Ocean movements

Stuff regarding, movements of ocean water and their factors.

1. MOVEMENTS OF OCEAN INTRODUCTION WAVES TIDES OCEAN CURRENTS IMPORTANCE OF MOVEMETS CONCLUSION

2. GROUP MEMBERS HASNAIN RAZA MADAN LAL PAWAN KUMAR RAJNAISH AASWANI MUKHTIYAR AHMED MUHAMMAD ALAM

3. INTRODUCTION You all know that the ocean water is never still. There are different types of movements of ocean water under the influence of different physical characteristics like temperature, salinity, density, etc. Movements of ocean water are also affected by external forces like the sun, moon and the winds.

4. TYPES OF OCEAN MOVEMENT The major movements of the ocean waters can be classified into three. They are: 1. Waves 2. Tides 3. Ocean Currents Waves and the ocean currents are horizontal movements of ocean waters while the tide is a kind of vertical movement of the ocean water.

5. WAVES Waves are nothing but the oscillatory movements that result in the rise and fall of water surface. Waves are a kind of horizontal movements of the ocean water. They are actually the energy, not the water as such, which moves across the ocean surface. This energy for the waves is provided by the wind. In a wave, the movement of each water particle is in a circular manner. The time it takes for two wave crests to pass a fixed point is called the wave period. A wave has two major parts: the raised part is called as the crest while the low-point is called as the trough.

6. Surface waves have a rolling pattern of particle motion.

7. A wave has two major parts: the raised part is called as the crest while the low-point is called as the trough. The measurement between crest and trough of a wave is known as Amplitude or Height of wave. The measurement between crest to crest of trough to trough of a wave is known as wavelength.

8. Tsunamis The term tsunami comes from the Japanese words meaning harbor (" tsu ") and wave (" nami "). Tsunamis are the most dramatic and destructive of waves. Underwater disturbances, such as volcanoes, earthquakes and landslides, are the cause of these monster waves.

9. TIDES Tide are the periodical rise and fall of the sea levels, once or twice a day, caused by the combined effects of the gravitational forces exerted by the sun, the moon and the rotation of the earth. They are a vertical movement of waters and are different from movements of ocean water caused by meteorological effects like the winds and atmospheric pressure changes. Note: The water movements which are caused by the meteorological effects like the said above are called as surges and they are not regular like tides. The moon’s gravitational pull to a great extent is the major cause of the occurrence of tides (the moon’s gravitational attraction is more effective on the earth than that of the sun). Sun’s gravitational pull and the centrifugal force due to the rotation of earth are the other forces which act along with the moon’s gravitational pull.

10. The highest tides in the world occur in the Bay of Fundi in Canada. When the tide is channeled between islands or into bays and estuaries, they are termed as Tidal Currents. The regular interval between two high or two low tides is 12 hours 25 minutes.

11. Density Currents Density Currents are a type of vertical current that carries water from the surface to deeper parts of the ocean. Density Currents are caused by changes in density rather than wind. Density currents circulate thermal energy, nutrients and gases.

12. Impacts of Weather and Climate Warm-water currents and cold-water currents affect weather and climate in different ways Regions near warm-water currents are often warmer and wetter than regions near cold-water currents

13. FLOW TIDE AND EBB TIDE A flow tide or a flood tide is a rising tide or incoming tide which results in a high tide. It is thus the time period between a low tide and a high tide (i.e., the rising time). Ebb Tide is the receding or outgoing tide. ( It is the period between high tide and low tide during which water flows away from the shore).

14. TYPES OF TIDES Spring Tides : When the sun, the moon, and the earth are in a straight line, the height of the tide will be higher than normal. These are called as a spring tides. They occur twice in a month. One on the full moon (Poornima) and the other on the new moon (Amavasya).

15. Neap Tides : Normally after seven days of a spring tide, the sun and the moon become at a right angle to each other with respect to the earth. Thus, the gravitational forces of the sun and the moon tend to counteract one another. The tides during this period will be lower than the normal which are called as the neap tides. They also occur twice in a month- during the first quarter moon and the last quarter moon.

16. EFFECTS OF TIDES Tides act as a link between the port and the open sea. on the river Thames and Kolkata port on river Hugli are located on the rivers away from the sea coast. The tidal current clear away the river sediments and slows down the growth of delta. It increases the depth of water which helps ships to move safely to the ports. It also acts as a source for producing electricity.

17. OCEAN CURRENTS A current is the mass movement or flow of ocean water. There are two types: Surface Currents and Deep Currents Currents flow in complex patterns affected by wind, the water's salinity and heat content, bottom topography, and the Earth's rotation. They are very important in determining the climates of the continents, especially those regions bordering on the ocean.

