Ocean Physics Unit 5

& Ability to Transmit Light and Sound Ocean Physics Physical characteristics of the world ocean is determined by water’s properties of… Heat Capacity Density Salinity & Ability to Transmit Light and Sound

Thermostatic Properties Ocean has a thermal inertia: it resists change in temperature. The poles receive less solar energy because the sun’s angle is further away, as compared to the tropics. The equator receives about 400% more solar energy than the poles. Currents in the atmosphere and in the ocean move heat from the tropics to the poles. ex. Gulf Stream Ocean currents and weather are a result of unequal solar heating. Heat transported by water vapor in atmosphere is greater than heat transported by water. Weather accounts for 2/3 poleward heat Ocean currents account for 1/3 poleward heat.

Light in the Ocean Refraction - bending of light waves, magnifying objects Refractive index - The amount light is refracted from one medium to the next The refractive index of seawater increases with salinity

Light in the Ocean Light is electromagnetic radiation that can have many wavelengths, other than just the visible spectrum. Only green and blue wavelengths pass through water at any appreciable depths and quantities. The ocean is the color it is because those colors are not absorbed but reflected back to you. As you go deeper, colors are absorbed except for blue and green. At 33 ft down, red appears gray. Underwater pictures appear their true color because a light source is used. Water color can also be a result of sediment, organisms (or lack there of), pollution or chemistry of water.

Sound in the Ocean Sound can travel great distances and 4-5x faster in water Speed of sound is faster in high temperatures and pressure. Sound is fastest at the surface and very deep. Loud noises at deep depths (sound channel) can be heard for thousands of km. Sound bounces off the thermocline to produce an area of poor sound transmission known as the shadow zone (subs hide here)

Equipment Hydrometer ratio of the density of the liquid to the density of water Calorimeter measures heat capacity pH meter/probe Measures pH Osmometer measures osmotic pressure Nansen bottle salinity measured at different depths bottle is sent down upside down on a string, flipped open at a desired depth, and a sample of water is taken Salinometer electronic electricity conductor Refractometer measures salinity by the degree the light is bent