Ocean/Atmosphere/ Geosphere/Biosphere Atmospheric Circulation and Climate Coreolis Force Horizontal Ocean Circulation Vertical Ocean Circulation Circulation and Animals ENSO

Solar Energy Overall average Earth T: 15C Greenhouse gasses important to maintain Low light wavelengths (Visible light) to earth Earth re-radiates high wavelengths (heat; infrared)

Solar Energy Angle of incidence effects how much E to particular area (Ice ablation is also important in re-radiation) Solar radiation effects surface atmosphere circulation: atmosphere convection cells --> surface trade winds

Coriolis Force HypotheticalFrictional from Earth’s rotation N: clockwise (right) S: counterclockwise (left) Effects tradewinds, and ocean currents

Ocean Heat Budget Q = flux Basic equation: Q in - Q out = net accumulation If Q in > Q out, accumulation If Q in < Q out, loss If Q in = Q out, balance Ocean heat: (Q sun + Q circ ) - (Q rad + Q evap + Q cond ) = Ocean heat Q in Q out Q in Q out Currently: 53% evap, 41% radiation, 6% condensation Variable proportion of Q out per geographic region

Continent Effects Higher range of T changes over continents Water is better insulator: holds onto heat Winter, midcontinent: high P Summer, midcontient: low P --> alters ocean influences on climate Mountains disrupt atmospheric circulation patterns Tibetan Plateau uplift and monsoonal circulation Chain reaction: Ocean + solar radiation effects --> convection cells --> precipitation + continental effects --> runoff, sediment --> into ocean --> effects primary productivity

Horizontal Ocean Circulation Gyres Wind driven: friction Trade winds from atmospheric convection cells Lead to equatorial currents which leads to western boundary currents which leads to eastern boundary currents Equatorial + W boundary + E boundary = Subtropical Gyre Subpolar gyres also exist, smaller

Gulf Stream Western boundary current

Gyres

Horizontal Ocean Circulation Eckman Transport Wind driven: friction Assumes ideal water conditions Surface water: 3% wind velocity Bottom usually < 100m But…ideal conditions not real Other currents, wind variation, boundaries, water layers

Geostrophic Currents Differences in pressure: Pressure Gradient Force (PGF) Frictionless Water “piles up” in hill (max 1m; very low slope,100’s kms) Hi P uphill; water flows to lo P Coriolis force deflects flow When Coriolis = PGF --> Geostrophic Current Water circles “hill” Effects upwelling: ENSO events

Vertical Circulation: Upwelling Upwelling Common along continental margins Currents moved away from area --> upwelling Supports world’s fisheries San Diego -- LA coastline and sharks

Vertical Circulation: Upwelling

Vertical Circulation: Downwelling Wind pushes water onshore: water sinks, moves offshore

Cold Deep Currents Cold water sinks North Atlantic current, Antarctic Bottom Water hi O2, hi nutrients Balanced by upwelling

Vertical Circulation Thermohaline Circulation Density-driven Density is affected by temperature, salinity T effects > salinity effects Denser water sinks; less dense water rises  “Conveyer Belt”

“Conveyer Belt” Residence time at depth: ~300yrs using C14 on whole conveyer belt: estimated 1000yrs

Ocean circulation and Organisms Larval transport Adults: upwelling brings nutrients currents are predictable TransportFood timing of spawning After El Nino/La Nina Green and blue in ocean is high phytoplankton bloom (artificial color)

Zooplankton amounts Warmer colors = more zooplankton Blue hatch areas: sperm whale catches Gyres Conveyer Belt Upwelling

In upper Paleozoic times, supercontinent Pangaea: one large ocean: how would ocean currents, climate, effects on organisms be changed?