Waters of the Ocean

Water It makes up 80% of a Marine Organism’s body. ex 98% of a jelly fish

Other properties of water Adhesive – ability to attract to objects Cohesive – ability to attract to other water molecules. Hydrogen bonding occurs between water molecules. When Hydrogen is attracted to highly electronegative atom. Electronegativity- ability of an atom to attract electrons towards itself.

Nature of Water All matter is made up of atoms. Matter-Anything that has mass and takes up space. Atoms – smallest unit of matter Elements – Substance composed of individual atoms of the same kind. 104 known elements Molecule is two or more atoms that are forced together. H 2 0 is made up of 2 H atoms and 1 O atom.

Hydrogen bonding between water molecules

Water is a Polar molecule Uneven distribution of charged due to electrons not shared equally. This causes a partial negative on the Oxygen. The electrons are pulled toward the Oxygen that creates this uneven distribution of charge. Creates an Universal solvent. “Like dissolves Like” Polar substances dissolve other polar substances

Water molecules

Physical States of Water Exist in three states liquid, solid and gaseous Triple Point of water- When conditions are right. Conditions meaning temperature, pressure and volume, water can exist in all three states at once.

Changes of State Requires energy. Temperature reflects the average speed of the molecules Melting- solid to liquid Energy required – Latent heat of melting. Molecules begin to vibrate and break bonds to move away as temperature increases. Energy is absorbed by the bonds not into the speed of the molecular motion.

As the atoms breaks free, molecules speed increases with temperature. Water has a High Heat Capacity- Specific heat. 1.0 g/degree C Latent heat of evaporation ( heat of Vaporization)

Heat of fusion – Liquid to a solid All Changes of state requires a steady temperature except the specific heat of a substance that is depend on a change in temperature.

Water as a Universal Solvent Dissolves Salts – Combinations of particles with opposite charges. Ions- Particles that have given electrons away ( +) or receive electrons (- ) Crystals break apart from the water molecule pulling on the ions. Then once the ion is off, other water molecules congregate around it and carry it into solution.

Sea Water Salts come from two main sources. Chemical weathering of Rocks From the earth interior through the hydrothermal vents. Six ions compose 98% of the solutes in sea water Na and Cl ions makeup 85% of the solids.

Salinity Total amounts of salt dissolved in sea water. It is expressed over 1000 g of seawater that has been evaporated If you have 35 g of salt left, then the salinity is 35 o/oo parts per Organisms are affected by the kind of ions not the amount in the water. DITTMAR – A scientist that tested salt water for the consistency of ions in the water. Found the the amount did not vary.

Salinity Changes in salinity is controlled by : Precipitation Evaporation Freezing - ice is pure water/salt separates from it. All processes occur at the surface.

Salinity continued. Average Salinity – 35 0/oo Open Ocean varies from 33 – 37 0/oo Red Sea 40 o/00. Due to being partially enclosed. Baltic Sea 7 0/oo. Due to river runoff.

Salinity- Temperature - Density Saltier the water, the denser. Density depends on temperature and salinity of water. Open Ocean temperature 28 F to 86 F Salt water freezes below 0 C. Temperature varies considerable in the ocean. It is measured with a reversible thermometer. The mercury column breaks when inverted at the temperature reading from the water column. A series of these thermometers are use to develop a ocean profile.

Dissolved gases Oxygen, Carbon Dioxide, Nitrogen Gas Exchange between ocean and atmosphere occurs through a variety of processes.

Transparency Sunlight needed for plants to produce oxygen. Depends on materials on the water. Ocean water is most transparent to blue light from the visible spectrum of white light. Consist of: R O Y G B I V

Pressure Land organisms are less than 1 atmosphere of pressure. Pressure increases with depth with every 10 m another atmosphere is added. Gases are compressed, Gas filled structures tend to collapse.

Ocean Circulation Surface Circulation - surface currents are driven by wind. Coriolis effect influences surface current and wind - Earth rotates and is round which causes anything moving to be not in a straight line. In the Northern Hemisphere we tend to deflect to the right. In the Southern Hemisphere we tend to deflect to the left.

Wind patterns

Wind patterns winds driven by heat energy of the sun. Sun is directly over the equator. This causes direct heating. Warm air rises. Cooler air is sucked in this area and this creates wind. Winds are bent due to Corioles Effect. Trade Winds - blow at 45° angles towards the equator. They are the steadiest winds on Earth/ Why? No land around.

