Chapter 13 Climates PDF

12/23/2024 Chapter 13 Brainstorm with your shoulder buddy: What are similarities and differences between weather and climate? 1 ...

12/23/2024 Chapter 13 Brainstorm with your shoulder buddy: What are similarities and differences between weather and climate? 1  12/23/2024 Annual Averages and Variations Climatology is the study of Earth’s climate and the factors that affect past, present, and future climatic changes. Climate describes the long-term weather patterns of an area. Copyright © McGraw-Hill Education Defining Climate What is climate? Climate is the pattern of weather that occurs in an area over many years. Climate is primarily determined by seasonal variations of temperature and precipitation. It determines the types of plants or animals that can survive, and it influences how people live. 2  12/23/2024 Annual Averages and Variations Normals The data used to describe an area’s climate include daily high and low temperatures, amounts of rainfall, wind speed and direction, humidity, and air pressure. The data are averaged on a monthly or annual basis for a period of at least 30 years to determine the normals, which are the standard values for a location. Copyright © McGraw-Hill Education Defining Climate Factors that affect climate 1. Latitude 2. Large bodies of water 3. Mountains 4. Cities 5. Air Masses 3  12/23/2024 Causes of Climate Latitude Latitude has a great effect on climate. The amount of solar radiation received on Earth decreases from the equator to the poles. Copyright © McGraw-Hill Education Defining Climate Large Bodies of Water It takes a lot more heat to increase the temperature of water than it takes to increase the temperature of land. Because of this, costal areas see small changes in temperature, and inland areas see larger change in temperature. San Diego is a coastal city in California, while Sacramento is more inland. Look at the differences in their average high and low temperatures. 4  12/23/2024 Causes of Climate Topographic effects Orographic lifting leads to rain on the windward side of a mountain. The leeward side is usually dry and warm. Water heats up and cools down more slowly than land. Copyright © McGraw-Hill Education Defining Climate Causes of Climate Air masses Air masses affect regional climates by transporting the temperature and humidity of their source regions. Copyright © McGraw-Hill Education Defining Climate 5  12/23/2024 Cities Large cities are warmer because streets, parking lots, and buildings absorb heat. Air pollution traps in heat. Free image from wikimedia.org Temperatures in cities can be 5 degrees higher than surrounding areas. How are climate zones classified? A climate classification system was devised by Wladimir KÖppen. He believed that looking at natural vegetation would give us clues to what the climate was like in an area. 6  12/23/2024 Koppen Classification System Climate Name Description Type A Humid tropical In A climates, every month is warm with a mean temperature over 18C (64F). The temperature difference between day and night is greater than the difference between December and June averages. There is enough moisture to support abundant plant communities. B Arid B climates have a chronic water deficiency; in most months evaporation exceeds precipitation. Temperatures vary according to latitude: some B climates are hot while others are frigid. C Humid C climates in midlatitudes, with distinct winter and summer seasons and enough moisture to support abundant plant communities. The winters are mild. Snow may fall mesothermal but snow cover does not persist, with the average temperature in the coldest month above -3C (27F). D Humid D climates are similar to C climates, with distinct summer and winter seasons, but D climates are colder. Winters are more severe, with persistent winter snow cover and an microthermal average temperature in the coldest month below -3C (27F). E Polar In E climates, winters are extremely cold and even the summers are cool, with the average temperature in the warmest month below 10C (50F). H Highlands H climates, found at latitudes worldwide, are determined by elevation above sea level. Temperature changes with altitude, ranging from about -18C (0F) to 10C (50F). Precipitation tends to decrease with altitude; windward sides of mountains usually receive more precipitation than leeward sides. 7  12/23/2024 What patterns do you notice? CC image courtesy Beck, H.E., Zimmermann, N. E., McVicar, T. R., Vergopolan, N., Berg, A., & Wood, E. F on Wikimedia Commons Köppen Classification System These graphs show temperature and precipitation for two different climates— a desert in Reno, Nevada, and a tropical rain forest in New Guinea. Copyright © McGraw-Hill Education Climate Classification 8  12/23/2024 Köppen Classification System Tropical climates Year-round high temperatures characterize tropical climates. In tropical wet climates, high temperatures are accompanied by up to 600 cm of rain each year. Tropical regions are almost continually under the influence of maritime tropical air. These areas have distinct dry winter seasons as a result of the occasional influx of dry continental air masses. Copyright © McGraw-Hill Education Climate Classification Köppen Classification System Dry climates Dry climates, which cover about 30 percent of Earth’s land area, make up the largest climatic zone. In these climates, continental tropical air dominates, precipitation is low, and vegetation is scarce. There are two subtypes of dry climates: arid regions, called deserts, and semiarid regions, called semideserts. Copyright © McGraw-Hill Education Climate Classification 9  12/23/2024 Köppen Classification System Mild climates Mild climates can be classified into three subtypes: humid subtropical climates, marine west-coast climates, and Mediterranean climates. The marine west-coast climates are dominated by the constant inland flow of air off the ocean. Copyright © McGraw-Hill