Chapter 3 Insolation and Seasons January 29th (2).pptx

Chapter 3 Solar Energy and Earth-Sun Relationships Announcements: Cengage Chapter 2 due Wednesday January 31st at 11:59 PM Cengage Chapter 3 due Sunday February 4th at 11:59 PM* NO CLASS February 5th! *I will be out of town, if you have any urgent questions, please email Gavin Chapter Objectives By...

Chapter 3 Solar Energy and Earth-Sun Relationships Announcements: Cengage Chapter 2 due Wednesday January 31st at 11:59 PM Cengage Chapter 3 due Sunday February 4th at 11:59 PM* NO CLASS February 5th! *I will be out of town, if you have any urgent questions, please email Gavin Chapter Objectives By the end of this chapter, you should be able to: 03.03: Describe the factors that affect the intensity and duration of incoming solar radiation. 03.04: Diagram Earth’s orbital positions around the sun during the solstices and equinox days, including the orientation of the axis and the circle of illumination. 03.05: Outline the relationships of the Tropics of Cancer and Capricorn and the Arctic and Antarctic Circles to solar radiation and the seasons. 03.06: Explain how the amount of daylight hours varies by latitude and by hemisphere over the year. 03.07: Describe the factors that cause the seasons to be reversed between the Northern and Southern Hemispheres. The Earth-Sun System The sun radiates energy into space at an almost steady rate. A planet’s rate of receiving energy from the sun is known as the solar constant and has been measured with great precision outside Earth’s atmosphere by satellites. The sun radiates electromagnetic energy that travels at the speed of light in a range of wavelengths, called the electromagnetic spectrum About 41% of the sun’s energy comes in as light rays that we can see called the visible spectrum, where their specific wavelength bands distinguish different colors. The Earth-Sun System Solar radiation: Shortwave (SW) radiation Gamma X-rays Ultraviolet (UV) radiation Visible light Near infrared (IR) Longwave (LW) terrestrial radiation Thermal infrared (IR) Microwaves TV and radio waves The Earth-Sun System Earth’s movement in space: Rotation and Revolution Rotation: Revolution: Turning of Earth on its axis Movement around the sun Every 24 hours Perihelion—closest approach Eastward direction Aphelion—farthest Speed varies depending on latitude Approximately 365.25 days in a year Circle of illumination Leap year The Earth-Sun System Earth’s movement in space: Rotation and Revolution Rotation: Turning of Earth on its axis Every 24 hours Eastward direction Speed varies depending on latitude Circle of illumination The Earth-Sun System Earth’s movement in space: Rotation and Revolution Revolution: Movement around the sun Perihelion—closest approach Aphelion—farthest Approximately 365.25 days in a year Leap year Insulation, Sun Angle, and Duration Insolation—incoming solar radiation Main source of energy on our planet Seasonal variations in temperature due primarily to fluctuations in insolation A location will receive more insolation if 1.the sun’s rays strike at a Insulation, Sun Angle, and Duration How does the amount of insolation change the weather in certain locations? Insulation, Sun Angle, and Duration Why do we have seasons? Seasons are controlled by the amount of solar energy striking our tilted planet Nearest to the sun (147 million km) in January Longest from the sun (152 million km) in July Caused by: Length of daylight The intensity of sunlight that reaches the surface Insulation, Sun Angle, and Duration Variations of insulation with latitude: In general, annual insolation tends to decrease from lower latitudes to higher latitudes Other factors impact insolation Insolation received by Earth’s system is an important factor in understanding the atmosphere, climate, ocean, soils, and vegetation