Chapter 6 Climate Terrestrial Biodiversity and Aquatic Biodiversity

Chapter 6. Climate, Terrestrial Biodiversity, and Aquatic Biodiversity Section 6 -1 Weather and Climate: A Brief Introduction

What is weather? Short-term set of physical properties of the troposphere at a particular place and time. üTemperature üPressure üHumidity üPrecipitation üSunshine üCloud cover

What is weather? • Meteorologists use equipment to obtain data on weather variables: – Atmospheric pressure – Precipitation – Temperatures – Wind speeds locations of air masses and fronts This data is fed into computer models to draw weather maps to forecast the weather

What is Climate? • Climate is a region’s general pattern of atmospheric of weather conditions over a LONG period of time – Average temperature and average precipitation are the two main factors that determine a region’s climate

Climate is Climate the average weather patterns for an area over a long period of time (30 - 1, 000 years). and It is determined by its Average Precipitation effects and Average Temperature which are influenced by latitude altitude ocean currents and affects where people live how people live what they grow and eat

5 factors that determine global air circulation patterns 1. 2. 3. 4. 5. Uneven heating of Earth Seasons Earth’s rotation Variation of sun’s output Properties of air and water

1. Uneven Heating of the Earth

Cold Cool Temperate Warm Temperate Tropical (equator) Tropical Warm Temperate Cool Temperate Cold Climate type

2. Seasons

3. Rotation of Earth

4. Variations in solar output

5. Properties air and of • of 5. Properties air and water – Convection Cells – circulate air, heat, and moisture both vertically and from place to place.

How do ocean currents affect regional climates? • The five factors PLUS differences in water density create warm and cold ocean currents. • These currents (driven by winds and earth’s rotation) redistribute heat and therefore influence climate and vegetation – If ocean’s currents suddenly stopped flowing, there would be deserts in the tropics and thick ice over northern Europe, Siberia, and Canada – Currents also mix ocean waters and distribute nutrients and dissolved oxygen needed by aquatic organisms

60, 000 Nikes spilled into the Pacific

Polar (ice) Warm temperate Highland Warm ocean current Subarctic (snow) Dry Major upwelling zones Cold ocean current Cool temperate Tropical River CD ani 2

Solar radiation Convection cell Cool Warm current Cool current air Equator Warm air Warm water Warm current Polar front Cool current Surface Currents Midlevel currents Bottom Currents Cold water Ocean Currents

Movement of surface water Wind Diving birds Fish Upwelling Zooplankton Phytoplankton Nutrients Upwellings – winds push surface water away from the land, this water is replaced by cold-nutrient rich bottom water – brings deep cool water to the surface

Cold, dry air falls Cell 3 North Polar cap Arctic tundra Evergreen coniferous forest 60° Temperate deciduous forest and grassland Desert 30° Tropical deciduous forest 0° Equator Cell 2 North Cool, dry air falls Cell 1 North Tropical rain forest Tropical deciduous forest 30° 60° Cell 1 South Desert Temperate deciduous forest and grassland Cool, dry air falls Cell 2 South Polar cap Cold, dry air falls Relationship between global air circulation and biomes Moist air rises — rain Cell 3 South Moist air rises, cools, and releases moisture as rain

El Nino - “The Christ Child” El Niño is a disruption of the oceanatmosphere system in the Tropical Pacific having important consequences for weather and climate around the globe.

What is the El Nino-Southern Oscillation (ENSO)? 1) Occurs in the Pacific Ocean 2) Prevailing westerly winds weaken or cease 3) Surface water along the South and North America coasts become warmer 4) The normal upwelling of cold, nutrient rich water are suppressed Bad fishing

Surface winds blow westward EQUATOR AUSTRALIA Warm waters pushed westward SOUTH AMERICA Warm water Thermocline Cold water Normal Conditions

Winds weaken, causing updrafts and storms Drought in Australia and Southeast Asia EQUATOR AUSTRALIA Warm water flow stopped or reversed SOUTH AMERICA Warm water deepens off South America Warm water Thermocline Cold water El Niño Conditions

El Niño Drought Unusually high rainfall Unusually warm periods

La Nina • Cooling counterpart of El Nino • Means more Atlantic hurricanes, colder winters in Canada and northeastern US, warmer and drier winters in the southeastern and southwestern US and more wildfires in Florida

How does the chemical makeup of the atmosphere lead to the greenhouse effect?

The Greenhouse Effect Major Greenhouse Gases 1) 2) 3) 4) 5) Water vapor H 2 O Carbon dioxide CO 2 Methane CH 4 Nitrous oxide N 2 O Chlorofluorocarbons CFCs

Are Greenhouse Gases GOOD or BAD? • THEY’RE BOTH • GOOD - without greenhouse gases, the Earth would be too cold for life • BAD - too many greenhouse gases may lead to global warming

Where do greenhouse gases come from? • ALL OF US!!! • Burning fossil fuels releases: – CO 2 – H 2 O – N 2 O • Cows release methane (CH 4) • Various refrigerants use CFCs

How does the chemical makeup of the atmosphere create the ozone layer? Is this what the hole in the ozone layer looks like?

Did Mrs. Gallo destroy the OZONE… it’s possible…

Ozone • In a nutshell – we will discuss in detail later in the year – In stratosphere oxygen (O 2) is converted to ozone (O 3) and back to oxygen by a sequence of reactions initiated by UV radiation from the sun – Results in a thin veil protecting us from 95% of sun’s harmful UV radiation – Evidence indicates that chemicals added to atmosphere by our activities are decreasing the level of protection – Thermal cap – warm layer of air created by ozone layer that prevent churning gases in the troposphere from entering the stratosphere, important in determining average temp of troposphere and climate

Microclimates – local climatic conditions that differ from the general climate of a region a Winds carry moisture inland from Pacific Ocean b Clouds, rain on windward side of mountain range c Rain shadow on leeward side of mountain range Dry habitats Moist habitats Rain Shadow Effect - lower precipitation and semiarid or arid conditions on the leeward side of a mountain-

Rain Shadow Effect

Cool air descends Land warmer than sea; breeze flows onshore Sea Breeze Warm air ascends

Cool air descends Warm air ascends Land cooler than sea; breeze flows offshore Land Breeze

Weather Extremes • Tornadoes • Tropical cyclones ØAtlantic Ocean = hurricanes ØPacific Ocean = typhoons

Descending cool air Severe thunderstorm Tornado forms when cool downdraft and warm updraft of air meet and interact Severe thunderstorms can trigger a number of smaller tornadoes Rising warm air Rising updraft of air

Tropical Cyclones Rising winds exit from the storm at high altitudes. The calm central eye usually is about 24 kilometers (15 miles) wide. Gales circle the eye at speeds of up to 320 kilometers (200 miles) per hour. Moist surface winds spiral in towards the center of the storm

Hurricane Sandy FRANKENSTORM • Hurricane Sandy was the largest Atlantic hurricane on record • The second-costliest Atlantic hurricane in history, only surpassed by Hurricane Katrina in 2005 • Hurricane - A hurricane is a tropical storm with winds that have reached a constant speed of 74 miles per hour or more. The eye of a storm is usually 20 -30 miles wide and may extend over 400 miles. The dangers of a storm include torrential rains, high winds and storm surges. A hurricane can last for 2 weeks or more over open water and can run a path across the entire length of the Eastern Seaboard • Video – Weather Channel

Prince William Sound Gulf of Alaska Risk of Tornadoes Highest High Medium Low CANADA UNITED STATES Grand Banks Tropical Cyclone Frequency High Moderately high MEXICO Atlantic Ocean