1. WATER

2. Biologically Important Things About Water

3. 9 Major Physical Characteristics  Cohesion and Surface Tension  High Latent Heats of Vaporization and Fusion  High Heat Capacity  Good Solvent  Viscosity  Less compressible than air  Less dense as a solid than as a very cold liquid  Can hold dissolved gases  Differentially absorbs light wavelengths

4. Most of these characteristics (the first 5) are based on the fact that water is a polar molecule

5. The Mickey Mouse Molecule

6. The Water Molecule Covalent bond Electron ___ + + Hydrogen bond The Mickey Mouse Molecule

7.  An Atom is made up of three parts  The Proton (+ positively charged)  The Neutron (no charge)  The proton and neutron make up the nucleus  The Electrons (Negatively Charged)  Bonds form when atoms share electrons

8. What does polarity mean?  The hydrogen atoms are pulled back (form Mickey’s ears)  This makes the ears slightly positive because the Oxygen molecule has taken the electrons (-) leaving the protons (+)  The head is slightly negative because it has taken on the electrons Magnets are polar because one end (pole) is positive and the other end (pole) is negative

9. Lets Look at Mickey again

10. Water molecules are polar

11. Their polarity allows ______to form

12. Cohesion  means water molecules stick together  This causes ______ _______ ______ _______

13. Surface Tension  Water molecules stick together to form a “skin” So…?  Some creatures use this air-water interface as a niche (e.g. Glaucus)  Wind can impart ______to water to form _______

14. Physalia and Glaucus  Due to surface tension he can float on water and eat jellyfish and Man ‘o wars

15. Adhesion  Water attracted to other materials  This is why you have to read the ________n a Graduated Cylinder.

16. Viscosity  The fluid nature of water  Internal friction of water molecules  Increases with decreasing____________ So…? Planktonic organisms in warm, less viscous water have different characteristics than those in cold water

17. Incompressibilty  Water is extremely less compressible than air ( you can’t squeeze water that much) So…? Organisms in the deep have a higher _______content in their tissues than similar organisms at the surface

19. Heat Capacity  Ability to gain or lose a large amount of heat without ___________ ____________  Added energy used to break H bonds – in other substances, that E increases molecular motion and temperature

20. Heat Capacity So…?  Allows currents to pick up heat and transfer it around the planet  Moderates coastal climates That’s why San Francisco is wamer than us now and the news always talks about snow north and west of the city

21. Latent Heat of Vaporization  Amount of heat energy required to change 1 gram of water to ________(or amount of energy removed to change from steam to water)  Is very high for water: 540 cal/g

22. Latent Heat of Fusion  Amount of heat energy required to change 1 gram of ice to water (or the amount of energy taken out to change water to ice)  Very high for water: __________

23. Latent Heat So…?  If the latent heat of vaporization was lower – the water on the planet would all evaporate at ________ temperatures  If the latent heat of fusion was lower –the water on the planet would all freeze at ambient temperatures  The energy assoc. with L.H. of Vap. drives the world weather system

24. States of Water

25. Adding Heat a b c d e Latent Heat of fusion Latent Heat of Vaporization Increasing amount of added heat  Increasing temperature 

26.  Water crystallizes, salts left behind  A progression from ice crystals > pancakes > floes > sheets –Icebergs are _________– The Salt is squeezed out

27. pancake ice (broken up crusts of ice crystals) ice bergs Floes thicker

28. Pancakes-Floes - thickening

29. Floes – with pressure ridges

30. Floes – and leads

31. Floes – anchored to the land = fast ice

32. Shackleton – 1915-1916, stuck in the ice floes

33. Water’s polarity makes it a good solvent Dissolving a salt molecule into sodium and chloride ions

34. Water is less dense as a solid than as a very cold liquid  Max. density of any phase of water is 4 degrees C (so very cold liquid has highest density)  Less dense ice floats on more dense water  Freshwater floats on top of Seawater. Why? Seawater has Sodium chloride and other minerals to make it more dense than freshwater.

