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Grade levels: K-4, 5-8, 9-12
Themes: 21st century technology, ocean circulation, water cycle
Flat Tool: http://ourocean.jpl.nasa.gov/AQUARIUS/chp2.jsp
GoogleEarth Interface Tool: http://aquarius.jpl.nasa.gov/AQUARIUS_DEV/chp2.jsp

Create global maps of mean conditions for any month at designated depths (down to 1500m) using the pull-down menus. Monthly time-series graphs of salinity, temperature, or density can be plotted by selecting up to six locations (by clicking on the map or typing latitude/latitude information into the fields below). These time-series graphs can also represent up to six different depths. Plotted data will also be shown in a table that is easily downloaded (e.g., into Excel). Sources include interpolated atlas data or actual measurements from the database.

Focus Questions | Flat Tool Tutorial

Grade level: 9-12
Theme: ocean circulation
Video: elnino-320.flv

Water vapor is a small but significant constituent of the atmosphere, warming the planet due to the greenhouse effect and condensing to form clouds which both warm and cool the Earth in different circumstances. A key feature of global atmospheric water vapor convection is the Intertropical Convergence Zone, the low pressure region within five degrees of the equator where the trade winds converge and solar heating of the atmosphere forces water-laden air to rise in altitude, form clouds, and then precipitate as rain in the afternoon.

	Legend for the water vapor animation, showing separate colorbars for total precipitable water and precipitation.

This visualization shows the global water vapor distribution in gray and white and the global precipitation in yellow every hour from December 20, 1997 to January 14, 1998. The afternoon thunderstorms in the tropics are seen as a flashing yellow region that moves from east to west, following the sun. This is an El Niño period, when the water to the west of South America is warmer than normal, allowing the atmosphere there to heat up and hold more water. This region feeds a high band of water vapor reaching to the southeastern United States and causes increased humidity and rainfall in that region.

These data are from the Goddard Earth Modeling System, a coupled land-ocean-atmosphere model which uses earth and satellite-based observations to simulate the Earth's physical system during events such as El Niño. (source)

Compare this video with Components of the Water Cycle: Flow of Atmospheric Water Vapor.

Grade levels: 5-8, 9-12
Themes: climate, ocean circulation
Activity: http://www.tos.org/hands-on/teaching_phys_concepts.pdf

Activity 4.3: Convection (p. 36-37). A good grasp of the underlying principles of thermal physics is essential for understanding how the ocean functions and how it impacts climate. Thermal physics is one of the science subjects that students are familiar with and experience on a daily basis, but intertwined with the experiential knowledge they bring to class comes a mixed bag of misconceptions that must be identified and addressed. Example misconceptions include an inability to differentiate between heat and temperature, the notion that transfer of heat will always result in a temperature rise, and a misunderstanding of the concept of latent heat.

The purpose of this activity is to review basic concepts of thermal physics and highlight applications to ocean processes by focusing on the concept of convection. Convection and advection are the major modes of heat transfer in the ocean and atmosphere. Convection occurs only in fluids and involves vertical motion of fluid, or flow, rather than interactions at the molecular level. It results from differences in densities - hence buoyancy - of fluids. Examples of convective processes include: currents in Earth's mantle, which drive the tectonic system and result from heating and cooling of magma; atmospheric circulation resulting from uneven solar heating (e.g., between the poles and the equator); the global ocean conveyor belt and formation of deep water masses, resulting from cooling of surface water at high latitudes; and vertical mixing in the ocean's upper layer due to variations in heating between day and night. Advection usually refers to horizontal transfer of heat with the flow of water (e.g., the Gulf Stream).

Read the following sections of Chapter 4 (Heat and Temperature) in preparation for this activity:

  •  Background (p. 32)
  •  Mechanisms of Heat Transfer (p. 33)

Flash Video | QuickTime Movie

Grade levels: 5-8, 9-12
Theme: ocean circulation
Video: density_effects.flv

I think most everybody can understand that if there is light fluid on top of heavy fluid then we have what's called a "stable system". Because things that are heavier are perfectly "happy" to be underneath something that's light. And what we say is that there is something that's less dense on top of something that's more dense.