Westerlies - middle latitudes - moves opposite of trade winds - variable. Polar Easterlies - high latitudes - most variable winds - these are the most variable. Variable winds move opposite of Trade Winds. Surface currents - all major surface current are driven by winds.. Winds push the upper layer of the surface layer and moves at 45˚ angle. 2nd layer moves slightly to the right and slower. Upper part of surface current is called the Ekman Layer and they tend to move at 90˚ from the wind direction. Layers of water move in different directions and rates called the Eckman Transport

Gyres - huge circular movements of currents that carries warm water in one direction - regulate climate.

Cold water is carried in another direction. Currents regulate the climate on the Earth. Carrying heat from the tropics to polar regions. Continental shelf - currents tend to shape the bottom, shape coastline and affects tides.

Stability and Overturn Ocean is layered or stratified Dense water is on the bottom to the least at the top. Surface water stay always on top of the column of water is stable Only the winds and waves mix the deep water with the surface. Greater the difference in density the more stable the water column.

Overturn Surface Water sinks displacing less dense water below Profile (temperature ) is straight down, Occurs in the temperate and Polar regions in the winter when the surface water cools. It bring oxygen rich surface water to the deep sea.

3 Layered ocean Processes Changing: Temperature Evaporating- cooling Solar heating Heat exchange with the atmosphere. Water masses finger printed by temperature and salinity. This aids in the following circulation

3 layered ocean continued 1. Surface Layer ft- 660 ft deep --Mixed by wind, waves and currents. Called the mix layer --- Thermo cline occurs with a sudden temperature changes due to surface heating.

Intermediate Layer 1500 m (5,000) deep Main Thermocline Zone of Transition between warm surface water and cold water below and rarely breaks down,

Deep Bottom Layers 1,500 m (5,000 feet) uniformly cold less than 4 C

Waves Wind causes waves/ Wind is caused by the uneven heating of the earth. Waves carry energy over the surface. Water molecules do not move – only circular. The faster, longer the wind blows. The longer the wave.

Period – time it take a wave to go by any given point Fetch- determines the size of wave span of open water over which the wind blows. Seas

Wave Diagram

Fetch determines the wave span over the open water that the wave travels

Waves approaching shore- waves reaching a shallow area, wave will touch bottom. Bottom forces water molecules to travel in an elongated ellipses.

Water molecules approaching shore.

Swells

Waves cont………. This tends to slow the wave down. The wave catches up and pile up. Creating a shorter wave length. Wave becomes steeper and falls over as surf. White water effect is the water mixing with oxygen.

Breaking Waves

Breaker waves

Tsunami Originated from a Japanese word meaning “Harbor wave”, also called a Tsunami wave train. ‘Also called tidal wave. They are a series of water waves caused by the displacement of a large volume of a body of water? It can occur in a lake besides in a ocean.

Tsunami Wave Train

Tsunami in Japan

Causes Earthquake Volcanic eruptions Underwater explosion Landslides Glacier calving and other mass movements

Oceanographer – seismic sea waves First recognized in 425 B.C. Japan has the largest history. Tsunami are difficult to detect over deep water as the Tsunami approaches shore, water becomes shallow.

Wave Shoaling compresses the wave. Velocity slows below 50 mph Wavelengths diminishes to 12 mph, amplitude grow. The wave does not break. It flows in, then out.

Wave Shoaling

Tides Rising and falling of water in rhythmic patterns. Dominant influence on the seashore. It is caused by the gravitational pull of the moon and sun and by the rotation of the earth around the sun. Moon and earth are held together by gravitational attraction

Spring Tides Occur throughout the year. Tidal range is large. Occurs when the sun and moon are in line with the earth

Neap Tides Tidal Range is small Sun and moon are at right angles. Occurs at the 1 st quarter and 3 rd quarter of the month.

Tides –Real World Semi diurnal tides- 2 high tides and 2 low tides a day. Where? East coast of N. America and most of Europe and all of Africa

Mix Diurnal Tides Successive high tides of different heights. Where? West Coast of N. America and Canada

Diurnal Tides One High tide and one low tide everyday. Where? Coast of Antarctic, part of the Gulf of Mexico, Caribbean and Pacific.

Where does diurnal tides occur?

What affect Tides? Tide tables predict the time of the tides. What is used to create Tide Tables: 1. Islands, continents, ridges, basins, canyons, reefs- all affect tides. 2. Variations of orbits of sun and moon. Relative to the equator 3. Weather

Tidal Range Difference in water level between successive high and low tides