35. Density and Life So…?  Organisms aren’t crushed by sinking ice in the winter

37. Water holds dissolved gases  Dissolved oxygen (dO) - made as by-product of ____________ - marine organisms are adapted to pull dO out of water ---Ex. Gills - colder water holds more dO - oxygen minimum layer occurs where oxygenconsumption is _____and production is _______

38. Oxygen levels in a vertical column of water More Producers than consumers Surface Layer Intermediate Layer Deep Layer More Consumers Than Producers

39. CO 2 Origin and Function  Carbon dioxide (CO 2 ) -made as a by-product of respiration -oceans act as a carbon sink – absorbing excess CO 2 from the atmosphere absorbing excess CO 2 from the atmosphere -required for photosynthesis -buffering reaction based on CO 2 keeps ocean pH stable

40. Buffering Action of CO 2 Just Know----This just means the CO 2 will help keep the pH level in the ocean stable Just Know----This just means the CO 2 will help keep the pH level in the ocean stable Here is the formula but you don’t need it know it Here is the formula but you don’t need it know it CO 2 + HOH  H 2 CO 3 H 2 CO 3  H + + HCO 3 - HCO 3 -  2H + + CO 3 2-

42. Light in the Oceans  Red Light penetrates the least  Blue light penetrates the deepest So…? Color trends of organisms change with depth which means….. which means….. Why be a color no one can see? Why be a color no one can see?

43. Chemical and Physical Structure of the Oceans  Light transmission affects life both directly and indirectly.  Most light is absorbed within the top 1 meter of the ocean; this contributes to the warming of the surface layer.  Light changes with depth. –Photic and aphotic zones

44. Light in the ocean Photic Zone- Surface down 100 M depth. Area Where there is Enough light for ____________to occur Aphotic Zone- below 100 meters Not enough light for photosynthesis

45. V I B G Y O R

46. Light absorption in the open ocean. Shorter wavelengths = UV Longer wavelengths = infrared

47. Violet Oceans  If our sun radiate more visable violet light we would have Violet colored oceans we would have Violet colored oceans

55. The color of the ocean  Tropical oceanic waters tend to be blue because in clear water blue wavelengths are least absorbed and red wavelengths are strongly absorbed. The blue light is what is left for you to see.

56. The color of the ocean  Coastal waters at mid and high latitudes tend to appear green. This is because particulate matter, humic (organic) materials from land, and marine algae all absorb blue light. The H 2 0 absorbs red, so green is left for you to see.

57.  The angle of the sun’s rays and the state of the sea surface determine how much light is reflected and how much is absorbed. –When the sun is overhead only 2% is reflected. –When the sun is at the horizon 99% is reflected.

58.  Sea state, i.e. waves, increase absorption when the sun is low in the sky and decrease absorption when the sun is high in the sky.  Sun High / Rough Seas = _____ ______ __________

59. This is important at high latitudes where the sun is always low in the sky but sea conditions are frequently very rough. Sun Low / Rough Seas = _____ ______ _______

60. Refraction of Light in sea water  Light is refracted (bent) in sea water. –This makes objects appear larger. –This makes the sun always appear higher in the sky than it really is, i.e. when you are underwater it is always later than you think.

62. Pressure  All organisms on earth on under one atmosphere of pressure 14.7 pounds per square inch  For every 10 meters (33ft) you add another Atmosphere of pressure (see chart p.49)  Gases are under the same pressure

63.  Density is mass per unit volume  Density increases with decreasing temp and with increasing salinity  Density gradients lead to vertical stratification and thermohaline circulation Density

64. Thermocline and Halocline Thermocline – The layer of water where there is a big change in _________ Halocline- The layer where there is a big change in_________ Surface layer – Saltier and warmer why? Sun hits the surface warms the water and water evaporates leaving more salt

65. Pycnocline Pycnocline – The layer of water where there is the greatest change in _______ _________