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Sit with your Group for G-3 Topic #11 Systems & Feedbacks

Thursday Oct 21st. Sit with your Group for G-3 Topic #11 Systems & Feedbacks. ANNOUNCEMENTS RQ-5 was due today 30 minutes before class begins. RQ-6 is due NEXT Thursday – will be posted Friday.

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Sit with your Group for G-3 Topic #11 Systems & Feedbacks

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  1. Thursday Oct 21st Sit with your Group for G-3 Topic #11 Systems & Feedbacks • ANNOUNCEMENTS • RQ-5 was due today 30 minutes before class begins. RQ-6 is due NEXT Thursday – will be posted Friday. • ASSIGNMENT I-3 is due IN CLASS next Tuesday. The directions are posted in D2L. Please bring your worksheet to class ALREADY STAPLED! • The EXAMS are being graded this week. You should have them back early next week.

  2. G-3 ASSIGNMENT (5 pts) Applying the Energy Balance Terms Your task is to decide which component or componentsworking togetherare most directly related to or responsible forthe observed phenomenon. # 1 – #12 : Left side of equation # 13 - #15: Right side of equation p 53

  3. 1. blue skies 2. Sunglasses while skiing 3. Bright even though cloudy

  4. 4. More intense solar radiation (tan /skin damage, etc.) at noon vs. dawn or dusk Sun directly overhead DAWN or DUSK Sun just above horizon NOON Solar rays perpendicular to body Solar rays perpendicular to body 5. The Greenhouse Effect 

  5. To illustrate the GREENHOUSE EFFECT: SUN SUN SUN EARTH EARTH Greenhouse effect EARTH A B C B is better than the others . . . But only the circled part represents the GH Effect!! . . . 

  6. 6. Red sunsets 7. Infrared cameras / “night vision” 8. “Tennis whites” tradition

  7. 9. Shadow on sunny day 10. Rainbow 11. Black streaks 12. Parking on blacktop

  8. 13. Hot air balloon 14. Pigs cooling off in the mud 15. Evaporative coolers work best in the desert

  9. TIME TO WRAP UP FOR TODAY! G-3 ASSIGNMENT (5 pts)(cont.) Applying the Energy Balance Terms Don’t forget to SIGN IN with the #’s you wrote up!

  10. THE ANSWERS

  11. 5. + together = the Greenhouse Effect 3. 2. 1. gases of atmosphere scatter shorter blue wavelengths 4. Noon: more dusk: more The LEFT side of the equation:

  12. 6. (dust, thicker atmosphere scatters longer red/orange wavelengths) 7. radiates day & night; camera senses IR 9. leads to distinct shadows, while diffuse SW radiation does not 8.

  13. 10. All visible wavelengths scattered & transmitted in a colored spectrum by raindrops 12. More is absorbed, leads to more which can then warm up car 11. Attempt to increase absorption & reduce into eyes; reduces glare

  14. H LE 14. Wet mud evaporates from pig & cools him: Heat from pig’s body is conducted into soil: 13. Hot air (less dense than surrounding cool air) rises in a convection current & lifts balloon G 15. June is dryer, hence air can hold more water vapor, more evaporation occurs, hence more energy goes into instead of LE H The RIGHT Side of the Equation:

  15. SOME APPLICATIONS OF THE ENERGY BALANCE IN DIFFERENT PARTS OF THE GLOBE: http://www.earthweek.com/ 

  16. GLOBAL CHANGE in the News! Warmer-than-average conditions dominated the world’s land areas. The most prominent warmth was in western Alaska, most of the contiguous United States, eastern Canada, Greenland, the Middle East, eastern and central Europe, western and far eastern Russia and northeastern Asia. Cooler-than-average regions included much of Australia, western Canada, parts of the northern United States, parts of western and central Europe, and central Russia. This year also marked the 14th consecutive September with below-average Arctic sea ice extent. Antarctic sea ice reached its annual maximum in September. September 2010 was the third largest sea ice extent on record (2.3 percent above average), behind 2006 (largest) and 2007 (second largest).

  17. http://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.phphttp://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.php http://nsidc.org/data/seaice_index/index.html

  18. This summer marks the fourth consecutive year--and fourth time in recorded history--that the fabled passage has opened for navigation. Over the past four days, warm temperatures and southerly winds over Siberia have also led to intermittent opening of the Northeast Passage, the shipping route along the north coast of Russia through the Arctic Ocean. It is now possible to completely circumnavigate the Arctic Ocean in ice-free waters, and this will probably be the case for at least a month. This year marks the third consecutive year--and the third time in recorded history--that both the Northwest Passage and Northeast Passage have melted free, according to the National Snow and Ice Data Center. The Northeast Passage opened for the first time in recorded history in 2005, and the Northwest Passage in 2007. It now appears that the opening of one or both of these northern passages is the new norm, and business interests are taking note--commercial shipping in the Arctic is on the increase, and there is increasing interest in oil drilling. The great polar explorers of past centuries would be astounded at how the Arctic has changed in the 21st century. http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1589 Antarctic vs Arctic . . . http://nsidc.org/seaice/characteristics/difference.html

