Ocean currents are formed due to differences in temperature, density, and planetary winds. Warm currents flow away from the equator while cold currents flow toward the equator. In 1992, a strange incident occurred where a ship lost a container of toys in the Pacific Ocean near Hawaii. These toys then traveled through the ocean currents, with some reaching Alaska after 10 months and others crossing into the Arctic Ocean by 2000. Ocean currents impact climate by keeping some coastal regions warmer in winter and influencing precipitation levels in other areas. They also concentrate nutrients and plankton which leads to large fishing grounds.
There are two types of currents in the ocean1) surface curre.docxssusera34210
There are two types of currents in the ocean:
1) surface currents move the water above the pycnocline
a) ≈ 10% of the ocean
b) horizontal motion
c) wind powered = solar powered
2) thermohaline = deep currents move the water below the pycnoline (zone of rapid change of water density)
a) ≈ 90% of the ocean
b) horizontal and vertical motion
c) density driven
density depends temperature and salinity
these are also solar powered
3) these two sets of current are interconnected
Chapter 7 – Ocean Circulation
Surface currents are moved by friction between the surface winds and the water surface = wind driven.
max speed is 3% of wind speed
Since winds are solar powered,
surface currents are solar powered.
The overall pattern of surface currents is controlled by the Coriolis effect, gravity, and the shape of the ocean basin.
Like Fig 7.7, p. 205
Ekman Transport – the net (or average) motion of wind driven water, is 90° to the direction of the wind. In a perfect world, this movement is:
90° to the right in the Northern Hemisphere,
90° to the left in the Southern Hemisphere, WHY?...........the Coriolis Effect
Fig. 9-, p. 236
In the northern hemisphere, the Westerlies tends to move water southeast, while the Trade winds move water northwest!
wind direction
wind-driven water movement (Ekman Transport)
The Westerlies (30° - 60°) and the Trade Winds (0° – 30°) are the strongest winds,* and are the
main winds causing ocean currents!
Largest change in temperature causes the strongest wind!
Remember, according to Ekman Transport, wind - driven water moves 90° to the wind direction.
In the northern hemisphere, the Westerlies tends to move water southeast, while the Trade winds move water northwest!
The movement of wind-driven water can be described with a vector = an arrow pointing in the direction of travel and scaled to the speed.
This vector can be broken up into a component moving toward the edge of the ocean and a component moving toward the center of the ocean.
wind direction water movement
vectors of water movement
The water moving east or west (toward the edge of the basin) bounces
off of the land.
In the northern hemisphere,
the water
current
turns right!
Current bounces off land
Current bounces off land
Subtropical Convergence = a short (≈ 6.5 feet tall) hill of water formed when part of the wind blow water moves to the center of the ocean basin.
Can water stand in a hill?
No!
Gravity works to move the water back downhill.
BUT the wind is still working to push water uphill again
So – The winds build the hill taller, and
The taller the hill the more gravity pulls the water back downhill
The hill continues to grow until wind driven Coriolis deflected motion in = gravity driven motion out.
Then – only the circular movement around the edge of the hill is left.
THIS IS THE SURFACE CURRENT!
Garrison, 2009, Essentials of Oceanography
Under the hill of wa ...
There are two types of currents in the ocean1) surface curre.docxssusera34210
There are two types of currents in the ocean:
1) surface currents move the water above the pycnocline
a) ≈ 10% of the ocean
b) horizontal motion
c) wind powered = solar powered
2) thermohaline = deep currents move the water below the pycnoline (zone of rapid change of water density)
a) ≈ 90% of the ocean
b) horizontal and vertical motion
c) density driven
density depends temperature and salinity
these are also solar powered
3) these two sets of current are interconnected
Chapter 7 – Ocean Circulation
Surface currents are moved by friction between the surface winds and the water surface = wind driven.
max speed is 3% of wind speed
Since winds are solar powered,
surface currents are solar powered.
The overall pattern of surface currents is controlled by the Coriolis effect, gravity, and the shape of the ocean basin.
Like Fig 7.7, p. 205
Ekman Transport – the net (or average) motion of wind driven water, is 90° to the direction of the wind. In a perfect world, this movement is:
90° to the right in the Northern Hemisphere,
90° to the left in the Southern Hemisphere, WHY?...........the Coriolis Effect
Fig. 9-, p. 236
In the northern hemisphere, the Westerlies tends to move water southeast, while the Trade winds move water northwest!
wind direction
wind-driven water movement (Ekman Transport)
The Westerlies (30° - 60°) and the Trade Winds (0° – 30°) are the strongest winds,* and are the
main winds causing ocean currents!
Largest change in temperature causes the strongest wind!
Remember, according to Ekman Transport, wind - driven water moves 90° to the wind direction.
In the northern hemisphere, the Westerlies tends to move water southeast, while the Trade winds move water northwest!
The movement of wind-driven water can be described with a vector = an arrow pointing in the direction of travel and scaled to the speed.
This vector can be broken up into a component moving toward the edge of the ocean and a component moving toward the center of the ocean.
wind direction water movement
vectors of water movement
The water moving east or west (toward the edge of the basin) bounces
off of the land.
