The Atmosphere Are weather and climate the same thing????? So what's the difference Weather is constantly changing, and it refers to the state of the atmosphere at any given time and place. Climate is based on observations of weather that has been collected over many years. Climate helps describe a place or region. What makes up our atmosphere Air Water vapor Ozone Pollutants Air is a mixture of different gases and particles, each with its own physical properties Water Vapor The source of all clouds and precipitation. Has the ability to absorb heat and solar energy Dust Some examples of dust particles are pollen, spores, and seeds Most dust particles are found in the lower atmosphere near their source Dust particles act as a surface for water vapor to condense on This is essential for the formation of clouds and fog Ozone Layer Ozone is concentrated in the stratosphere, between 10 and 50 kilometers Ozone absorbs most of the UV rays from the sun Ozone absorbs most of the UV light from the sun. UV light is very harmful because it can damage the genetic material in living cells. Ozone Eaters CFCs (chloroflourocarbons) are man-made chemicals found in spray cans and refrigerator coolants. The Ozone Hole In 1985, a study showed that the ozone layer above the South Pole had thinned. As ozone decreases, more UV light hits the Earth. UV light can kill or damage skin cells. Stopping the Thinning In 1987, many nations agreed to stop producing CFCs. This meeting was called the Montreal Protocol. It appears that the thinning of the ozone layer has slowed. Human Influence Emissions from transportation vehicles account for nearly half the primary pollutants by weight. Height and Structure of the Atmosphere Atmospheric changes Atmospheric pressure is the weight of the air above At sea level the average pressure is slightly more than 1,000 millibars One half of the atmosphere gradually merges with outer space Height and Structure Continued Temperature changes The atmosphere is divided into five layers based on temperature Troposphere Stratosphere Mesosphere Thermosphere Exosphere Troposphere The bottom layer Temperature decreases with an increase in altitude All weather occurs in this layer The thickness of the troposphere varies with latitude, but the average thickness is 12 kilometers The outer boundary of the troposphere is called tropopause Stratosphere The temperature remains constant to a height of 20 kilometers then increases until the stratopause The stratopause occurs at about an altitude of 50 kilometers The reason for the increase in temperature is the abundance of ozone Mesosphere The temperature decreases with altitude until the mesopause The mesopause is at a height of 80 kilometers Thermosphere Contains very little of the atmospheres mass In this layer the temperature rises as high as 1,000 degrees Celsius Exosphere and Ionosphere The Exosphere begins at a altitude of around 400 kilometers A transition zone between earths atmosphere and space The ionosphere and the exosphere together are known as the thermosphere Now its your turn You have 10 minutes to draw your home and label the layers of the atmosphere. Be sure to include the ozone layer and label the height of each layer. The Earth-Sun Relationships Solar energy is not distributed evenly over the earths surface The unequal heating of the earth drives currents and creates winds Energy from the sun is the most important control of our weather and climate The Earths Principal Motions Rotation is the spinning of the earth on its axis The planet rotates once every 24 hours producing a daily cycle of daylight an darkness Revolution is the movement of earth in its orbit around the sun The Seasons There is an annual shift in the solar angle or altitude of the sun The Causes of the Seasons The tilt on the earths axis is the cause of the seasons In the northern hemisphere the earth is tilted toward the sun in the summer In the southern hemisphere the earth is tilted away from the sun The northern hemisphere receives more sunlight in the summer than in the winter Distance has no effect of the seasons Why are summer days longer than winter days The Angle of the Sun The angle of the suns rays also plays a part in the seasons: The angle of the sun makes a difference in how many atmospheres that rays have to travel through. If the sun is directly overhead, the rays only have to travel through one atmosphere. The angle will change the intensity the suns rays will hit the surface. Summer Solstice In the summer solstice, the sun is directly over the Tropic of Cancer, and occurs on June 21 or 22 Winter Solstice The sun is directly over the Tropic of Capricorn, and occurs on December 21 or 22 Autumnal Equinox The sun is directly over the equator and occurs on September 21 or 22 Vernal Equinox The sun is directly over the equator and occurs on March 21 or 22 Temperature Energy Transfer Heat is the energy transferred from one object to another because of a difference in the objects temperature Temperature is a measure of the average kinetic energy of the individual atoms or molecules in a substance Three mechanisms of energy transfer as heat are: conduction convection radiation. Conduction is the transfer of heat through matter by molecular activity. Convection is the transfer of heat by mass movement or circulation within a substance Radiation is the transfer of heat through space by electromagnetic waves that travel out in all directions. What happens to solar radiation? Some energy is absorbed by the object Some energy is reflected Some energy is scattered Reflection occurs when light bounces off an object. Reflection radiation has the same intensity as incident radiation. Scattering produces a larger number of weaker rays that travel in different directions. Cloud coverage and temperature. Did you know cloud cover can greatly impact who the temperature of an area changes. Albedo is the fraction of total radiation that is reflected by any surface. Many clouds have a high albedo and therefore reflect back to space a significant portion of the sunlight that strikes them. At night they can hold heat and during the day they can reflect it. Important Temperature Factors The most important temperature controls are: Specific heat Altitude Geographical Position Ocean Currents Specific Heat Land heats more rapidly and to higher temp than water and cools more rapidly than water. Specific heat: water>land. Land surfaces are opaque so heat is only absorbed at the surface. Water is transparent so heat penetrates for a depth of many meters. Water Factors Water is constantly mixing warm and colder waters. Evaporation from water bodies is greater than from land surfaces. Evaporation from water bodies is greater than from land surfaces Altitude Altitude: higher altitudes are generally cooler than an elevation that is close to sea level Geographical Positions Windward coastal location subject to prevailing winds experiences considerable different temp. from coastal location where prevailing winds are directed from the land toward the water. Mountains can act as barriers Isotherms Isotherms are lines on a weather map that connect points where the temperature is the same. They are typically placed at intervals of 10 degrees Fahrenheit. Create and isotherm map Today you will create your own isotherm map.