic wrap). Have students observe and record data.

What Drives the Weather?

• Heat of the sun

• Latitude and insolation

• General circulation of atmosphere

• Warm winds spread excess heat toward poles

• Cooler air returns

Cloud Types

Stratus Clouds The word stratus

comes from the Latin word that means "to spread out." Stratus clouds are horizontal, layered clouds that stretch out across the sky like a blanket.

More on STRATUS Clouds

• Sometimes a layer of warm, moist air passes over a layer of cool air. Stratus clouds often form at the boundary where these layers meet.

• Where these two layers of air meet, the warm air is cooled. If the warm air is cooled below its dew point, the excess water vapor condenses to form stratus clouds.

• Stratus clouds may extend for many kilometers across the sky.

Cloud Types

• .Cumulus CloudThe word cumulus comes from the Latin word for a heap or a pile. Cumulus clouds are puffy in appearance. They look like large cotton balls. Cumulus clouds usually form when warm, moist air is forced upward. As this air rises, it is cooled. If it is cooled below its dew - point temperature, condensation will occur.

More on CUMULUS Clouds

• Largest cumulus clouds formed by very strong upward movements of warm, moist air

• The size of cumulus clouds depends on two factors:– Force of the upward air movement– Amount of moisture in the air

Cloud Types

• . 

Cirrus CloudsCirrus clouds are a third general type of cloud. The word cirrus comes from the Latin word for a tuft or curl of hair. Cirrus clouds are very wispy and feathery looking. They form only at high altitudes, about 7 km above the earth's surface.

What is Climate? • Climate - overall weather of an area; determined

by temperature and rainfall• Koeppen Climate Classification is one of the

oldest and most often used climate classification systems. Based on vegetative indicator species, it is useful for gaining a mental map of the global distribution of climatic events such as temperature and precipitation.

What factors influence climate? Six main factors control temperature and rainfall

1. LatitudeHigher latitude = lower average temperature and larger annual temperature ranges

2. Altitude- temperature decreases with altitude3. Land and sea

Continental climates = large yearly temperature ranges (interior of continents)Maritime climates = small yearly temperature ranges

4. Prevailing WindsPrevailing westerlies, west coast have cool summers/mild winters and east coasts

have hot summers/cold winters

5. TopographyMountains block winds

6. Ocean currentsWarm currents bring warm temperatures while cold currents bring cold temperatures

• What will greatly influence the temperature from any location when striking the Earth’s surface?

• Sunlight

• What source of energy drives all weather?

• The Sun

• Seasonal differences on Earth result from differences in the amount of the Sun’s energy that hits Earth’s surface. Why does this occur?

• Because of the tilt of the Earth as it revolves around the Sun.

• What do measurements of local weather conditions indicate?

• These measurements indicate relationships and predictable patterns.

• What is the relationship between air temperature and elevation?

• Air temperature decreases as elevation increases.

• What is wind?

• Wind is moving air that results from the uneven heating of the Earth’s surface and differences in air pressure.

• Which are components of weather that interact in weather systems and are interconnected both locally and globally?

• A. the Sun’s energy

• B. proximity to water

• C. elevation

• D. air pressure

• All of the above

Weather Resources

•

http://www.davidson.k12.nc.us/webquests/weather/weather.htm

Weather WebQuestFifth grade students' science curriculum includes a goal that states "the learner will build an understanding of weather and climate". This is a comprehensive webquest designed to be used over a period of days or teachers may choose to focus on only one area.

Internet Weather Resources Information Please Weather Page http://www.infoplease.com/weather.html• Explore weather disasters, climate, weather extremes, meteorology and measurement, weather

and environment.Intellicast http://www.intellicast.com/• The intellicast website contains weather forecasts and satellite images.• Within the Intellicast site:• 2) Weather 101 http://www.intellicast.com/DrDewpoint/wx101/• 3) Weather Q & A http://www.intellicast.com/DrDewpoint/Q_A/.Meteorology Guide• http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/home.rxml• This guide from the University of Illinois provides links to excellent resources for both

students and teachers. Topics include light and optics, clouds and precipitation, forces and winds, air masses and fronts, weather forecasting, severe storms, hurricanes, el nino, and hydrologic cycle.

 

Internet Weather ResourcesNational Weather Service http://www.nws.noaa.gov/• This site links to regions information for the United States as well as International resources. You'll

also find specialized centers for particular weather topics.• Related Websites:• 2) NOAA Central Library http://www.lib.noaa.gov/docs/education.html• 3) NOAA Photo Library http://www.photolib.noaa.gov/Scholastic - Research Tools - Weather

http://teacher.scholastic.com/researchtools/articlearchives/weather/index.htm• Explore a dozen articles on topics related to weather.• Within the website:• 2) Weather Prediction http://teacher.scholastic.com/researchtools/articlearchives/weather/

predict.htmSERCC http://water.dnr.state.sc.us/climate/sercc/education.html• Explore weather resources for all grades. Specific resources are focused on intermediate grades.• Within the website:

Internet Weather Resources Creative Climates• http://www.nationalgeographic.com/familyxpeditions/activities/15/15.html• Explore the climates of the world. This website has information and activities for

different grade levels related to the different climate regions.• Other Climate Websites:• 2) Climatic Extremes and Weather EventsWeather: What Forces Affect Our Weather? http://www.learner.org/exhibits/weather/• Explore this Annenburg sponsored project on weather including the atmosphere,

the water cycle, powerful storms, ice and water, forecasting, our changing climate, and related resources.

Weather World http://www.ems.psu.edu/WeatherWorld/• Explore world weather information and weather features, weather people,

educational materials, kid's resources, and other information.