In the northern hemisphere,
the water
current
turns right!
Current bounces off land
Current bounces off land
Subtropical Convergence = a short (≈ 6.5 feet tall) hill of water formed when part of the wind blow water moves to the center of the ocean basin.
Can water stand in a hill?
No!
Gravity works to move the water back downhill.
BUT the wind is still working to push water uphill again
So – The winds build the hill taller, and
The taller the hill the more gravity pulls the water back downhill
The hill continues to grow until wind driven Coriolis deflected motion in = gravity driven motion out.
Then – only the circular movement around the edge of the hill is left.
THIS IS THE SURFACE CURRENT!
Garrison, 2009, Essentials of Oceanography
Under the hill of wa ...
This is PPT of class -7 ,Geography, Chapter -5, Water
Reference book is NCERT, .
This is useful for teachers who teach in CBSE and Chhattisgarh board.
so download and use online and offline teaching.
Oceans are a vast body of salt water that covers almost three to fourths of the earth's surface.
Seas are smaller, found on the margins of the ocean and are partially enclosed by land.
Seawater:
High density, high heat capacity, colder, salty and slightly compressible (its volume decreases under pressure), thus its density increases with pressure.
Why is Ocean Circulation Important?
•Similar to winds in the atmosphere, they transfer significant amounts of heat from equatorial areas to the poles and thus play important roles in determining the climates of coastal regions.
•The ocean circulation pattern exchanges water of varying characteristics, such as temperature and salinity
•ocean currents and atmospheric circulation influence one another.
•in addition, they transport nutrients and organisms
Explore the dynamic world of ocean water and currents with this engaging PPT lesson by IAS Next. Dive deep into the intricate mechanisms governing ocean currents, their impact on climate, marine life, and more. Gain insights into the significance of understanding oceanic processes for various competitive exams, including IAS. This comprehensive presentation combines visuals and informative content to make learning about oceanography both educational and enjoyable.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
This is PPT of class -7 ,Geography, Chapter -5, Water
Reference book is NCERT, .
This is useful for teachers who teach in CBSE and Chhattisgarh board.
so download and use online and offline teaching.
Oceans are a vast body of salt water that covers almost three to fourths of the earth's surface.
Seas are smaller, found on the margins of the ocean and are partially enclosed by land.
Seawater:
High density, high heat capacity, colder, salty and slightly compressible (its volume decreases under pressure), thus its density increases with pressure.
Why is Ocean Circulation Important?
•Similar to winds in the atmosphere, they transfer significant amounts of heat from equatorial areas to the poles and thus play important roles in determining the climates of coastal regions.
•The ocean circulation pattern exchanges water of varying characteristics, such as temperature and salinity
•ocean currents and atmospheric circulation influence one another.
•in addition, they transport nutrients and organisms
Explore the dynamic world of ocean water and currents with this engaging PPT lesson by IAS Next. Dive deep into the intricate mechanisms governing ocean currents, their impact on climate, marine life, and more. Gain insights into the significance of understanding oceanic processes for various competitive exams, including IAS. This comprehensive presentation combines visuals and informative content to make learning about oceanography both educational and enjoyable.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2. Hello My name is Mohammed Zahid
Jameel Shaikh B-38 This is my
presentation On Oceanic currents
(lesson number.5)
This is what I have made
Introduction
3. Warm currents flow away from the
equator.
€
Cold currents flow toward the equator.
Ocean Currents
4. It will occur to you that as the temperature
of water increases, the plastic sequins move
from one place to another. As the temperature
rises, the density of water decreases and it
becomes lighter. And, therefore, the water
having lower temperature which is heavier
replaces the water with higher temperatures.
After sometime, the sequins start moving in a
circular motion. There is movement of these
sequins because of the flow of water.
Geographical Explanation
5. Strange Incident in Pacific occean in
1992
A very strange incident
occurred in the
Pacific Ocean in the year
1992. A cargo ship
sailed towards America
from Hong Kong.
While travelling through
the Pacific Ocean,
near the Hawaii Islands, a
container full of toys
fell into the ocean and
broke. Around 28000
6. Continue of 6th slide
the Arctic ocean by the year
2000. Some of them also
floated to Atlantic Ocean from
the
Arctic. Some of these reached the
eastern coast
of America in 2003 and some of
the toys had
even reached the European coast
by 2007.
7. Continue of 5th Slide
rubber toys started floating
on the ocean. This
incident occurred on 10th
January, 1992. Now
a strange thing happened.
After around 10
months, on 16th November,
1992, some of
these toys reached the
coast of Alaska. Some of
them crossed the Bering
Strait and moved upto
8. Continue of 7th slide
From the Hawaii Islands, some
toys took the
route to Australia! See figure 5.2
and 5.3
9. Explanation
The region from sea level to the depth of
500 m. is considered to be the surface water.
Sunlight can reach till this depth. The movements
in this layer occur mainly due to differences in
temperature and salinity. The planetary winds
give speed to the ocean currents.
