Transcript Chapter 14
Climate 14.1 What is Climate? Climate: The long term weather patterns of an area. Normals: Standard values for a location (30 year average). This is what gives us the average daily high and low temps. Three main factors that cause climate: 1. latitude: -The more distance from the equator = colder average temperatures. Tropics: Area of latitude between 23.5degrees north and South latitude. Temperate zone: between 23.5 and 66.5 North and South Polar zone: Between 66.5 and 90 North and South Latitude. 2. Topographic Effects: -Coastal areas are cooler in the summer and warmer in the winter than inland regions (due to the high specific heat of water). -Climbing in altitude will decrease the temperature Orographic lifting -Windward side of mountain is wet (ex Seattle) -Leeward side of mountain is dry (rain shadow) 3. Air Masses: -The collision of air masses (fronts) provides a range of weather from mild precipitation to storms -The air masses themselves carry the two characteristics of temperature and humidity. 14.2 Climate Classification Koeppen Classification system: Classifying climates on the basis of temperature, amount of precipitation and to a lesser extent types of vegetation. 14.2 Climate Classification The following is a list of the various climates: -Tropical: Warm and often wet -Mild: Found near water and are humid -Dry: More evaporation then precipitation -Continental: 3 sub types, warm summer, cool summer and sub arctic -Polar: Passed the Continental climates 66.5 degrees North and south latitude. -High elevation: A type of a micro climate (Local climate different from main regional climate) where you climb in elevation and it is colder 14.2 Climate Classification MicroClimates: A localized climate that differs from the main regional climate. Heat Islands: The presence of many concrete buildings and large expanses of asphalt can create an area of higher temperatures. ex NYC is often 10 degrees warmer than it’s surrounding suburbs. 14.3 Climate Changes Ice Ages: Period of extensive Glacial coverage The last one ended 10,000 years ago *Created most of the lakes in NY This represented an average global drop in temp of 5 degrees Featured below is the rare bionic penguin which moves really, really fast. 14.3 Climate Changes Short term Climatic Changes Seasons: Caused by variations in sunlight both in duration and angle. This is caused by the tilt of the Earth as it revolves around the Sun. ***Some scientists have speculated that the enormous penguin population in the South Pole has caused this tilt. JK people, JK. 14.3 Climate Changes We apologize for the notes on the previous page, those responsible have been sacked. El Nino: Warm ocean current that occasionally develops off the western coast of South America. This can alter the normal storm track and bring storms to Southern North America. ***No, really, a penguin once bit my sister, it was awful! 14.3 Climate Changes We apologize for the notes on the previous page, those responsible for sacking those responsible, have been indeed been sacked. Changes can be natural: 1. Solar activity can vary. A decrease in sunspot activity has been linked to cooler temperatures, Maunder Minimum: From 1645-1716, few sun spots were detected, resulting in the “Little Ice Age” 2. Earth’s orbit can change. In a 100,000 year cycle Earth’s orbit goes from elliptical to circular (warmer temps to cooler temps). 3. Earth’s Tilt varies: between 22.1-24.5 over 41,000 years 4. Earth’s Wobble: Over a period of 26,000 years, the Earth changes its tilt direction. In about 14,000 our “north star” will be Vega, not Polaris. Volcanic Activity: Dust from explosions can cool temperatures 14.4 The Human Factor The Greenhouse Effect: When radiation from the sun is trapped in Earth’s atmosphere by “Greenhouse gases” such as carbon dioxide, water vapor, methane, and nitrous oxide. The Sunlight (short wave: more intense) is strong enough to go through the atmosphere, but when reflected off of Earth’s surface, turns into infra red (long wave: not intense) and can not escape. This acts like a greenhouse in which the heat is trapped inside. This activity can result in Global Warming. As trees are cut down, this increase the amount of CO2 in the atmosphere, and will speed up the process. The Ice caps could melt, and flooding will occur. This would be very bad for penguins. 1. Which is not a variable that greatly affects climate? A. Distance from the Sun B. Topography C. Air masses D. Latitude 2. Which is not a variable that greatly effects Long term climate change? A Solar activity can vary B. Earth’s orbit can change C. Earth’s Tilt varies D. Solar and lunar eclipses. 3. Which is not part of the Koeppen Classification system? A. Temperature B. vegetation. C. Amount of precipitation D. Air Currents 4. What happens to Sun light after it hits the Earth? A. It turns into infrared radiation B. It is all reflected by the clouds C. It is all absorbed by water D. The ozone layer blocks all incoming radiation ***Bonus Draw a diagram showing the concept of global warming. Be sure to show a difference in the wave length of the in-coming solar radiation vs the out going radiation.