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IB Student Picnic. Wednesday, tomorrow!, 5-8 pm Illini Grove Pavilion (corner of Lincoln and Pennsylvania Ave.) Meet Faculty Free Food Free T-shirt Find out what SIB is all about and meet other IB majors!! Email dlanter@illinois.edu or 333-3044 **Rain Location: 3 rd floor Levis**
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IB Student Picnic Wednesday, tomorrow!, 5-8 pm Illini Grove Pavilion (corner of Lincoln and Pennsylvania Ave.) Meet Faculty Free Food Free T-shirt Find out what SIB is all about and meet other IB majors!! Email dlanter@illinois.edu or 333-3044 **Rain Location: 3rd floor Levis** (912 W Illinois)
Next lecture: Humans, Climate Change, and Ecological Responses
Assignment Responses to Climate Change: Lecture Outline: print, read, bring… Learn… 1) 5 major concepts 2) 6 levels of ecological organization (see 1.1 also) 3) contrast acclimation vs adaptation Pg. 146-7 in text Midwest Climate
OBJECTIVES: What creates variation in climate and how does it explain the diversity and distribution of biomes? • Build a model for proximal causes of global variation in climate and biomes • How do features of the earth contribute to climatic variation? • What are causes of temporal changes in climate and biomes? • What are local effects on climate?
***PRE-TEST: What feature of the earth causes: 1) Daily rhythm of dark and light? 2) Temperature warmer at 0º than 90 º? 3) Seasonal change in climate? 4) Less variation in temperature in N than S? 5) Winds to be diverted from N-S direction? Rotates on axis B) Round C) Tilt of 23º on axis D) Rotates around sun E) More land mass in N than S
Answers: 1) Daily rhythm of dark and light? = A 2) Temperature warmer at 0º than 90 º? = B 3) Seasonal change in climate? = C + D 4) Less variation in temperature in N than S? = E 5) Winds to be diverted from N-S direction? = A + B • Rotates on axis B) Round C) Tilt of 23º on axis D) Rotates around sun E) More land mass in N than S
Overall conceptual model: Solar radiation temperature wind and ocean currents precipitation
***What accounts for differences in range of temperatures in N vs S hemisphere? N.B. Specific heat is higher for water than land.
***What causes seasons and temporal variation in temperature?
Variation in temperature generates winds.(N.B. Mirrror of S and N hemispheres) Winds drive ocean currents and redistribute heat and moisture.
***What are latitudes of tropical rainforests and deserts? Why?
Why is it wet at 0° and dry at 30°?Hadley cells and ITCZ (inter-tropical convergence zone):
Solar equator (ITCZ) moves seasonally. (so do belts of temp., wind, and rain)---> causes seasonal variation in climate.
What causes deflections in air flow from N-S? Coreolis effect ; affects oceans too!
Ocean currents 1) differ in N and S, 2) redistribute heat and moisture and 3) affect marine environment on global scale climates on land. clockwise counter- clockwise upwelling
Upwelling currents bring cold, nutrient-rich water to the surface --->support high productivity.
***Why are (most) deserts on W side of continents? What causes the Gobi desert in central Asia?Why does England have temperature deciduous forest rather than boreal forest?
Overall conceptual model: Solar radiation temperature wind and ocean currents precipitation
***What factors have changed existence and location of biomes through time? • Continental drift • Mountain building and rain shadows • Changes in orbit, tilt, wobble of earth • Climate variation • past climate change • present climate change • Human alteration in land cover
Changes in biomes through geological time…
El Nino vs. El Nina: note recent increase in stength + frequency of El Nino
El Nino years bring drought and fire to tropical peat forests in SE Asia
Negative impact of El Nino on crops In far-flung places
***What determines local climate? • 1) Proximity to bodies of water • Continentalclimates in interiors More arid More variable • Maritime climates on coasts Less arid Less variable
2) Topography: gradients in mountains • Air cools as rises---> temp. decrease-->vegetation changes • (6-10°C drop for every 1000 m in elevation)
Why do mountains cause a rainshadow on their leeward side? How do they affect biomes? How do mountain and wind directions affect this?
***Topographysuperimposes local variation on general climatic patterns. What causes these vegetation patterns?
Higher temperatures on S than N-facing slopes; >T --> > evaporation + < soil moisture
OBJECTIVE: What creates variation in climate and how does it explain the diversity and distribution of biomes? • Build a model for proximal causes of global variation in climate and biomes • What features of the earth contribute to climatic variation? • What are causes of temporal changes in climate and biomes? • What are local effects on climate?