Lushman's Science



Science 2200Weather Test ReviewThe following review sheet does NOT contain all the material that will be on the upcoming quiz/test. You must also understand the notes given, questions assigned, and sections of the text covered. If you have missed notes it is your responsibility to make up for the material you missed.Unit 2: Weather Dynamics- This section of the course will deal with daily atmospheric conditions (weather) and long term conditions (climate).- Understanding weather is a type of Earth Science (Geology).Weather Stations- All weather stations use the same basic devices:1. Thermometer – a device used to measure temperature. 2. Hygrometer – A device used to measure humidity. 3. Barometer – A device used to measure the atmospheric pressure. 4. Wind vane – Shows the direction of the wind.5. Anemometer – Measures the speed of wind. 6. Rain gauge – Records how much rain or snow has fallen. The Atmosphere- The atmosphere can be divided into 5 parts:1. Troposphere – The lowest level. It is the part of the air we live in. It reaches about 10 km up.2. Stratosphere – Between 10 and 50 km. The ozone layer and some clouds are located here.3. Mesosphere – Between 50 and 80 km. Temperatures decrease to -90oC.4. Thermosphere – Between 80 and 150 km. Temperatures begin to increase as the amount of energy from the sun increases.5. Ionosphere – 150 km to about 400 km. This is were the northern lights occur.Weather Terminology p.206-209- Weather systems are a set of temperature, wind, pressure, and moisture conditions. Weather systems are made of air masses that have the same temperature and humidity.- When two of these air masses meet they form a front between them.- A cold front forms when cold air pushes under warm air. Cold fronts usually mean stormy weather followed by cool, fair weather.- A warm front forms when warm air slowly rises over cold air. Warm fronts usually mean rain followed by warm humid weather.Weather Maps p.208-209- Most weather maps contain:1. Temperature – this may be in the form of lines or colour coded areas called isobars.2. Precipitation – this is often shown as little pictures. Snowflakes for snow, rain droplets for rain, etc. 3. Fronts – Cold fronts are drawn in blue with triangles. Warm fronts are drawn in red with semicircles. 4. High or low pressure areas – High pressure areas are formed when two air masses come together and prevent warm air from rising. This results in fair weather. Low pressure areas form when two air masses move apart. This allows warm air to rise and often results in rain. 5. The jet stream – this is a “tunnel” of wind in the upper troposphere that can be as fast as 500km/h. The jet stream forms when two air masses with different pressures meet high in the atmosphere. The jets stream is not always located in the same place. Where it is helps predict where storms will occur. Weather in Newfoundland and Labrador- In our province weather changes a lot so we can only make accurate predictions easily if we talk about long periods of time. E.g. Summer will be hot and winter cold. - Some things that make it difficult to predict weather in Newfoundland and Labrador are:1. The Labrador current - This brings cold water from the arctic to the coast. It cools down the land near the shore.2. The Gulf stream - This brings warm water from Mexico to the south coast. This warms up parts near the shore in the south.3. Influence of the continent - Land cools down faster and warms up slower than water. This means that areas far away from the ocean are usually colder than areas on the coast. This results in Gander being colder than St. John’s.4. Wind - There are few physical barriers to wind (e.g. mountains) in this province. Also strong ocean storms can increase the wind on land. This makes it windy, feel cold (wind chill), and results in weather systems moving quickly through our province.Climate of NLFactors that affect climate:Effect of Altitude: Gravity pulls air down toward the ground. This means as you go up a mountain the air gets thinner. Thinner air also means it feels colder.Latitude: In general the further north you go (increasing latitude) the colder it becomes as compared to more southerly locations.Relief: Is the shape of the landExample: Mountains receive more rainfall than low lying areasCloseness to water: Water heats and cools more slowly than land. So in summer, areas next to water will stay cooler and in winter warmer. A moderate climate with a smaller temperature range.Large bodies of water: oceans, seas, and large lakesThe Water Cycle p.212-213- Water cycles from a liquid or solid, to a gas and back again and is powered by the sun.- It is the sun’s heat that causes evaporation. After water evaporates it enters the atmosphere as a gas.- This gas rises, then meets dust in the atmosphere and condenses (turns to a liquid). This forms clouds.