Climate Vegetation and Ecosystems Physical Geography Climate and

Climate, Vegetation and Ecosystems Physical Geography: Climate and Vegetation Climate is created by the sun’s solar energy interacting with the earth’s land, water, and air. In turn, climate and soil shape the earth’s vegetation. 1

Section 1: Seasons and Weather - Seasons and weather occur because of the changing position of the earth in relation to the sun. - Weather extremes are related to location on earth. 2

Seasons Earth’s Tilt - Earth is tilted at a 23. 5˚ angle relative to the sun - Areas of Earth get more, less direct sun at different times of year - The seasons are related to the earth’s tilt and revolution - The solstice marks beginning of summer, winter - sun’s rays directly overhead at noon at furthest points north and south - The equinox marks the beginning of spring and autumn - day and night are equal in length 3

Weather and Climate - Weather—atmospheric conditions at a particular location and time - Climate—weather conditions at one location over long a period Example: Northern Russia has a cold climate - Atmosphere: the air and different types of gasses surrounding the earth - Temperature: a measure of warmth or coldness of an object or substance with reference to some standard value. 4

What Causes the Weather? - Sun: amount of solar energy received - Water vapor: determines whethere will be precipitation - Precipitation—water droplets falling as rain, snow, sleet, hail - Cloud cover: clouds may hold water vapor - Landforms and bodies of water - water heats slowly, loses heat slowly - land heats rapidly, loses heat rapidly - Elevation: as elevation increases, air becomes thinner - thin air cannot hold moisture - Air movement: distributes moisture and solar energy 5

Precipitation - Precipitation comes about when: - warm air rises, cools, loses ability to hold water vapor - water vapor condenses into droplets - water droplets form clouds - heavy clouds release droplets as rain, snow - Three types of precipitation - convectional - orthographic - frontal - Rain shadow—land on leeward side of hills, mountains - little precipitation in rain shadow 6

Hurricanes - Huge storms called hurricanes, or typhoons in Asia: - form over warm, tropical ocean waters - hit land with heavy rain, high winds, storm surge Tornadoes - Tornado—a powerful, funnel-shaped column of spiraling air: - born from strong thunderstorms - capable of immense damage 7

Weather Extremes Blizzards - Blizzard—heavy snowstorm with strong winds, reduced visibility Droughts - Drought: long period of time with either no or minimal rainfall Floods - Water spreads out over normally dry land 8

Section 2: Climate - Climate reflects the seasonal patterns of weather for a location over a long period of time. - Global climatic changes may be natural or human-made. Factors Affecting Climate Wind Currents - Wind, ocean currents help distribute sun’s heat worldwide - Convection—upward motion of air that transfers heat in atmosphere - Coriolis effect is the bending of winds due to Earth’s rotation 9

Ocean Currents - Resemble rivers flowing in the ocean - Warm water flows away from equator toward poles - Cold, polar water flows back toward equator Zones of Latitude - Low, or tropical latitude -hot all year round - Middle, or temperate latitude -warm summers and cold winters - High, or polar latitude -cold all year round 10

Elevation - Elevation is the distance above sea level - As elevation increases, climate gets colder Topography - Topography: landforms and their distribution in an area - Landforms, especially mountains, affect climate Changes in Climate El Niño - El Niño—winds push warm Pacific Ocean waters toward the Americas - La Nina—winds push warm waters toward Australia and Asia - Both cause natural, worldwide changes in climate 11

LA NIÑA What is La Niña? • La Niña is a phenomenon that describes cooler than normal ocean surface temperatures in the Eastern and Central Pacific Ocean; regions close to the equator off the west coast of South America. • In some parts of the world, La Niña causes increased rainfall while in other regions it causes extreme dry conditions. The conditions that cause La Niña recur every few years and can persist for as long as two years. • La Nina is considered to be the counterpart to El Nino, which is characterized by unusually warm ocean temperatures in the equatorial region of the Pacific Ocean. What Are The Effects of La Niña? • La Niña (small girl in Spanish) and El Niño (little boy still in Spanish) are known to have severe effects on atmospheric pressure, rainfall patterns and the global atmospheric circulation, Catastrophic Flood, food and agricultural produce shortage. 12

