Ocean Chemistry – Chapter 6 Fe2+ Ca2+ NO3-

OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean

SeaSalt (Na+Cl-) Maio Island, Cape Verde, Africa -Nearly all minerals/ elements found in the Ocean. . ..

Foundations of Chemical Oceanography Joseph Gay-Lussay (1778-1850) Introduces the idea of the “WATER Column” Denotes depth-dependency of many ocean properties (esp. elements/minerals, e.g CaCO3 “calcite”) ALGAE Shells totally dissolve

“Liebig’s Law of Minimum” What does it state? Growth of plants controlled by a single element (required by plant) - but available at LOWEST rate of supply Challenge Question In this schematic which element would be rate limiting?

OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean

Recall - Periodic Table _Valence Electrons Outer valence electrons (= e-) participates in bonding of Elements 6 e- = (.) e.g. CO2 carbon dioxide .. .. O::C::O ‘‘ ‘’ Covalent bond Sharing e-  O=C=O CO2 4 e- = (.)

OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean

- - + - - - - + - - - + - - - + + + + + Water – It’s Unique Properties : O : H H - - + O- - - H+ - - + - - - + - - O- H+ H+ - + + Electro + part attract electro – part (Opposites attract) H+ + + + H2O molecules form Hydrogen bonds with other H2O molecules. . . (see above)  what makes water  b/c of +/- nature of H2O = great at DISSOLVING substances – aka UNIVERSAL SOLVENT (something that DISSOLVES)

Dissolving Power of H2O Water ~ universal (solvent) What trying to dissolve, aka = solute (e.g. salt) When too much of solute/solvent  precipitation (e.g. sugar crystals or salt) Compounds of Opposite charge molecules = “ionic compounds” – these dissolve best in H2O Anions (-) charge, e.g. Cl- Cations (+) charge, e.g. Na+

Salt, a solute, dissolves in water, a solvent Until a “saturation point” is reached Challenge Question? How can this be overcome? Increase temp. . . Solute dissolves

Airborne particles and the World’s Ocean Aeolian (air/wind) Input Red clay (to sediments) trace elements ~Iron (Fe2+) Rate limiting nutrient for plankton  algae bloom? With Iron comes increased Plankton blooms Plankton Blooms produce Dimethyl Sulfide (DMS)  Cloud condensation nuceli -Influences cloud formation MODIS satelite Fe2+ Fe2+ Fe2+ Fe2+ Dust from Africa . . . bloom bloom

OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean

Dissolved Elements of SeaWater The major constituents (elements of SeaWater)

Dissolved Elements in SeaWater The major constituents (elements of SeaWater) Know the big 5 (conservative ~ lots)

Oceanographers Use conductivity at diff. temps To determine salinity Throughout the oceans. . . Salinity affects density  Deep water - Ocean Circulation/Currents. . .Climate To be continued. .

Minor Constituents of Seawater Minor constituents (≤0.1 mMol/ kg, very dilute see Table 6.1) trace elements (Iron, Silica) (secondary metabolites – venoms, poisons) Marine Natural Products Cone Snail- Conus magnus Conotoxins (ziconotide- Prialt®) 1000Xs more potent then Morphine! morphine ziconotide

Biologically Important Nutrients: 2 classes: Macronutrients Nitrogen (N) Phosphorous (P) Potassium (K) micronutrients Iron (Fe) Silica (Si) Availability & Supply of nutrients Effect photosynth in world ocean More in Chap 13. . .

Dissolved Organic Matter (DOM) Dissolved Carbon “C” from bacteria decomposition Leaky marine organisms (incontinent) Terrestrial sources Important in Carbon Cycle Add to Oceans Color Can be seen by satellite Helps to track/model Carbon Cycle Chp.14 CO2 – climate change

Dissolved Gasses - Challenge Questions What are Zones of decreased and no dissolved Oxygen called? 1) Hypoxic Zone – decreased O2 levels 2) Anoxic Zone – no O2 !  Do gasses dissolve better with increased or decreased temperature? Decreased temperature Lots of nutrients (Missip river runoff) lead to Algae blooms - Zoo plankton - use up all O2 – ( Big fish suffocate)

Confirming your Knowledge What are the 5 major elemental constituents of SeaH2O? Cl, Na, S, Mg, Ca What are the Macro and micronutrients? N (nitrogen), P (phosphorous), K (potassium) (Macro) Fe, Si (micro)

OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean

Sources ( provide) & Sinks (remove) Minerals etc. The above determine concentration of elements in SeaWater CONTINENTAL Weathering: A Source Na from Continental Weathering Cl- from Vents? Volcanoes? (acid rain) not f/ river rocks (recycled as spray-Ocean Waves

Hydrothermal Vents: A Source & SINK Sources ( provide) & Sinks (remove) Minerals etc. Hydrothermal Vents: A Source & SINK +/- Minor source Consume other elements Lead, Sulfur, Copper, Iron, Cobalt, Ag Mostly gypsum & Zinc

Residence Times of Elements When sources/ sinks in balance – ocean is steady state At steady state – can define the amt. of time For total mass of an Element (e.g. Na) to be replaced aka Residence Time (how long it is in the ocean) Residence Time = mass of element present / rate of input or removal Na 1.472 x 1011 kg yr-1 tons/ year / 2 x108 tons/yr-1 Na/year = 70 million years!

Final Thoughts Turn in Long Lab Field Trip (HW-1) Please do HW-2 (due July 7th) Wed – Final Chemical Oceanography -CO2_The Oceans & Ocean Physics Fe2+ NO3- Ca2+

Fig. 6.16

Fig. 6.17

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Fig. 6.18

Fig. 6.19

Fig. 6.20

Fig. 6.21

Fig. 6.22

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PHOTOS

Opener

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Fig. 6.1

Figure 6a

Fig. 6.14

TABLES

Tab. 6.1

Tab. 6.2

Tab. 6.3