- When the liquid in the clouds becomes too heavy for the dust to hold, it falls as precipitation.Types of Precipitation p.212-2131. Rain - Large droplets of liquid water that fall from the sky.2. Drizzle - Small droplets of water that fall from the sky. It can form a thick blanket of moisture.3. Freezing rain - This starts as normal rain but freezes before it reaches the ground.4. Snow - Delicate crystals of ice that form in clouds and fall to the ground.5. Hail - Dense round pieces of ice that form in clouds and fall to the ground.6. Dew - Moisture that forms close to the ground, due to differences in air temperature.7. Frost - Ice crystals that form close to the ground, due to a drop in temperature. This can cause considerable damage to plants.Air Movement- Weather is caused by a combination of moving air and moisture. How long precipitation stays in an area, or how bad a storm is, depends on the wind.- There are three major types of moving air:1. Thermal - This is rising air caused by heating of the Earth’s surface.2. Sea breeze - This is wind cause by warm air rising over land near the ocean, during the day. When the warm air rises, cooler air from over the ocean moves in to replace it.3. Land breeze - At night the land cools off and air then moves out over the ocean.Global Winds p.230-231- Local wind is caused by warming of the Earth’s surface. When an area warms up, it causes the air above it to rise. Rising air pushes other air out of the way and that makes wind. (uneven heating!)- If we look at large sections of the Earth, the direction of the wind remains the same.- At high altitudes there are the jet streams. One in the North and one in the South.Prevailing winds: that blow predominantly from a single general direction over a particular point on the Earth's surface. Newfoundland to the West.Coriolis Effect: Deflection of the wind as a result of the earth's rotation. As air moves in the northern hemisphere, it is deflected to the right by the Coriolis force.- Without the circulation caused by the jet stream and prevailing winds, the North pole would be 25oC colder and the equator 14oC warmer. Wet areas would also be wetter, and dry areas would be dryer.Specific winds:Alberta clipper: a low pressure system that travels eastward from the prairies across the Great Lakes, picks up moisture and energy, finally making its way to eastern CanadaColorado low: is an intense low pressure system originating in the south central United States and travels to the eastern seaboard.Nor’easter: is a tropical low pressure system, heavily laden with moisture and energy, that travels in a northeasterly direction along the eastern seaboard.weather bomb: occurs when two or more low pressure systems combine to cause severe weather.Seasons- Seasons are caused by the tilt of the Earth.- As the Earth revolves around the sun one end is pointed toward the sun.- When the North pole of the Earth is pointed toward the sun, we have summer.- When the North pole of the Earth is pointed away from the sun we have winter.- The opposite is true of the seasons near the south pole.Day Length p. 226-227- In the summer days are longer, and in the winter days are shorter.- Days get longer in the summer because we are close to the North pole.- When the North pole is pointed toward the sun in the summer, we get more sunlight.- The day with the most sunlight (June 21st) is called the summer solstice. - When the North pole is pointed away from the sun in the winter, we get less sunlight.- The day with the least sunlight (December 22nd) is called the winter solstice.- Two times of the year days and nights are the same length.- When this happens in Spring (March 21st) it is called the Vernal equinox and in the Fall (September 22nd) it is called the Autumnal equinox. Affect of Altitude - Gravity pulls air down toward the ground. This means as you go up a mountain the air gets thinner. Thinner air also means it feels colder.Clouds p.228-229- All clouds begin with evaporation, however there are 3 main ways they can form:1. Convective – Clouds can form just from water evaporation in the local area. 2. Frontal – When two moving air masses with different temperatures meet, clouds form. 3. Orographic – When air is forced up a mountain it cools and water condenses. Often it also results in one side of the mountain (where the clouds form) being wetter than the other.- Clouds can be divided into three general types:1. Cumulus clouds – These are dense round fluffy clouds. 2. Stratus clouds – These are thinner clouds that are more spread out and form near the ground. 3. Cirrus Clouds – These form high in the sky and look like thin strips. Ocean Currents p.232-233- The direction of the ocean currents is caused by wind and the Earth’s rotation.- Since the sun powers the wind, the sun too affects ocean currents.- Ocean currents affect the temperature of land close by.- The difference in water temperature means it is colder in Nain than Ireland.