The Atmosphere in Motion Chapter 10 Section 1: The Atmosphere Section 2: Earth’s Weather Section 3: Air Masses and Fronts The Atmosphere in Motion Before you Read Agree Agree Agree Disagree Page 1 The Atmosphere in Motion The atmosphere protects living things from harmful doses of ultraviolet radiation and xray radiation Earth is often referred to as the water planet Fast moving molecules transfer energy to slower moving molecules when they bump into them. The highest layer of the Atmosphere is the stratosphere. www.brainpop.com Section 1: The Atmosphere Vocabulary • Evaporation: process by which a liquid is • • • • converted to a gas. Atmosphere: layer of gasses surrounding Earth Aerosols: Solids, such as dust, salt, and pollen and liquid droplets, such as acids, that are suspended in the atmosphere. Water cycle: Never-ending cycle in which water circulates between Earth’s surface and the atmosphere. (Hydrosphere) Affect: to bring about a change in Page 2 Earth’s “Spheres” • Geosphere: the solid part of the earth consisting of the crust and outer mantle. • Hydrosphere: the watery part of the earth's surface, including oceans, lakes, water vapour in the atmosphere, etc. • Cryosphere: frozen part of Earth: the frozen part of the Earth's surface, including the polar ice caps, continental ice sheets, glaciers, sea ice, and permafrost • Atmosphere: gas around astronomical object: the mixture of gases that surrounds an astronomical object such as the Earth • Biosphere: planet Earth and its life: the whole area of Earth's surface, atmosphere, and sea that is inhabited by living things Section 1: The Atmosphere Atmosphere Provides Earth with all of the gasses necessary for life Page 3 Protects living things against harmful doses of ultraviolet and x-ray radiation Absorbs warmth from the Sun Section 1: The Atmosphere 80% • I. Examples of Aerosols 70% 60% Gasses – A. Solids • 1. dust • 2. salt • 3. pollen 50% 40% 30% 20% – B. Tiny liquid droplets 10% 0% Nitrogen Page 3 Oxygen • 1. Acids Section 1: The Atmosphere Layers of the Atmosphere: Page 4 Exosphere: Contains few atoms No clear boarder with space Ionosphere: contains electrically charged 500 km particles: Special part of the atmosphere found with the thermosphere. Thermosphere: Can reach temperatures of 85 km 1,700 degrees Celsius Mesosphere: contains little ozone, so it absorbs little heat Stratosphere: contains ozone layer 50 km Troposphere: Contains nearly all of Earth’s clouds and weather Earth’s Surface 0 km http://www.vtaide.com/png/atmosphere.htm 10 km Section 1: The Atmosphere Water Cycle: Page 4 • http://www.sweetwater.org/edu cation/watercycle.swf Condensation Precipitation Evaporation Runoff The Atmosphere in Motion Section 2: Vocabulary • Condensation: process of changing from a gas to a liquid • Humidity: amount of water vapor in the atmosphere. • Dew point: temperature at which air is saturated with water vapor and condensation can occur. • Relative humidity: measure of the amount of water vapor in the air compared with the amount that could be held at a specific temperature. • Indicate: make known or show; to be or give a sign of Page 5 Section 2: Earth’s Weather Difference Between Weather and Climate • Weather Weather describes whatever is happening outdoors in a given place at a given time. Weather is what happens from minute to minute. The weather can change a lot within a very short time. For example, it may rain for an hour and then become sunny and clear. Weather is what we hear about on the television news every night. Weather includes daily changes in precipitation, barometric pressure, temperature, and wind conditions in a given location. What is your weather like today? • Climate Climate describes the total of all weather occurring over a period of years in a given place. This includes average weather conditions, regular weather sequences (like winter, spring, summer, and fall), and special weather events (like tornadoes and floods). Climate tells us what it's usually like in the place where you live. San Diego is known as having a mild climate, New Orleans a humid climate, Buffalo a snowy climate, and Seattle a rainy climate. How would you describe the climate where you live? Section 2: Earth’s Weather Weather Factors: page 6 Cloud Cover Temperature Wind Speed Weather Factors Air Pressure Wind Direction Humidity Section 2: Earth’s Weather Energy’s Movement: Page 6 3. Cool air pushes warm air upward, creating a Convection Current 2. Air at the surface is heated by conduction Earth’s Surface 1. Earth’s surface is warmed by radiant energy from the Sun. Earth’s Weather Clouds: Page 7 Class Low Altitude 2,000 m or below Medium 2,000 m8,000 m High Above 8,000 m Examples Cumulus, stratus, nimbostratus Altocumulus, altostratus Cirrus, cirrostratus A type that can extend from low to high: cumulonimbus Section 2: Earth’s Weather Precipitation: page 7 Precipitation 1. rain 2. freezing rain 3. sleet 4. snow 5. hail Connect It! • How does conduction warm bare feet when a person walks on hot sand along a beach? Heat from the hot sand is transferred to the cooler bare feet as contact is made. Section 2: Earth’s Weather Wind Belts Page 7 Section 2: Earth’s Weather Wind Belts Page 7 • Question: What are global wind belts? • Answer: The global wind belts are formed by two main factors: the unequal heating of the earth by sunlight and the earth's spin. • The unequal heating makes the tropical regions warmer than the polar regions. As a result, there is generally higher pressure at the poles and lower at the equator. • Wind flows from high to low pressure. So the atmosphere tries to send the cold air toward the equator at the surface and send warm air northward toward the pole at higher levels. • The atmosphere breaks into three zones between the equator and each pole. These form the six global wind belts: 1) The Tradewinds, which blow from the northeast (NH) and southeast SH), are found in the subtropic regions from about 30 degrees latitude to the equator. 