Transcript Sun notes
The Sun’s Effect on Weather Contents The Sun’s Key Roles Effects on Earth’s weather Moving Air: The Wind Evaporation Hurricanes What is the Sun?? The Sun is a star, the closest star to planet earth. It is the largest object in the solar system, contains 99.8% of the total mass. It is estimated to be about 4.5 billion years old. Let’s take a look!! http://www.flickr.com/photos/gsfc/4445502369/in/set 72157623527696147/ The Sun’s Key Roles The sun supplies light and heat to our solar system. The sun is the Earth’s major source of heat energy. The Sun’s heat sustains life and controls our climate. The Sun’s Key Roles The Sun keep the temperature of most of the Earth’s surface at 51 to 49 degrees Celsius. – Most living things can only survive at 0 to 49 degrees Celsius. Did You Know: If the amount of sunlight reaching the Earth was cut by 1/10th, the oceans would turn to ice and life on Earth would cease to exist. Sun’s Effect on Weather The Sun is a major contributor to the world’s weather. The Sun’s heat warms the Earth’s land and water surfaces. The Earth absorbs the heat and releases it into the atmosphere, which heats the air above, and causes moving air. The movement of air causes winds which lead to weather changes. Sun’s Effect on Weather The Wind The absorption and release of heat energy into the atmosphere results in moving air, also known as Wind. The air moves, because the surface is unevenly heated. (some surfaces absorb heat faster than others) With movement, the air pressure (weight of air pressing on everything around it) changes, these changes affect weather. The Wind: Sea Breeze On a Beach: When land heats up faster than water, air above land becomes warmer than air above water. The warm land air rises, and is replaced by cool moving air from above the water. This is known as a breeze (or Sea Breeze) This type of air movement can happen anywhere where the surfaces are unevenly heated. The Wind: Sea Breeze Evaporation One factor that affects air and weather is water vapor. – Creates Air Moisture Evaporation is the process of changing liquid to gas. When Earth’s liquid water (oceans etc…) evaporates, it releases gas called water vapor. Heat from the Sun speeds up evaporation Evaporation The water vapors are held in the atmosphere, as air cools, the vapors become condensation (tiny droplets of water that form clouds) When the droplets grow larger and get too heavy, they fall back to Earth as precipitation: – rain, snow, hail, or sleet. Evaporation Water vapors in the air causes humidity. Humidity and temperature combined causes moving air masses, which results in weather front. – Cold Front – moving mass of cool air – Warm Front – moving mass of warm air – Evaporation and Air Movement Water vapors in the air cause humidity. Humidity and temperature combined causes moving air masses, which results in weather fronts. A front refers to the “front or leading” edge of a moving air mass: Cold Front – leading edge of a mass of cool air Warm Front – leading edge of a mass of warm air Let’s take a look at this process, click on the umbrella!!! Hurricanes Weather Fronts can lead to severe weather, such as Hurricanes. Hurricanes are large, violent tropical storms with wind speeds greater than 117km/hr Hurricanes begin as thunderstorms over warm water, the heat from the water, wind, and moisture help fuel the storm. Hurricanes Hurricane winds move counterclockwise, while the eye of the storm (middle) remains calm. Let’s take a look at the movement of a hurricane. – http://www.teachertube.com/viewVideo.php?title=H urricane_Ike_by_3D_Weather_Globe&video_id=49 703 Lesson Recap: The Sun’s Key Roles Effects on Earth’s weather Moving Air: The Wind Evaporation Hurricanes Online Resources www.HurricaneK atrina.com www.teachertube .com www.Google.com http://nineplanet s.org/sol.html http://www.window s2universe.org/sun/ solar_atmosphere.h tml http://www.intellica st.com/Local/WxM ap.aspx?weather=h dVisSatIRBlend