Introduction to Oceanography Introduction to Oceanography Lecture 14: Tides, Biological Productivity Memorial Day holiday Monday no lab meetings Go to any other lab section this week (and let the TA know!) Bay of Fundy -- low tide, Photo by Dylan Kereluk, . Creative Commons A 2.0 Generic, Mudskipper (Periophthalmus modestus) at low tide, photo by OpenCage, Wikimedia Commons, Creative http://commons.wikimedia.org/wiki/File:Bay_of_Fundy_-_Tide_Out.jpg Commons A S-A 2.5, http://commons.wikimedia.org/wiki/File:Periophthalmus_modestus.jpg Tides Earth-Moon-Sun System Planet-length waves Cyclic, repeating rise & fall of sea level • Earth-Sun Distance – Most regular phenomenon in the oceans 150,000,000 km Daily tidal variation has great effects on life in & around the ocean (Lab 8) • Earth-Moon Distance 385,000 km Caused by gravity and Much closer to Earth, but between Earth, Moon & much less massive Sun, their orbits around • Earth Obliquity = 23.5 each other, and the degrees Earth’s daily spin – Seasons Photos by Samuel Wantman, Creative Commons A S-A 3.0, http://en.wikipedia.org/ wiki/File:Bay_of_Fundy_Low_Tide.jpg and Figure by Homonculus 2/Geologician, Wikimedia Commons, http://en.wikipedia.org/wiki/ Creative Commons A 3.0, http://en.wikipedia.org/wiki/ File:Bay_of_Fundy_High_Tide.jpg File:Lunar_perturbation.jpg Tides are caused by the gravity of the Moon and Sun acting on Scaled image of Earth-Moon distance, Nickshanks, Wikimedia Commons, Creative Commons A 2.5 Earth and its ocean. Pluto-Charon mutual orbit, Zhatt, Wikimedia Commons, Public Domain, To Sun http:// en.wikipedia.org/ wiki/File:Orbit2.gif Not to scale! Newton’s cannon, Wikimedia Commons, Creative Commons A S-A 3.0, http://en.wikipedia.org/wiki/File:Newton_Cannon.svg • Basic Orbital Mechanics • Earth-Moon Distance Brews Ohare, Wikimedia, Public Domain, http://en.wikipedia.org/wiki/File:Earth- • Planetary objects stay in orbit due to balance of Gravity – 384,000 km Moon.PNG and Centrifugal forces (at their center of mass) • Revolution period of the Moon • Like a weight spun on the end of string – 27.3 Days • Rotation period of the Moon also 27.3 Days • Synchronous Rotation: We always see the same side of the Moon 1 Phases of the Moon Phases of the Moon • New Moon • Waxing Crescent • 1/2 Moon: First quarter 1st Qtr WAXING CRESCENT • Full Moon First • Etc. Quarter New – 7 days/quarter Full Full Moon Third Quarter WANING CRESCENT rd Tom Ruen, Wikimedia 3 Qtr Commons, Public Domain, http://en.wikipedia.org/wiki/ Figure from NASA Starchild, Public Domain), File:Moon_phase_calendar_ http://starchild.gsfc.nasa.gov/Images/StarChild/icons/ May2005.png moon_above.gif The Big Picture 3: Bulges The Moon and Sun both influence tides Figures from U. Tennessee, http://csep10.phys.utk.edu/astr161/lect/time/tides.html • Moon’s gravitational force acting on the Earth tugs out a tidal bulge towards moon • Centrifugal force pushes a bulge away from moon on the far side of the Earth – TIDES TRY TO TRACK THE MOON NOAA, Public Domain, http://oceanservice.noaa.gov/education/kits/tides/media/tide06a_450.gif The Sun’s gravity has a similar, Constructive interference: Sun and Moon tidal bulges oriented the but smaller effect (1/2 as strong). same way, resulting in strong tides – Spring Tide Destructive interference: Sun and Moon tidal bulges partially Andrew Buck, Wikimedia Commons, Creative Commons A S-A 3.0, http:// commons.wikimedia.org/wiki/File:Tidal_braking.svg cancel each other, resulting in weak tides – Neap Tide Effect of Sun & Moon Together Why is the moon’s effect on the tide • Spring Tides & Neap Tides greater than the sun’s? • Gravity balances Centrifugal at Earth’s center of mass • Elsewhere they don’t cancel – TIDE GENERATING FORCE: GMMoon Ftides ∝ 3 REarth− Moon • Tide generating force falls off faster with radius than gravity! Adapted from figure by Nicky McLean, Wikimedia Commons, Public Domain, http://en.wikipedia.org/wiki/ € File:Tide.Bridgeport.30d.png 2 Equilibrium Theory of the Tides Tides in narrow, tapering bays • In narrow bays attached to the ocean, tides can slosh straight in and out Sun is much more massive! • Large tides can occur when the tidal frequency matches natural 7 » Msun ~ 3x10 Mmoon (resonant) oscillations BUT Sun is much further away! of the bay » Rsun ~ 400 Rmoon GMs F R3 M R3 1 S ≈ SE = s mE = 3×107 × = 0.47 GM 3 3 FL m Mm RSE 400 R3 Image from NOAA Online mE School for Weather, Public Domain, http:// www.srh.noaa.gov/ jetstream/ocean/ Solar tide 1/2 as big as lunar tide fundy_max.htm € Bay of Fundy tides QUESTIONS? Mont Saint-Michel and Tombelaine (tidal islands), France, Uwe Küchler, Wikimedia Commons, CC A S-A 3.0, http://commons.wikimedia.org/wiki/File:Mont_st_michel_aerial.jpg Marine Life & Biological Productivity CLASSIFICATION SCHEMES FOR MARINE ORGANISMS 