Background Image http://www.futura-sciences.com/img/willy.jpg Ocean Currents & Ocean Currents & Climate Climate •The ocean and its currents have a major influence on weather and climate on Earth. •In this unit we will see how interactions among the hydrosphere, lithosphere, atmosphere, and the ocean produce weather and climate changes. •On the following slides, the green sections are the most important. Underline words = vocabulary! Image
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Background Image Ocean Currents & Climate The ocean and its currents have a major influence on weather and.
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•The ocean and its currents have a major influence on weather and climate on Earth.•In this unit we will see how interactions among the hydrosphere, lithosphere, atmosphere, and the ocean produce weather and climate changes. •On the following slides, the green sections are the most important.Underline words = vocabulary!
• The major landmasses on Earth are connected by moving water called ocean currents.
• A current is a large mass of continuously moving ocean water.
• The largest currents that move across the ocean are called global ocean currents. These currents are like rivers that travel great distances.
• Ocean currents are affected by global temperature, freshwater glacial ice melt, and density differences due to salt concentrations and temperature differences.
• Throughout the history of Earth the climate has gone through periods of warmth and periods of extreme cold (often known as an Ice Age). This is a natural phenomenon.
• Some scientists claim that the warming trend is part of a natural cycle that will eventually reverse itself through CO2 uptake by photosynthetic marine and terrestrial plant life.
• Others claim that the warming of Earth’s atmosphere is a real problem that can be reduced by decreasing the use of fossil fuels and finding alternative energy sources.
source of all energy on Earth, gives off radiant energy and influences the climate that we experience.
• The amount of radiant (or solar) energy that reaches any part of the planet depends on the angle at which the rays of the sun strike the surface. (Angle of Isolation)
• The Earth’s curved surface and the tilt of its axis causes areas farthest away from the sun’s rays (the poles) to receive slanted rays with a smaller angle, and are therefore less intense.
• The gulf stream current flows from the southwestern Atlantic to the northeastern; it is the major factor in favorable (warm) weather on the eastern coast of the United States.
• Benjamin Franklin was the first to chart the temperature and speed of the gulf stream back in the 1700s.
• You can see that the gulf stream flows northeast up the coast of the United States. The satellite image shows it carries with it very warm water.
storm with a wind velocity exceeding 120 km per hour.
• Hurricanes form in warm tropical seas where there is hot, moist air. Such conditions contain the heat needed to fuel a hurricane.
• As hot, moist air rises, it cools in the upper atmosphere and condenses into ring shaped clouds. During condensation, a great deal of heat energy is released, which causes more hot air to rise even quicker. This whirlwind of rising air moves in a spiral direction around calm air knows as the “eye” of a hurricane.
• View the animation from NASA by clicking the graphic.
famine in Africa, floods in California, and other climate disturbances in recent years have all been caused by changes in the warm ocean currents around the globe.
• Oceanic warming is called El Nino.
• El Nino begins in the western Pacific Ocean.
• Warm currents are normally carried northwest due to trade winds.
• El Nino reverses the currents because of a decline in southeast trade winds and causes a change in the climate of South America (bringing floods and stormy weather).
La NinaLa Nina• Unusually cold currents causing cooler surface
temperatures is known as La Nina. • During La Nina years (when ocean currents are unusually
cool in the mid-Pacific) winters are cooler than normal in the northwest United states and warmer than normal in the southeast.
• The cycles for El Nino/La Nina often last 1 to 2 years and occur every 4 to 6 years. Click on the graphic to view an animation depicting the differences between El Nino and La Nina.
• Ocean currents on planet Earth drive the weather and stabilize the climate.
• Changing of ocean currents and related factors such as trade winds can have devastating effects (El Nino, La Nina, rising sea levels, etc).
• In order to understand the complex factors that create Earth’s climate you need to understanding the forces of density, salinity, and Earth’s temperature as they relate to ocean currents.
Journal: Future of Global WarmingUsing the political cartoon at the left, predict earth in the future and explain why the cartoonist chose to use the image to image a future earth after global warming. Is this a possible effect of an increase in global temperatures?