But in the ocean it often happens that the reverse happens: so we might get something that's heavy, heavier (like) more dense waters on top of lighter water. And when that happens, we say that the ocean is unstable and we have "overturning". That means that the waters that are heavy come down to the bottom part of the ocean and those that are light need to go up. And that happens when waters are cooled and it also happens when the upper waters get saltier because of evaporation, etc.

So those density differences mean that the ocean is going to circulate: it's going to move. And those density differences can come about because of temperature changes or salinity changes.

Grade level: 5-8
Theme: ocean circulation
Activity: http://aquarius.nasa.gov/seawater_mix_sink.html

Big Idea

Key Concepts

Background
Density is weight divided by volume. The density of fresh water is 1 gram (mass) per cubic centimeter (volume). In other words, if you had a cube with the dimensions: 1cm x 1cm x 1cm; and filled it with pure water, that cube of water would weigh 1 gram. This density is expressed as 1 g/cm3. If you dissolve salt into the water, the salt will increase the fluid's mass, while its volume will remain the same. Thus, the liquid's density will increase. (more)

Grade levels: 5-8, 9-12
Theme: ocean circulation
Activity: http://www.tos.org/hands-on/teaching_phys_concepts.pdf

Activity 1.4: Effects of Temperature & Salinity on Density & Stratification (Steps 1- 4; p. 8). Stratification refers to the arrangement of water masses in layers according to their densities. Water density increases with depth, but not at a constant rate. In open ocean regions (with the exception of polar seas), the water column is generally characterized by three distinct layers: an upper mixed layer (a layer of warm, less-dense water with temperature constant as a function of depth), the thermocline (a region in which the temperature decreases and density increases rapidly with increasing depth), and a deep zone of dense, colder water in which density increases slowly with depth.

Stratification forms an effective barrier for the exchange of nutrients and dissolved gases between the top, illuminated surface layer where phytoplankton can thrive, and the deep, nutrientrich waters. Stratification therefore has important implications for biological and biogeochemical processes in the ocean. For example, periods of increased ocean stratification have been associated with decreases in surface phytoplankton biomass. In coastal waters, prolonged periods of stratification can lead to hypoxia (low oxygen), causing mortality of fish, crabs, and other marine organisms.

This activity compares salt and fresh water, demonstrating that fluids arrange into layers according to their densities. Students in grades 9-12 should read the Background section (p. 4-5) of Chapter 1 (Density) in preparation for this activity.

Flash Video | QuickTime Movie

Grade levels: 5-8, 9-12
Theme: ocean circulation
Activity: http://www.tos.org/hands-on/teaching_phys_concepts.pdf

Activity 1.4: Effects of Temperature & Salinity on Density & Stratification (Steps 5-7; p. 9). Stratification refers to the arrangement of water masses in layers according to their densities. Water density increases with depth, but not at a constant rate. In open ocean regions (with the exception of polar seas), the water column is generally characterized by three distinct layers: an upper mixed layer (a layer of warm, less-dense water with temperature constant as a function of depth), the thermocline (a region in which the temperature decreases and density increases rapidly with increasing depth), and a deep zone of dense, colder water in which density increases slowly with depth.

Stratification forms an effective barrier for the exchange of nutrients and dissolved gases between the top, illuminated surface layer where phytoplankton can thrive, and the deep, nutrientrich waters. Stratification therefore has important implications for biological and biogeochemical processes in the ocean. For example, periods of increased ocean stratification have been associated with decreases in surface phytoplankton biomass. In coastal waters, prolonged periods of stratification can lead to hypoxia (low oxygen), causing mortality of fish, crabs, and other marine organisms.

This activity compares warm and cold water, demonstrating that fluids arrange into layers according to their densities. Students in grades 9-12 should read the Background section (p. 4-5) of Chapter 1 (Density) in preparation for this activity.

Flash Video | QuickTime Movie

Grade level: 9-12
Theme: ocean circulation
Article: documents/21.1_yashayaev.pdf

The Labrador Sea is the coldest and freshest basin of the North Atlantic. Winter cooling in this sea produces Labrador Sea Water. This intermediate water plays an important role in the exchange of heat, freshwater, and other substances between the atmosphere and the abyssal ocean, affecting the water masses, circulation, and, ultimately, climate of the subpolar North Atlantic basins.