Education Climate Classification Köppen Classification System Continental climates Continental climates are classified into three subtypes: warm summer climates, cool summer climates, and subarctic climates. These zones experience rapid and sometimes violent changes in weather, including severe thunderstorms or tornadoes. Copyright © McGraw-Hill Education Climate Classification 10  12/23/2024 Köppen Classification System Polar climates To the north of the subarctic climate lies one of the polar climates—the tundra. The tundra is known for its low temperatures. There are no trees in the tundra and precipitation is generally low. Copyright © McGraw-Hill Education Climate Classification Microclimates Heat islands Many concrete buildings and large expanses of asphalt can create a heat island, where the climate is warmer than in surrounding rural areas. Copyright © McGraw-Hill Education Climate Classification 11  12/23/2024 Graphing Climate Data A climatograph is a graphical representation Taiga Climatogram 30 of an area’s climate. 140 20 120 Precipitation (mm) Temperature (C) 10 100 80 0 60 -10 40 -20 The months of the year 20 0 -30 -40 are on the x axis, and J F M A M J J A S O N D Months temperature AND Precipitation (mm) Temperature (C) precipitation are on the y axis. In which month does the rainforest receive the most rainfall? Tropical Rainforest Climatogram 300 30 March 250 25 What do you notice Precipitation (mm) 200 20 Temperature (C) 150 15 about the temperature 100 10 in the tropical 50 5 rainforest? 0 0 J F M A M J Months J A S O N D The temperature does Precipitation (mm) Temperature (C) not fluctuate much throughout the year (they are located near the equator) 12  12/23/2024 In which month do grasslands receive the Grassland Climatogram 30 least rainfall? 140 January 25 120 Precipitation (mm) 100 20 Temperature (C) 80 15 60 10 During which season 40 5 are grasslands the 20 0 0 hottest? J F M A M J J A S O N D Months Summer Precipitation (mm) Temperature (C) (June – September) Long-Term Climatic Changes Ice ages The most recent ice age, as shown here by the extent of its glaciers, ended only about 10,000 years ago. Average global temperatures decreased by an estimated 5°C Copyright © McGraw-Hill Education Climatic Changes 13  12/23/2024 Short-Term Climatic Changes While an ice age may last for several million years, other climatic changes occur over much shorter time periods. Seasons are short-term periods of climatic change caused by regular variations in daylight, temperature, and weather patterns. Copyright © McGraw-Hill Education Climatic Changes Short-Term Climatic Changes El Niño Under normal conditions, trade winds and ocean currents move warm water west across the Pacific Ocean. Copyright © McGraw-Hill Education Climatic Changes 14  12/23/2024 Short-Term Climatic Changes El Niño During El Niño, warm water surges back toward South America, changing weather patterns. Copyright © McGraw-Hill Education Climatic Changes Natural Causes of Climatic Changes Solar activity The Maunder minimum is the term used to describe the period of low numbers of sunspots, from 1645 to 1716. This period closely corresponds to an unusually cold climatic episode called the Little Ice Age. Copyright © McGraw-Hill Education Climatic Changes 15  12/23/2024 Natural Causes of Climatic Changes Earth’s orbit Scientists hypothesize that a more elliptical orbit around the Sun could produce significant changes in Earth’s climate. Copyright © McGraw-Hill Education Climatic Changes Natural Causes of Climatic Changes Earth’s tilt If the angle of the tilt of Earth’s axis decreased, there would be less temperature contrast between summer and winter. Copyright © McGraw-Hill Education Climatic Changes 16  12/23/2024 Natural Causes of Climatic Changes Earth’s wobble Earth’s wobble determines the timing of the seasons. When the axis points toward the star Vega in 13,000 years, the northern hemisphere will experience summer during the time now associated with winter. Copyright © McGraw-Hill Education Climatic Changes Natural Causes of Climatic Changes Volcanic activity Climatic changes can also be triggered by the immense quantities of dust- sized particles, called aerosols, that are released into the atmosphere during major volcanic eruptions. Volcanic dust can remain suspended in the atmosphere for several years, blocking incoming solar radiation and thus lowering global temperatures. Copyright © McGraw-Hill Education Climatic Changes 17  12/23/2024 Influence on the Atmosphere The greenhouse effect The process of absorption and radiation of energy in the atmosphere results in the greenhouse effect—the natural heating of Earth’s surface caused by certain atmospheric gases called greenhouse gases. An increase in the amount of atmospheric greenhouse gases, particularly carbon dioxide and methane, would theoretically result in increased absorption of energy in the atmosphere. This can lead to a rise in global temperatures, known as global warming. Copyright © McGraw-Hill Education Impact of Human Activities Global Warming Burning fossil fuels One of the main sources of atmospheric carbon dioxide from humans is from the burning of fossil fuels including coal, oil, and natural gas. Burning fossil fuels also releases other greenhouse gases, such as methane and nitrous oxide, into the atmosphere. Copyright © McGraw-Hill Education Impact of Human Activities 18  12/23/2024 Global Warming Deforestation Deforestation—the mass removal of trees—also plays a role in increasing levels of atmospheric carbon dioxide. When trees are cut down, photosynthesis is reduced, and more carbon dioxide remains in the atmosphere. Copyright © McGraw-Hill Education Impact of Human Activities Global Warming Environmental efforts Individuals can reduce the amount of carbon dioxide emitted to the atmosphere by conserving energy, which reduces fossil fuel consumption. Copyright © McGraw-Hill Education Impact of Human Activities 19