18. Surface Currents : Surface ocean currents are generally wind driven. These currents move clockwise in the region of northern hemisphere. These currents move anti-clockwise in the region of southern hemisphere. Warm surface currents invariably flow from the tropics to the higher latitudes at the poles. Cold surface currents come from polar and temperate latitudes, and they tend to flow towards the equator.

19. What Influences Surface Currents? Ocean currents are driven by two forces: The Sun (which causes wind) The rotation of the Earth. Although wind blowing across the surface of an ocean can produce currents, these currents don’t continue moving in the same direction as the wind. Earth’s rotation causes ocean currents to bend to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This force that does not allow currents to flow in a straight path is called the Coriolis effect.

20. The Importance of Surface Currents The main importance of surface currents is to distribute the heat from the equator and the coldness from the poles. This “even” distribution of the temperature in the oceans helps to balance the heat budget here and in the atmosphere. The currents also influence the climate of an area. Warm currents keep coastal cities warmer and cold currents keep coastal cities cooler!

21. Deep Currents Deep currents are found in the deep ocean where there are lots of density differences. The two factors that affect the density of ocean water are temperature and salinity. By decreasing the temperature and increasing the salinity, the density of ocean water increases.

22. What is El Nino? El Niño (Spanish name for the male child), initially referred to a weak, warm current appearing annually around Christmas time along the coast of Ecuador and Peru and lasting only a few weeks to a month or more. Every three to seven years, an El Niño event may last for many months, having significant economic and atmospheric consequences worldwide.

23. Impacts of Weather and Climate Warm-water currents and cold-water currents affect weather and climate in different ways Regions near warm-water currents are often warmer and wetter than regions near cold-water currents

24. Gyres Due to the forces of gravity, the Coriolis effect, and winds, water often moves in a circular pattern called a gyre. Continents deflect ocean currents to the north and south causing closed circular current systems 5 major gyres: North Pacific, North Atlantic, South Pacific, South Atlantic, Indian Ocean.

25. Summery of Ocean Currents Mass flows of water, or currents, are essential to understanding how heat energy moves between the Earth’s water bodies, landmasses, and atmosphere. The ocean covers 71 percent of the planet and holds 97 percent of its water, making the ocean a key factor in the storage and transfer of heat energy across the globe. The movement of this heat through local and global ocean currents affects the regulation of local weather conditions and temperature extremes, stabilization of global climate patterns, cycling of gases, and delivery of nutrients and larva to marine ecosystems.

26. CURRENTS OF THE ATLANTIC OCEAN

27. CURRENTS OF THE PACIFIC OCEAN

28. CURRENTS OF INDIAN OCEAN

29. Importance of Tides Tidal flows are of great importance in navigation. Tidal heights are very important, especially harbors near rivers and within estuaries having shallow ‘bars’ at the entrance, which prevent ships and boats from entering into the harbor. Fish may concentrate during ebb tides. Commercial fishermen follow the tides and learn to fish during levels of highest concentration to improve their economic investment and to make more efficient use of their time. Tides and tidal currents affect the weather by stirring the ocean waters. The tides and tidal currents mix arctic water that can’t absorb lots of sunlight with warmer topic water that does. The stirring produces more predictable and habitable climate conditions and balances temperatures on the planet. Tidal energy is non-polluting, reliable and predictable. Tidal barrages, undersea tidal turbines – like wind turbines but driven by the sea – and a variety of machines harnessing undersea currents are under operation world over. Unlike wind and waves, tidal currents are entirely predictable.

30. Importance of Ocean Waves Ocean waves are very important for weather forecasting and climate modelling as well as for coastal communities, shipping routes and offshore industry. Recent studies of coupling atmosphere-ocean-wave models have shown improvements in the simulation of North Atlantic sea surface temperatures in climate models. Ocean waves are thought to play a role in weather forecasting such as improving hurricane intensity forecasts by regulating surface friction. Adding an ocean wave component to the next generation' of climate and weather models will provide an opportunity to address long standing biases. Extreme ocean waves continue to be a threat for coastal communities and the offshore industry. How ocean waves will change in the future will be of great interest to decision makers for coastal communities, shipping routes and the offshore industry.

31. CONCLUSION Different climates produce water masses of different densities. Sea ice generation in the polar regions creates very dense water masses. The different densities of water have set up a global circulation pattern which is drawn as an imaginary conveyor belt, that redistributes large amounts of heat around the earth.

32. You all know that the ocean water is not still. There are different types of movements of ocean water under the influence of different physical characteristics like temperature, salinity, density, etc. Movement of ocean is also effected by external forces like Sun, Moon and the wind. Currents are the horizontal movement of the ocean water while tide is a kind of vertical movement of the ocean water.

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