The subpolar gyre of the North Atlantic has exhibited large changes in temperature, salinity, and volume over the past six decades, largely in response to changing winter conditions over the Labrador Sea. The signature of these changes can be seen in the lower limb of the Meridional Overturning Circulation down into the North Atlantic tropics.

Read and discuss the Abstract and Introduction (p. 30-32).

Grade level: 5-8
Theme: ocean circulation
Video: salinity_importance.flv

The salt in the ocean affects its density, just like the temperature affects its density. And the density, meaning the amount of mass per volume, is going to then impact how the ocean circulates, it's going to impact where the water goes as it circulates throughout the globe.

Grade level: 9-12
Themes: climate, ocean circulation, water cycle
Video: melting_ice_03.flv

Two thirds of the fresh water on Earth is frozen in the world's ice fields. If that ice melts, seas will rise. If all of that ice were to melt, sea level would rise worldwide by 70 meters. No one expects all of that ice to melt anytime soon, but even the meter of sea level rise that many scientists predict for the next century could have dramatic consequences.

Lora Koenig: "Even though the polar regions seem very far from a lot of people's day to day life, they are very important. Because they are regions that cool our earth. And as they change, they're going to cause larger changes throughout the rest of the globe." (source)

Grade level: 9-12
Themes: climate, ocean circulation, water cycle
Video: melting_ice_02.flv

It's important to understand how the world's ice sheets form, how they change over time, and how fast they are moving into the sea. That's where researchers like NASA's Lora Koenig come in. She recently spent three months in Greenland studying the composition of those ice sheets. All ice sheets and glaciers start as snowfall. Those tiny flakes get compressed by the weight of more snow above, and eventually become dense masses of ice.

Lora Koenig: "What we're seeing right now on the ice sheets and glaciers is that they are shrinking in size. And as glaciers on land are shrinking overall, that contributes a little bit to sea level rise. And we are worried that as we see warming over the ice sheets, and increased melting over the ice sheets, that they are going to start contributing much more to sea level rise." (source)

Grade level: 9-12
Themes: climate, ocean circulation, water cycle
Video: melting_ice_04.flv

Josh Willis: "A lot of people live in coastal areas. Coastal places that have beaches. As sea level rises, then beaches begin to erode and we begin to lose wetlands. A lot of different ecologically-sensitive regions lie along the coastline, and as sea level rises, these get flooded (and) the ecosystems, of course, change. And so all of this can have big consequences for people and especially people who live near the coast."

Josh Willis: "As the great ice sheets in Antarctica and Greenland begin to melt and break up due to global warming, we really might experience very rapid sea level rise; three or four times as fast as the rate that we see today. So predicting this rate out into the future is very tricky because we really don't know when the ice sheets might break up and how fast they will when they do. So predicting future sea level rise is one of the great scientific problems of the future." (source)

Grade level: 9-12
Themes: climate, ocean circulation, water cycle
Video: melting_ice_01.flv

The ice is melting. The seas are rising. Little by little, in most parts of the world, the ocean is overtaking the land. Most of us don't think much about sea level rise, but it's one of the biggest signs that humans are affecting the Earth's climate. And it's something worth watching. So the big question is, are we facing a doom and gloom scenario?

Josh Willis: "I prefer not to think about climate change and global warming in terms of doom and gloom scenarios, so much as a change in our planet. Our planet's definitely changing, and we're definitely causing it. So we're going to have learn to deal with some of these changes. But in addition, we're going to have to learn how to make a slightly smaller footprint on our planet."

Josh Willis: "Sea level is rising effectively because of global warming. As the planet heats up, two things happen to the ocean. One is that the temperature of the water increases. And as that happens, the water actually expands and takes up more room. The other thing that happens is that ice that was on land in the form of glaciers and ice sheets begins to melt and as that runs off into the ocean, it increases the water in the ocean, and it actually raises sea level as well. (source)

Grade level: 9-12
Theme: ocean circulation
Tool: http://mynasadata.larc.nasa.gov/preview_lesson.php?&passid=68

While we inhabit land on the Earth we sometimes forget that we live on a planet where 70 percent of the Earth is covered with water. The variation in the properties of the land versus the water contributes to our global circulation patterns. Sometimes these global circulation patterns are disrupted and we observe the effects of these disruptions in events such as El Niño and La Niña.