EL NIÑO • El Niño is a naturally occurring phenomenon that is linked to a periodic warming in sea surface temperatures • It typically occurs in December around Christmas. El Niño occurs every 2 -7 years, and can last anywhere between nine months and two years. What causes El Niño? • The tropical pacific has consistent westerly moving trade winds. The trade winds push warm water on the surface of the ocean from east to west (westerly). This causes the warm water to build up on the western side of the ocean near Asia. • DAMAGES • In general, El Niño causes vast amounts of rainfall in the eastern parts of the Pacific (the western coast of South America), and very dry weather on the western parts (India, Indonesia). 13

DIFFERENCE BETWEEN EL NIÑO & LA NIÑA La Niña has an effect on global weather, as well, and this effect is typically the opposite of El Niño, causing droughts in the eastern equatorial Pacific and floods in the western equatorial pacific. 14

Global Warming - Gradual warming of the earth’s atmosphere - Greenhouse effect—the earth warms due to trapped solar energy 15

Section 3: World Climate Regions - Temperature and precipitation define climate regions. - Broad climate definitions help to identify variations in weather at a location over the course of a year. 16

Defining a Climate Region Typical Weather - Temperature and precipitation define climate - Location, topography, elevation may impact climate - Five general climate regions: - tropical (low-latitude) - dry - mid-latitude - highland 17

Types of Climates Tropical Wet - Always hot; daily rainfall adds up to more than 80” annually Tropical Wet and Dry - Warm, wet summer season; cooler, dry winter season Semiarid - Hot summers; mild to cold winters; little precipitation Desert - Two kinds of desert—hot, cool/cold; less than 10” rain per year 18

Mediterranean - Summers dry and hot; winters cool and rainy Marine West Coast - Moderate temperatures; frequently cloudy, foggy, damp Humid Subtropical - Long periods of summer heat and humidity; winters mild to cool Humid Continental - Great variety of temperature, precipitation; four distinct seasons 19

Subarctic - Summers are short and cool; winters are long and very cold Tundra - Tundra—flat, treeless ring of lands around the Arctic Ocean - Very little precipitation; summer temperatures around 40˚ F. - Permafrost is the constantly frozen subsoil found in this region Ice Cap • Snow, ice, permanently freezing temperatures Highlands - Climate varies with latitude, elevation, topography, location 20

Section 4: Soils and Vegetation - Soil and climate help to determine the vegetation of a region. - Human land use alters the vegetation in both positive and negative ways. 21

Soil Regions Shaping Human Existence - Soil is a thin layer of weathered rock, humus, air, water - Topsoil refers to the top 6” of soil - Soil characteristics vary with climate - Type of soil determines type of vegetation that can be supported - Type of vegetation determines type of possible human activity 22

Vegetation Regions Natural Environments - Ecosystem—interdependent community of plants and animals - Biome—the ecosystem of a region - Biomes are further divided into: - forest - grassland - desert - tundra 23

Forestlands - Chaparral: a dense growth of shrubs or small trees - Forest regions categorized by trees they support—broadleaf or needle - Deciduous—broadleaf trees: maple, oak, birch, cottonwood - mostly in Northern Hemisphere - Tropical Rain forest—tropical forest covered with broadleaf trees - Coniferous—needle leaf trees; cone bearing: pine, fir, cedar - mostly in Northern Hemisphere - Deciduous and coniferous trees together form mixed forest 24

Grasslands - Flat regions with few trees - Temperate Grassland: grasslands found in temperate zones - A savanna is a tropical grassland - Steppe, or prairie, are temperate grasslands of Northern Hemisphere 25

Desert and Tundra - Plants in these regions have adapted to climate extremes: - tundra plants (mosses, lichen) hug the ground - desert plants (cacti, sagebrush) conserve water, withstand heat - Desertification: the process by which an area becomes a desert - Oasis: a small fertile or green area in a desert region, usually having a spring or well 26

Human Impact on the Environment Altering the Landscape - Humans either adapt to land, or alter it to meet their needs - Some human activities that affect the environment: - building dams - installing irrigation systems - Agriculture: the science of cultivating the land - Acid Rain: precipitation, as rain, snow, or sleet, containing relatively high concentrations of acid-forming chemicals - Deforestation: to clear of forests or trees - Technology: “the branch of knowledge that deals with the creation and use of technical means and their interrelation with life, society, and the environment. ” (dictionary. com, August 2012) 27

Bibliography • Mcdougal Littell, World Geography. Houghton Mifflin Company. August, 2012. • Dictionary. com. August, 2012. 28