10. Because of the rotation
of the earth, the ocean currents
move in
Rotation of the
Earth
11. Horizontal Surface Occean Current
Horizontal (Surface) Ocean Current :
The flow on the surface of the ocean moves
only 10% of the oceanic water. The surface
flow is considered up to 500 metres of depth.
The discharge of water in the oceans is
measured in Sverdrup unit. It is equivalent to 1
million cu.m./second discharge. The horizontal
flow of ocean water occurs as warm and cold
currents. These currents flow from the equator
to the poles and from the poles to the equator.
These currents are pushed to long distances by
the planetary winds. As a result, the ocean
waters flow from equator to both the poles and
vice versa.
12. There is similarity between the patterns
of the ocean currents of the Pacific and
Atlantic Ocean but the flow of the ocean
currents of the Indian Ocean are different.
The Indian Ocean is land-locked in the
north. The equator divides this ocean into
two parts- northern and southern. The
Monsoon winds influence this ocean
tremendously. These winds change their
direction according to the season. In the
northern part of the Indian Ocean, currents
flow in clockwise direction in summer while
in winter they flow in the opposite direction
due to reversal of Monsson Winds.
Fact of THE OCEAN CURRENTS OF THE
INDIAN OCEAN :
13. We have studied that ocean currents are
formed due to differences in temperature,
density and planetary winds. In addition, the
following reasons are also responsible for the
direction of flow of ocean currents and their velocity
clockwise direction in the Northern Hemisphere and in anti-clockwise direction
in the Southern Hemisphere.
Geographical Explanation
14. According to the
alignment of the coastline, the direction of the
ocean current changes. The velocity of the
ocean currents is around 2 to 10 km per hour.
The ocean currents are divided into two types-
cold currents and warm currents.
Continental Structure
15. Effects of Ocean Surface Currents on Human
life :
Ocean currents especially affect the
climate of the regions having proximity to the
sea. In cold regions where warm ocean currents
flow, climate becomes warmer. In some regions,
the amount of precipitation increases. For
example, the warm ocean currents flowing near
Western Europe, Southern Alaska, and
Japanese coast, reduce the intensity of the
winters there and make them warmer. As a
result, these ports do not freeze in winters.
Had ocean currents been absent, the ocean
water would have remained still. In such waters,
the biotic components would have been devoid
of food. Consequently, marine life and its
ecosystems would have been limited in its extent
In regions where cold and warm
currents meet, plankton, vegetation, algae, etc.
grow. This is food for the fish. Therefore, fish
come here in large numbers and breed……..
This
has, in turn, led to formation of large fishing
grounds. Grand Bank near the North American
coast in Atlantic Ocean and Dogger Bank near
the European coast are some of the examples.
With respect to the water transport too, the
ocean currents are very important. If the
transportation is done according to the flow of
ocean currents, the speed of the ships increase
and the fuel is saved too.
Near the coasts where cold currents flow,
the amount of precipitation is low. For example,
in Peru, Chile and the arid desert of South-West
Africa.
At places where the cold and the warm
currents meet, thick fog is formed. Such fogs
create problems for transportation. The warm
Gulf Stream and the cold Labrador currents
meet near the Newfoundland island. This leads
to dense fog. Because of the cold currents,
icebergs are carried away from the polar areas.
If such icebergs come along the marine routes,
they are hazardous to the ships.
17. Deep Occean currents
Water currents beyond the depth of
500
metres are known as deep
water/ocean currents.
These currents are formed due to the
differences
in temperature and density of the
water in
different parts of the ocean. This is
known as
thermohaline circulation. These
currents flow
till the sea-bed of the ocean. They
flow like
rivers continuously below the surface
of the
sea. See Figure 5.5.
18. Deep occean currents
The difference in temperatures of various
parts of the ocean is the major reason behind
the deep-sea currents. Warm water has lower
salinity and density. Such water comes to the
surface of the sea. Cold water with high
density
goes down. This movement causes the deep
sea
water currents. See figure 5.6. Generally, the
surface water near Greenland and Europe
moves to more depths. This water moves to
the
Antarctica at these depths. Later the water
moves to the surface. Thus, the redistribution
of the ocean water keeps occurring. This
redistribution takes around 500 years to
complete. This type of movement is also
known
as conveyor belt.
of this circulation, ocean water
moves from thesurface to the
bottom and from the bottom
tothe surface. Warm water is
transferred to thebottom from
the surface and the nutrient-
richcold water is circulated to the
surface.
19. Due to thermohaline circulation, movement of sea water occurs on a
large scale. Because of this circulation, ocean water moves from the
surface to the bottom and from the bottom to
the surface. Warm water is transferred to the
bottom from the surface and the nutrient-rich
cold water is circulated to the surface.
These circular pattern of themovements of the ocean currents, give
riseto certain peculiar features in the ocean.They are called gyres. The
Sargasso Sea inthe Atlantic Ocean is such an example. It ismarked by
the circular patterns of oceancurrents . It does not have land
boundariesand is only surrounded by ocean currents.It gets its name
from the Sargassumseaweed. The water is still here. This sea is1100
km wide and 3200km long.
Importance of deep occean currents