It is believed that El Niños occur every two to eight years, and are sometimes stronger, sometimes weaker. This often happens when the southeast trade winds weaken or even reverse. As a result, large masses of water from the western Pacific Ocean migrate to the east to the coast of South America. This change in ocean circulation not only impacts the weather and climate in South America, but also affects locations all around the globe.

These effects can last for about a year, when the opposite conditions occur as the trade winds strengthen again, and the waters off the coast of South America are colder than normal from active upwelling occurring along the coast. This phase of the global circulation disruption is called La Niña.

We have been fortunate over the last 30 years to have satellite and buoy data to warn us if the El Niño phase is upon us. By measuring sea surface heights with satellites like TOPEX Poseidon, sea surface temperature with satellites like AVHRR, and wind vectors from buoys and satellites, we can monitor the Pacific Ocean for changes that may signal the onset of El Niño or La Niña. The sensitive altimeter on the TOPEX Poseidon satellite can measure small changes that create hills and valleys on the sea surface which is mostly caused by thermal expansion (steric effect), and the warming of the ocean during an El Niño event can be sensed by the altimeter.

This lesson explores El Niño by looking at sea surface temperature, sea surface height, and wind vectors in order to seek out any correlations there may be among these three variables. It employs group work where different teams work together to analyze a single variable, and then get together in different groups to compare all three variables. The lesson will guide students through data representing the strong El Niño from 1997 to 1998. By doing this, students will model the methods of researchers who bring their expertise to study integrated science questions. Depending on the classroom dynamics, available technology, and available time, this lesson may be modified.

Grade levels: 5-8, 9-12
Themes: climate, ocean circulation
Tool: http://oceanmotion.org/html/resources/oscar.htm

This data visualizer gives access to the following global ocean surface current behaviors between 1992 and 2008: current speed, current direction, current convergence, and current vorticity as well as the anomaly values for each.

Grade level: 9-12
Theme: ocean circulation
Article: http://www.nasa.gov/centers/goddard/news/topstory/2003/0114salt.html

NASA-sponsored scientists have discovered that by knowing the salt content of the ocean's surface, they may be able to improve the ability to predict El Niño events. Scientists, studying the western Pacific Ocean, find regional changes in the saltiness of surface ocean water correspond to changes in upper ocean heat content in the months preceding an El Niño event. Knowing the distribution of surface salinity may help predict these events.

This study, conducted for NASA by University of Maryland researchers Joaquim Ballabrera, Tony Busalacchi, and Ragu Murtugudde, is one of the first to look at ocean salinity in El Niño, Southern Oscillation (ENSO) predictions and their relationship to tropical sea surface temperatures, sea level, winds, and fresh water from rain.

Grade levels: 5-8, 9-12
Themes: climate, ocean circulation, water cycle
Video: salt_of_earth_03.flv

The oceans are vast, covering 70 percent of our planet, and so it is no surprise that we still know only a little about this system, and how it will respond to change, and furthermore, create change.

Jeff Halverson: "Climate change on earth is complicated by the fact that the ocean moves much more slowly than the atmosphere. So you have warming in the atmosphere, warming in the ocean, but they're occurring at different speeds. So they're out of sync, and that makes predicting what's going to happen in the next hundred or two years very, very difficult."

Susan Lozier: "Now what we might expect happens, in a very simplistic sense, is that as the ocean warms, there's going to be more evaporation. And that more evaporation would would mean that oceans become saltier. But really it's not just that simple because there's also evaporation, precipitation, and the ice as well, and that's all wrapped up in the study of the hydrologic cycle." (source)

Grade levels: 5-8, 9-12
Themes: climate, ocean circulation, water cycle
Video: salt_of_earth_02.flv

Susan Lozier: "And the atmosphere and the ocean, both being fluids of the earth, really work together. We consider them sort of equal partners in the redistribution of this heat on the planet. So when those warm waters are returning, as they're moving up to the higher and higher latitudes then, they're releasing that heat to the atmosphere. Then the winds blow over the ocean, they pick up that heat and those winds over the Atlantic Ocean are moving from the North American continent to the European continent."