2) The Prevailing Westerlies (SW in NH and NW in SH) which blow in the middle latitudes. Most of North America fits into this belt and that is why our weather usually comes from west. 3) The Polar Easterlies which blow from the east in the polar regions. 60 degrees latitude. • • • • Temperature differences between land, air, and water • Water has a much higher heat capacity that do sands or other land materials, so water temperature will increase less than land temperature. • Water's high heat capacity prevents rapid changes in water temperature at night . • Air above the land and water surfaces is warmed or cooled by conduction with those surfaces. During the day, the warmer land temperature results in a warmer (therefore less dense and lighter) air mass above the coast as compared with the air mass over the surface of water. • As the warmer air rises by convection, cooler air is drawn from the ocean . The warmer air mass returns to sea at higher levels to complete a convective cell. During the day, there is usually a cooling sea breeze blowing from the ocean to the shore. The greater the temperature differences between land and sea, the stronger the land breezes and sea breezes. • After sunset, the air mass above the land quickly loses heat while the air mass above the water generally remains much closer to it's daytime temperature. When the air mass above the land becomes cooler than the air mass over water, the wind direction and convective cell currents reverse and the land breeze blows from land out to sea. • Land breezes and sea breezes result in elevated humidity levels, high precipitation, and temperature moderation in coastal areas. Global Patterns: Jet Stream • Jet streams are fast flowing, relatively narrow air currents found in the atmosphere at around 12 km above the surface of the Earth, just under the tropopause. • Ocean Currents Section 3: Air Masses and Fronts Vocabulary • Thunderstorm: storm produced by a cumulonimbus • • • • • cloud that has lightening and thunder. Air mass: large body of air that develops over a particular region of Earth’s surface. Front: boundary that develops where air masses of different temperatures collide. Tornado: violent whirling wind, usually less than 200 m in diameter, that travels a narrow path over land and can be highly destructive. Hurricane: large storm that begins as an area of low pressure over tropical oceans. Occur: to happen; to take place Page 8 Section 3: Air Masses and Fronts: Page 9 • Air masses that remain in one area for a few days pick up the characteristics of that area. For example, an air mass that stays over a tropical ocean will become warm and moist. Type of Front How it forms Cold Front Cold, dense air mass advances and pushes under warm air mass; the warm air is forced to rise. Warm Front Warm air advances into region of colder air, the warm, less dense air slides up and over the colder air. Stationary Front Warm air mass and cold air mass meet but neither advances. Occluded Front Fast-moving cold front overtakes a slower warm front. Section 3: Air Masses and Fronts: Page 9 High and Low Pressure Centers. Low Pressure forms High Pressure forms Air Sinks Moisture In air cannot Condense Air is dry with few clouds Air flows Moisture In air In and Condenses Rises Clouds Form; Precipitation follows Section 3: Air Masses and Fronts: Page 10 Severe Weather Thunderstorms Tornadoes Both precipitation Whirling winds Develop from Cumulonimbus thunder Clouds Move along narrow paths Form along lightning cold fronts Winds up to 500 km/hour Section 3: Air Masses and Fronts: Page 10 Severe Weather: Hurricanes 1. Wind gusts can exceed 250 km/h. Wind gusts cause most of the damage to buildings. 2. Storm surge is a dome of water driven onto land by the clockwise motion of the storm. Most of the deaths caused by hurricanes are drownings. 3. Beach erosion is caused by the action of water and wind combined. Beaches can be washed away or transported inland. Sun Exposure • • • • • • • • Do Not Burn Five or more sunburns significantly increases your risk of developing skin cancer. Avoid Sun Tanning and Tanning Beds UV light from tanning beds and the sun causes skin cancer and wrinkling. If you want to look like you’ve been in the sun, consider using a sunless self-tanning product, but continue to use sunscreen with it. Generously Apply Sunscreen Generously apply sunscreen to all exposed skin using a Sun Protection Factor (SPF) of at least 15 that provides broad-spectrum protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. Reapply every two hours, even on cloudy days, and after swimming or sweating. Wear Protective Clothing Wear protective clothing, such as a long-sleeved shirt, pants, a wide-brimmed hat, and sunglasses, where possible. Seek Shade Seek shade when appropriate remembering that the sun’s UV rays are strongest between 10 a.m. and 4 p.m. Remember the shadow rule when in the sun: Watch Your Shadow. No Shadow, Seek Shade! Use Extra Caution Near Water, Snow and Sand Water, snow and sand reflect the damaging rays of the sun, which can increase your chance of sunburn Watch for the UV Index The UV Index provides important information to help you plan your outdoor activities in ways that prevent overexposure to the sun. Developed by the National Weather Service (NWS) and EPA, the UV Index is issued daily in selected cities across the United States. Get Vitamin D Safely Get vitamin D safely through a diet that includes vitamin supplements and foods fortified with Vitamin D. Don’t seek the sun.