  19. http://climateprogress.org/2010/08/28/arctic-sea-ice-volume-northwest-passage-david-barber-antarctic-sea-ice/http://climateprogress.org/2010/08/28/arctic-sea-ice-volume-northwest-passage-david-barber-antarctic-sea-ice/

  20. TOPIC # 11 Introduction to Models: UNDERSTANDING SYSTEMS &FEEDBACKS Class notes pp 55-61

  21. “When one tugs at a single thing in nature, one finds it attached to the rest of the world.” ~ John Muir p 73

  22. SYMBOLIC NOTATION • use of a picture or diagraminstead of words • abbreviation, symbol, or acronym instead of spelling out the whole word or concept: • NATS 101-GC • $ % & + - = x or * • IPCC p 55

  23. SYMBOLIC NOTATION (cont) NUMBERS!! 1, 2, 8 3.8 x 10 - 4 Elements and molecules: H, He, H2O CO2 Formulas & Equations y = a + bx (equation for a straight line) p 55

  24. SYMBOLIC NOTATION (cont)MODELS! • WHAT IS A MODEL? • a representation of something (usually miniature or not to scale) • an example for imitation or emulation • a person or thing that serves as a pattern • an analogy or analogue of something p 55

  25. WHAT IS A MODEL? • "a description or analogy to help visualize something that cannot be directly observed" • or "a system of postulates, data, and inferences presented as a mathematical description of an entity or state of affairs" Note the word “system” p 55

  26. WHAT IS A SYSTEM? • SYSTEM = a set of interacting components • SYSTEM MODEL = • a set of assumptions, rules, data and inferences that define the interactions among the components of a system and the significant interactions between the system and the “universe” outside the system p 55

  27. SYSTEM DIAGRAM = A diagram of a system that uses graphic symbols or icons to represent components in a depiction of how the system works p 55

  28. One example of a system diagram for a model used in global change studies: 

  29. Another more complicated system diagram:

  30. COMPONENT Component(def) = An individual part of a system. A component may be a reservoir of matter or energy, a system attribute, or a subsystem. p 55

  31. COUPLING Coupling (def): The links between any two components of a system. Couplings can be positive (+) or negative (-) p 55

  32. A coupling between an electric blanket temperature component and a body temperature component: + If the electric blanket’s temperature INCREASES . . . The person’s body temperature will also INCREASE Q1: What type of COUPLING IS THIS? 1) Positive + 2) Negative - p 55

  33. A coupling between a person’s body temperature and an electric blanket’s temperature - The electric blanket’s temperature control will be turned down and the blanket temperature will DECREASE If the person’s body temperature INCREASES and he gets too hot . . . Q2: What type of COUPLING IS THIS? 1) Positive + 2) Negative - p 55

  34. THE “RULE” – how to tell if it’s a positive or negative coupling: Positive couplings have a solid “arrow” with a normal arrowhead pointing in the direction of the coupling: Negative couplings have an “open circle” arrowhead pointing in the direction of the coupling:

  35. FEEDBACKS Feedback mechanism (def): a sequence of interactions in which the final interaction influences the original one. Feedbacks occur in loops p 56

  36. Feedback Loop(def) = A linkage of two or more system components that forms a ROUND-TRIP flow of information. Feedback loops can be positive (+) or negative (-). p 56

  37. A positive feedback is an interaction that amplifies the response of the system in which it is incorporated (self-enhancing; amplifying). p 56

  38. A negative feedback is an interaction that reduces or dampens the response of the system in which it is incorporated (self-regulating; diminishes the effect of perturbations)) p 56

  39. One way to remember the effect that a NEGATIVE feedback loop has is to think of the word "negligible" i.e., a perturbation or disturbance in a system characterized by a negative feedback loop will be able to adjust to the perturbation and ultimately the effect on the system will be negligible

  40. FEEDBACK LOOP Q3: What kind of FEEDBACK LOOP IS IT? 1) Positive (+) 2) Negative (-) ??? - p 56

  41. THE “RULE” – how to tell if it’s a positive or negative feedback LOOP: Count the # of number of NEGATIVE COUPLINGS: If there is an ODD # of negative Couplings, the loop is NEGATIVE: If there is an EVEN # of negative couplings, the loop is POSITIVE

  42. One more term: EQUILIBRIUM STATE = a state in which a system is in equilibriumstated another way: = the state in which the system will remainunless something disturbs it.) An equilibrium state can be:stable or unstable. Take notes

  43. The presence of FEEDBACK LOOPS leads to the establishment of EQUILIBRIUM STATES: • Negative feedback loops establish STABLE equilibrium states • NEGATIVE LOOP  STABLE EQUILIBRIUM • [recall negative feedback = “self regulating”] • STABLE EQUILIBRIUM STATES: • are resistant to a range of perturbations • (i.e., system responds to modest perturbations by returning to the stable equilibrium state) Take notes

  44. A negative feedback loop(can also be described as) a STABLE EQUILIBRIUM STATE : response that tends to return the system to its equilibrium state A modest disturbance (short-term perturbation) Take notes See top figure on p 59

  45. A LARGE or more persistent disturbance (a forcing) can carry the system to a different equilibrium state (so there area some limits to stability, even in a stable state!) p 59

  46. Everyday life example: Proper alignment of dual control electric blanket: p 56

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