Jeff Halverson: "It takes perhaps a thousand years for the water to cycle through the deep ocean. So we say the oceans have a memory. They're like a tape recorder. Things that happen now will still be manifest hundreds of years in the future as that cold water moves through this giant circulation."

Susan Lozier: "So if there's any change to that overturning circulation, that means that Northern Europe and the British Isles would be robbed of that heat due to those waters that are returning to the high latitudes." (source)

Grade levels: 5-8, 9-12
Themes: ocean circulation, water cycle
Video: salt_of_earth_01.flv

Susan Lozier: "And it seems a little odd in a way because salt is really a molecule in the ocean water, but collectively, that salinity plays a role in the ocean circulation."

It's these differences in salinity that play a role in the processes that affect weather, climate, sea life, and the whole ocean system itself. And not all oceans have the same salinity. In fact, the North Atlantic Ocean tends to be the saltiest, much more than the Pacific.

Susan Lozier: "The salt in the ocean affects its density, just like the temperature affects its density, and the density, meaning the amount mass per volume, is going to then impact where the water goes as it circulates throughout the globe."

Jeff Halverson: "Differences in temperature and salt content of the water cause some areas of water to sink and some areas of water to rise. And so we tend to see the sinking water at the poles, the water rising back up at the equator, and if you connect the two together, what you have is an overturning that is deep in the ocean. It's like a big conveyor belt that operates in the ocean."

This overturning moves warm water from the tropics toward the poles, and cold water from the poles toward the tropics. In this way the overturning regulates earth's climate. (source)

Grade levels: 5-8, 9-12
Themes: ocean circulation, water cycle
Video: density_reverse_direction.flv

The average density of sea surface water can be calculated from the average sea surface temperature and salinity using the state equation for seawater. This animation shows the long term average sea surface density, with light blue regions having the least density and dark blue regions having the greatest density. The sea surface density variations are actually very small, less than 3 percent overall, but the variation is very important.

There are three stable, dense regions in the ocean's surface, one in the sea around Iceland, Greenland, and Scandinavia and the other two near or under major Antarctic ice shelves. In these regions, the surface water becomes dense enough to sink and join the deep ocean currents. In fact, this sinking is thought to drive these deep currents as part of a system called the Thermohaline Circulation. This circulation has a strong effect on the Earth's climate, influencing the Gulf Stream, El Niño events, and both past and future climate shifts. (source)

Grade level: 9-12
Theme: ocean circulation
Video: sss_reverse_direction.flv

The heat of the sun forces evaporation at the ocean's surface, which puts water vapor into the atmosphere but leaves minerals and salts behind, keeping the ocean salty. The salinity of the ocean also varies from place to place, because evaporation varies based on the sea surface temperature and wind, rivers and rain storms inject fresh water into the ocean, and melting or freezing sea ice affects the salinity of polar waters.

This animation shows the long term average sea surface salinity, where white regions have the highest salinity and dark regions the lowest. Notice the higher salinity in the Atlantic, due partly to salty water coming from the Mediterranean, and the lower salinity at the mouths of major rivers. (source)

Grade level: 5-8
Theme: ocean circulation
Video: sst_reverse_direction.flv

The oceans of the world are heated at the surface by the sun, and this heating is uneven for many reasons. The Earth's axial rotation, revolution about the sun, and tilt all play a role, as do the wind-driven ocean surface currents.

This animation shows the long-term average sea surface temperature, with red and yellow depicting warmer waters and blue depicting colder waters. The most obvious feature of this temperature map is the variation of the temperature by latitude, from the warm region along the equator to the cold regions near the poles. Another visible feature is the cooler regions just off the western coasts of North America, South America, and Africa. On these coasts, winds blow from land to ocean and push the warm water away from the coast, allowing cooler water to rise up from deeper in the ocean. (source)

Grade levels: 5-8, 9-12
Themes: 21st century technology, climate, ocean circulation, water cycle
Flat Tool: http://ourocean.jpl.nasa.gov/AQUARIUS/chp1.jsp
GoogleEarth Interface Tool: http://aquarius.jpl.nasa.gov/AQUARIUS_DEV/chp1.jsp

Interactive maps of surface conditions can be clicked to create in-water profiles of salinity, temperature, or density. Sources include interpolated atlas data or actual measurements from the database.

