Climate Notes PDF

Climate: Why organisms live where they do Biogeographic realms (ecozones) 1 News of the Day meet the Pumpkin toadlet 2 The picture can't be displayed. Tiny toad, tiny ears, tiny semi-circular canals 3...

Climate: Why organisms live where they do Biogeographic realms (ecozones) 1 News of the Day meet the Pumpkin toadlet 2 The picture can't be displayed. Tiny toad, tiny ears, tiny semi-circular canals 3 1 4 5 The need to know: Overview: understand how climate is generated, and how and why it is changing Key concepts: understand and be able to describe -- coriolis forces, the ITCZ, Hadley cells, drivers of regional climate, the difference between climate and weather, greenhouse gases and the greenhouse effect, anthropogenic global warming. 6 2 Physical factors drive the distribution of organisms at the global scale 1. light 2. temperature Climate 3. precipitation 7 What drives global climate? 8 Global climate is driven by: Ø sunlight, particularly to the tropics Ø movement of the planet Ø atmospheric and ocean circulation 9 3 10 Tilt on the earth’s axis generates seasonality in N and S Hemispheres Winter solstice: shortest day Summer solstice: longest day 11 Sunlight is more intense at tropical latitudes… Oblique angle More atmosphere less energy/m2 Steep angle Less atmosphere more energy/m2 12 4  …causing air to rise and cool… equator 13 What happens to the water in air as air cools? 14 As air rises and cools it loses moisture…so it rains a lot 15 5  Air moving upward at equator creates Inter- tropical Convergence Zone (ITCZ) low pressure 30 degrees N EQUATOR 30 degrees S 16 17 Dry, cold air is dense -- so begins to fall, picking up moisture… 18 6 19 Formation of “Hadley cells” 20 So how are prevailing winds that blow east and west generated? 21 7  The Coriolis Force Gaspard Coriolis 22 The Coriolis Force Gaspard Coriolis looking down from above north pole looking straight from side 23 Trade winds form because the earth is spherical Direction of earth’s spin https://www.youtube.com/watch?v=WB4dxpUS530 24 8 25 You know you love that Learning Catalytics 26 A cosmic catastrophe jolts Earth so that its axis is perpendicular to the orbital plane between Earth and the sun. The LARGEST effect of this change would be A. Elimination of tides B. Increase in length of night at equator C. Decreased temperature at equator D. Elimination of seasonal variation 27 9  These forces also affect Ocean circulation At ocean surface, large-scale gyres are driven by winds and coriolis forces shallow currents driven by prevailing winds 28 GLOBAL CLIMATE is modified to produce regional climate by: 1. landmasses (heat faster than oceans) monsoons land-sea breeze 29 global climate is modified to produce regional climate by: 2. mountain ranges deflect winds produce rain gradients windward leeward 30 10  global climate is modified to produce regional climate by: 3. ocean (moderates temp and rainfall) Gulf Stream current off coastal FL keeps us WARM and WET! (we are at 29.6º latitude) 31 So, all of that was big-scale climate stuff, but there’s also “microclimate” Ø A local zone where the climate differs from the surrounding area 32 Global Climate Change 33 11  What’s the difference between climate and weather? 34 Weather is the day-to-day state of the atmosphere, and its short-term variation in minutes to weeks. Climate is how the atmosphere behaves over a relatively long period of time. 35 Get your learning catalytics on 36 12  Which statement below is an example of climate? A. The high for today in Gainesville, FL will be 66°F. B. The average temperature in Gainesville during the month of July, calculated between 1981- 2010, is 91°F. C. On January 28, 2014, Pensacola, FL received 1.8 inches of snow. D. Penguins 37 18 of 19 hottest years in recorded history since 2001 38 So why is our climate getting warmer? 39 13  “Greenhouse gases” on the rise What’s a greenhouse gas? A gas that absorbs and emits infrared radiation, but not radiation in or near the visible spectrum Water CO2 Methane N2O (nitrous oxide) O3 (ozone) CFCs (chlorofluorocarbons) 40 Greenhouse gases on the rise 41 The “greenhouse effect” atmosphere pre-1760s atmosphere in 2023. h ig h e r le v e l o f g re e n h o u s e g a s e s lo w e r le v e l o f g re e n h o u s e g a s e s 42 14  Who’s doing the emitting? 43 A good greenhouse effect video can be found at the link below: Ø https://www.youtube.com/watch?v=fYq dKiT0Eqo&list=PL- Y2w0ZA2YiozYqwteRV3InKrCfv6l90v&i ndex=4 44 Impacts and feedbacks We’ve raised average temps by 0.8 Celsius increase in extreme weather events 1/3 summer sea ice in Arctic is gone influences earth’s “albedo” starving polar bears Oceans are 30% more acidic affects organisms that have calcified shells Atmosphere over ocean is 5% wetter Warmer ocean causing massive coral bleaching 45 15  **K !! 46 Any good news? Enough raw energy reaches the Earth from the sun in one hour to equal all of the energy used by the entire world in a full year. The cost of electricity from solar cells is now equal to or less than the cost of electricity from other sources in at least 79 countries 47 What can I do? Bike or walk Be energy efficient Eat one meat-free meal a day Compost and recycle Eat locally grown, organic food 48 16  Final LC question If the direction of the earth’s spin were reversed, what would happen to the direction of the tradewinds? a. No change b. They would blow from east to west c. They would blow from west to east d. They would change, but the direction is impossible to predict. 49 Have a great weekend! 50 17