1. Taxonomy: Based on genealogical relationships between organisms (ie, felines) 2. Mode of Nutrition 3. Habitat 4. Mobility Estimated marine chlorophyll & terrestrial vegetation coverage map 1997-1998, SeaWiFS/NASA, Public Domain, http://en.wikipedia.org/wiki/File:Seawifs_global_biosphere.jpg 3 Genetic classification: Three Domains of Life Bacteria Cyanobacterial colonies, left: NASA, Public Domain, http://microbes.arc.nasa.gov/images/content/gallery/lightms/ 1. Bacteria: Simple single celled organisms, lack publication/lyngbya.jpg; right: Hamelin Pool -- Shark’s Bay, Australia, photo by Happy Little Nomad, Wikimedia commons, CC A S-A 2.0, http://en.wikipedia.org/wiki/File:Stromatolites_in_Shark_Bay.jpg nucleus (E. coli) 2. Archaea: Outwardly similar to Bacteria; many live in extreme environments (hot springs, nuclear reactors, saline lakes, etc.) 3. Eucarya: Have a membrane-enclosed nucleus and other organelles; include protists, animals, fungi, plants Whole genome tree of life, diagram by User_A1, based on Ciccarelli (2006) and Letunic (2007), Public Domain. http:// en.wikipedia.org/wiki/ File:CollapsedtreeLabels- simplified.svg Archaea Eukaryota Ostreococcus, a picoplankton (<1x10–6 m across!), Wenche Eikrem and Jahn Throndsen, University of Copepod, NOAA, Public OsloWikimedia Commons, CC A S-A Domain, http:// 2.5, http://en.wikipedia.org/wiki/ www.glerl.noaa.gov/pubs/ File:Ostreococcus_RCC143.jpg photogallery/Waterlife/ pages/0737.html Thermococcus Gammatolerans, an Archaebacterium, Halobacteria (actually Archaea) and Eukarya (Dunaliella Angels Tapias, Wikimedia Commons, Creative salina), San Francisco Bay CA, dro!d, Wikimedia Commons A 3.0 Unported, http:// Commons, Creative Commons A S-A 2.0 http:// commons.wikimedia.org/wiki/ commons.wikimedia.org/wiki/ File:Thermococcus_gammatolerans.jpg File:Salt_ponds_SF_Bay_%28dro!d%29.jpg Public Domain Questions? What does it eat? 1. Autotrophs: Make their own food; Cyanobacteria, NASA, Public are the base of the food chain Domain, http:// microbes.arc.nasa.gov/images/ content/gallery/lightms/ a. Autotrophs are Primary Producers publication/lyngbya.jpg b. Photosynthesizing plants, algae, some bacteria (store solar energy) c. Chemosynthetic bacteria Sargassum natans (eukarya), James St. John, Creative Commons Attribution 2.0 Generic, https:// commons.wikimedia.org/wiki/ Comb jelly(?) (Eukaryota), Nick Hobgood, Wikimedia Commons, Creative Commons A S-A 3.0, File:Sargassum_natans_(brown_algae)_(San_Salvador_Is http://commons.wikimedia.org/wiki/File:Combjelly.jpg land,_Bahamas)_1_(15867880028).jpg 4 What does it eat? Photosynthesis Living systems require chemical energy 1. Heterotrophs: cannot make their own food; must Chlorophyll: a green pigment that captures photons and transfers their energy to eat other organisms or their remains electrons, an through a series of steps creates carbohydrate molecules (chemical energy) and oxygen. a. Herbivores: eat plants Chlorophyll looks green because it absorbs red and blue light, and reflects green light b. Carnivores: eat animals Sargassum algae, NOAA, Public Domain, http://oceanexplorer.noaa.gov/ Adapted c. Omnivores: eat plants & explorations/02sab/logs/aug09/media/ from figure lines.html by Aushulz, animals Wikimedia Commons, Creative d. Bacteria: many decompose Commons A dead organic matter (E. coli) Barracuda are heterotrophs, NOAA, Public S-A 3.0, Domain, http://www.photolib.noaa.gov/htmls/ http:// reef2567.htm commons.wi kimedia.org/ wiki/ File:Chlorop hyll_ab_spe So are yeast, ctra2.PNG Masur, Wikimedia Commons, Creative Commons A S-A 2.5, http://en.wikipedia.org/wiki/ File:S_cerevisiae_under_DIC_microscopy.jpg Photosynthesis Reaction sunlight PRIMARY PRODUCTION 6CO + 6H O ——> C H O + 6O 2 2 6 12 6 2 • Amount of inorganic carbon (mainly Carbon CO2) “fixed” by autotrophic organisms + water (yields) Glucose + Oxygen into organic compounds dioxide (a sugar) – Based on reactions harnessing solar or chemical energy Typically, ~100 grams carbon/ year / meter2 is fixed to sugar in the open ocean Respiration • Respiration: opposite reaction of photosynthesis Questions • Dis-assembly of carbohydrate (food) molecules in the presence of oxygen to release chemical energy • The main byproducts of respiration are H2O and CO2. These are released to the environment • Both plants & animals use respiration • Some bacteria & archea also respire + ENERGY C6H12O6 + 6O2 ——> 6CO2 + 6H2O Glucose + Carbon (a sugar) Oxygen (yields) + water dioxide Sargassum, photo from South Atlantic Fishery Management Council, http://www.safmc.net/Portals/6/weedline%202.jpg 5 How can we measure productivity? How can we measure productivity? Color-imetry! (yes, it means what you think) -Timed weighing of autotrophs - Chorophyll enables
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