- Sometimes currents change direction.- El Nino results when the currents in the Pacific ocean change direction. This brings warmer water and wind to the Americas, resulting in warmer weather and more storms.Weather TechnologyWeather satellite: a type of satellite that is primarily used to monitor the weather and climate of the EarthWeather balloon: a type of high altitude balloon that carries weather instruments to send back information by a small measuring device called a radiosonde.Radar: (Also called Doppler weather radar), is a type of radar used to locate precipitation, calculate its motion, and estimate its typeMeteorologists: study atmospheric conditions using many technologies to understand weather patterns and climateExtreme Weather p.236-240- Sometimes the weather is much different than usual and can be dangerous. That type of weather is called extreme.- There are 3 levels of warnings:1. Weather watch - The conditions are right for extreme weather to form. 2. Weather advisory - Extreme weather has been forecasted for the area. 3. Weather warning - Extreme weather is highly likely. Types of Extreme WeatherI. Thunderstorms - Thunderstorms form when warm air pushes high into the atmosphere. This forms large cumulus clouds called thunderheads. Thunderstorms go through 3 stages:1. Developing stage - Rain clouds develop.2. Maturing stage – Lightening and thunder happen. Sometimes there is heavy rain or hail.- Lightening can be 28,000 oC.3. Final stage – Less rain.- If there is a thunderstorm alert you should: Stay away from open doors and windows; Don’t touch any electrical appliances or pipes; Stay away from trees and power lines; If you are in water, head for the shore.II. Tornados - Tornados form from the worst thunderstorms. As the air rises it cools and the spinning speeds up (can reach 500Km/h).- If there is a tornado alert you should: Get inside a building, in a basement or room with no windows is best; Open windows on the opposite side of the building; That will prevent quick pressure changes which will stop the walls of the house from exploding.III. Hurricanes - When the wind reaches 199 Km/h or more it is a hurricane. Less is called a tropical storm.- If there is a hurricane warning you should: Board up windows; Store food and medical supplies; Reinforce buildings;Move inland.IV. Blizzards - A blizzard has wind higher than 55 Km/h and visibility is less than 0.2 Km.- If there is a blizzard warning you should: If stuck in a car, turn off motor to avoid carbon monoxide poisoning; Carry blankets, warm clothes, matches; Be prepared for a blackout and have supplies on hand.V. Floods - Floods are caused by excess water from rain, rivers or oceans.- If there is the possibility of a flood you should: If in flood zone, avoid fast-moving waters; Keep children away from drainage ditches; Watch for thunderstorms in flash flood areas.How Humans Affect the Weather- Weather is mostly the result of wind and water interacting in the atmosphere.- However human activities can affect what happens in the atmosphere.1. The hole in the ozone layer. - Chemicals used in spray cans and refrigerators break down ozone. Ozone prevents ultraviolet radiation from reaching the ground. If more UV radiation reaches the ground, some animals die and it is easier for humans to get skin cancer.2. Acid precipitation - Sulfur dioxide and nitrogen oxide in air pollution reacts with water in the atmosphere. This results in rain and snow that is acidic. This causes materials to wear out faster and some aquatic animals die.3. Global warming - Carbon dioxide in the atmosphere traps some of the heat from the sun. Extra carbon dioxide in air pollution is causing the Earth to get hotter faster. This also creates more powerful storms, like hurricanes.Questions1. How do clouds form? 2. What are the different types of clouds?3. What are the jet streams?4. How does the wind affect the weather?5. How do ocean currents affect the weather?8. What are the major types of extreme weather? What should you do if each type of extreme weather is forecasted for your area?9. How do humans make extreme weather worse?10. How can extreme weather change people’s lives?Questions - 21. What is the difference in weather and climate?2. What are some traditional ways to predict the weather? How are these different from modern ways?3. Describe the different parts of a weather station.4. Describe the layers of the atmosphere.5. How are cold and warm fronts related to weather?6. Which air masses would you expect to see in Newfoundland and Labrador in the summer? In the winter?7. Describe the different parts of a weather map.8. What things make it difficult to predict weather in Newfoundland and Labrador?9.What are the different types of breezes seen in Newfoundland and Labrador?10.Label a diagram of the water cycle.11.Describe the different types of precipitation. ................
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