Water and Seawater: Pycnocline, Thermocline, Desalination, & Light transmission

1. © 2011 Pearson Education, Inc. Temperature and Density Variation With Depth Pycnocline – abrupt change of density with depth Thermocline – abrupt change of temperature with depth

2. © 2011 Pearson Education, Inc. Layered Ocean Three distinct water masses based on density: Mixed surface layer – above thermocline Upper water – thermocline and pycnocline Deep water – below thermocline to ocean floor High latitude oceans – thermocline and pycnocline rarely develop Isothermal Isopycnal

3. © 2011 Pearson Education, Inc. Desalinization Removing salt from seawater Distillation Most common process Water boiled and condensed Solar distillation in arid climates Electrolysis Electrode-containing freshwater Membrane between fresh and salt water tanks

4. © 2011 Pearson Education, Inc. Desalinization Reverse osmosis Salt water forced through membrane into fresh water Freeze separation Water frozen and thawed multiple times

5. © 2011 Pearson Education, Inc. Light Transmission in Ocean Water Visible light of the electromagnetic spectrum Blue (short) wavelengths penetrate deepest Longer wavelengths (red, orange) absorbed first Not in notes: write out – Light transmission depends on: Dust and cloud cover. Angle of the sun above the horizon. The smoothness or roughness of the sea. The amount of suspended material in the water.

6. © 2011 Pearson Education, Inc. Transmission of Light in Seawater

7. © 2011 Pearson Education, Inc. Color in the Ocean Color of ocean ranges from deep blue to yellow-green Factors Turbidity from runoff Photosynthetic pigment ( chlorophyll ) Secchi Disk – measures water transparency