What Are Convection Currents?
What causes ocean currents? Ocean currents result from two processes - the action of wind on the surface of the water, and from variation in water temperature that causes movement- a process known as convection. Convection occurs because the oceanic waters heat up becoming less dense. Apr 23, †Ј Convection currents transfer heat from one place to another by mass motion of a fluid such as water, air or molten rock. The heat transfer function of convection currents drives the earthТs ocean currents, atmospheric weather and geology.
What is the difference between weather and climate? Weather is the air temperature, cloud cover, precipitation, wind, moisture content, and air pressure at any particular time in any particular place. Weather reflects the prevailing conditions of the air masses overlying the land and seas over the entire globe. Climate is the overall picture of weather during periods of seasons or years. Historical records including geological and recorded history show us how the climate of the Earth has changed throughout its history.
The sun causes convection within the atmosphere, which in turn affects weather and climate. Find resources here to help students use real-time data to learn about the relationship between the sun, weather, and climate. Find resources here to help you better understand how convection impacts weather and climate, including some hands-on activities, lesson plans, real-time data and images.
This convection produces winds and ocean currents. The greater the pressure differences between a low-pressure area and a high-pressure area, the stronger the winds. Links for Teachers Links for Students Air masses and accompanying fronts do not remain stationary for long. What is the pension for congress movements are never exactly the same and they do exhibit some patterns that help meteorologists and others predict the weather.
Moving fronts indicate a change in the weather. Resources in this section direct students to real-time radar and satellite images to learn about weather patterns. Links for Teachers Links for Students Climate is the weather in a location averaged over a long period of time.
An old saying goes, "climate is what you expect, weather is what you get. Sample of Student Work 1. Weather and Climate Basics.
Convection In the Atmosphere
What causes ocean currents? Ocean currents can be caused by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes or storms. Currents are cohesive streams of seawater that circulate through the ocean. Oct 25, †Ј Convection currents occurring in the ocean Ц The Oceanic currents are also the convection currents. These are caused due to the difference in the water density and the temperature occurring in different parts of the ocean. Convection also plays a role in the movement of deep ocean waters and contributes to oceanic currents. Inside Earth, the convection of mantle material is thought to cause the movement of the overriding crustal plates, resulting in events such as earthquakes and volcanic eruptions.
Convection currents are identified in Earth's mantle. Heated mantle material is shown rising from deep inside the mantle, while cooler mantle material sinks, creating a convection current. It is thought that this type of current is responsible for the movements of the plates of Earth's crust. In the ocean, warm water is normally found near the surface while the deeper water is usually cold.
Deep, cold-water currents play an important role in creating the ocean oasis of the film. Convection currents play a role in the circulation of fluids. Convection currents are the result of differential heating. Lighter less dense , warm material rises while heavier more dense cool material sinks.
It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.
In the atmosphere, as air warms it rises, allowing cooler air to flow in underneath. Along with the turning of the Earth, this movement of air creates winds. Winds, in turn, create surface waves on the ocean. Convection also plays a role in the movement of deep ocean waters and contributes to oceanic currents. Inside Earth, the convection of mantle material is thought to cause the movement of the overriding crustal plates, resulting in events such as earthquakes and volcanic eruptions.
Part A Density and Convection Per student or pair of students: three 8 oz. Part B Convection Current Class Demonstration Small aquarium, water immersion heater, blue ice cubes, red food color, medicine dropper, small paper cup, tape. Part A Density and Convection small groups Discuss or review the concept of density relative to temperature.
Fill each plastic cup with 6 ounces ml of water. Allow the water to stand about 5 minutes. Fill a small container with very cold water. Add a drop of blue food color. Fill another small container with hot water. Add a drop of red food color. Use a medicine dropper to release a drop of hot, red water at the bottom of one cup. Observe and record the results.
Repeat, releasing the water on the surface. Record the results. In the second cup, repeat the process using the cold, blue water. What can you determine about warm water? Cold water? Which is more dense? In the third cup, simultaneously release hot, red water on the bottom and cold, blue water at the surface. Poke a few small holes in the paper cup.
Put the blue ice cubes in the paper cup. Tape the cup to the side of the aquarium. Turn the heater on. Release a few drops of red color at the bottom of the aquarium near the heat. Observe by looking through the side of the aquarium. Which is heavier, cold or warm water? Record your observations. Local Connection Observe local wind patterns. Where is the air warm? Where is the air cold? Which direction does the wind usually blow? Do you live near the ocean or other large body of water?
If so, find out about local currents. Do you ever swim or wade in a stream or river? Is the water colder at the surface or near the bottom? Key Words convection current. Continue to Activity 5: Onshore and Offshore Winds. What causes fluids to circulate? In the Film. To observe convection as a result of differential heating.