Focus Questions | Flat Tool Tutorial

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: water_cycle_ipod_640x480.m4v.flv

This animation shows one molecule of water completing the hydrologic cycle. Heat from the sun causes the molecule to evaporate from the ocean's surface. Once it evaporates, it is transported high in the atmosphere and condenses to form clouds.

Clouds can move great distances and eventually the water molecule will fall as rain or snow. Ultimately, the water molecule arrives back where it started...at the ocean. (source)

Grade level: K-4
Theme: ocean circulation
Activity: http://aquarius.nasa.gov/water_cycle.html

Big Idea

Key Concepts

Background

Grade levels: 5-8, 9-12
Theme: ocean circulation
Video: thermohaline_conveyor_iPod.m4v.flv

Surface ocean currents are driven mostly by the wind. In certain areas near the polar oceans, the colder surface water also gets saltier due to evaporation or sea ice formation. In these regions, the surface water becomes dense enough to sink to the ocean depths. This pumping of surface water into the deep ocean forces the deep water to move horizontally until it can find an area on the world where it can rise back to the surface and close the current loop. This usually occurs in the equatorial ocean, mostly in the Pacific and Indian Oceans. This very large, slow current is called the thermohaline circulation because it is caused by temperature and salinity ("haline") variations.

This animation shows one of the major regions where this pumping occurs: the North Atlantic Ocean around Greenland, Iceland, and the North Sea. The surface ocean current brings new water to this region from the South Atlantic via the Gulf Stream and the water returns to the South Atlantic via the North Atlantic Deep Water current. The continual influx of warm water into the North Atlantic polar ocean keeps the regions around Iceland and southern Greenland mostly free of sea ice year round. The animation also shows another feature of the global ocean circulation: the Antarctic Circumpolar Current. The region around latitude 60 degrees south is the the only part of the Earth where the ocean can flow all the way around the world with no land in the way. As a result, both the surface and deep waters flow from west to east around Antarctica. This circumpolar motion links the world's oceans and allows the deep water circulation from the Atlantic to rise in the Indian and Pacific Oceans and the surface circulation to close with the northward flow in the Atlantic. (source)

Grade levels: 5-8, 9-12
Theme: ocean circulation
Video: thermohaline_rev.flv

The oceans are mostly composed of warm salty water near the surface over cold, less salty water in the ocean depths. These two regions don't mix except in certain special areas. The ocean currents, the movement of the ocean in the surface layer, are driven primarily by the wind. In certain areas near the polar oceans, the colder surface water also gets saltier due to evaporation or sea ice formation. In these regions, the surface water becomes dense enough to sink to the ocean depths. This pumping of surface water into the deep ocean forces the deep water to move horizontally until it can find an area on the world where it can rise back to the surface and close the current loop. This usually occurs in the equatorial ocean, mostly in the Pacific and Indian Oceans. This very large, slow current is called the thermohaline circulation because it is caused by temperature and salinity (haline) variations. This animation shows one of the major regions where this pumping occurs, the North Atlantic Ocean around Greenland, Iceland, and the North Sea. The surface ocean current brings new water to this region from the South Atlantic via the Gulf Stream and the water returns to the South Atlantic via the North Atlantic Deep Water current. The continual influx of warm water into the North Atlantic polar ocean keeps the regions around Iceland and southern Greenland generally free of sea ice year round.

The animation also shows another feature of the global ocean circulation: the Antarctic Circumpolar Current. The region around latitude 60 south is the only part of the Earth where the ocean can flow all the way around the world with no obstruction by land. As a result, both the surface and deep waters flow from west to east around Antarctica. This circumpolar motion links the world's oceans and allows the deep water circulation from the Atlantic to rise in the Indian and Pacific Oceans, thereby closing the surface circulation with the northward flow in the Atlantic.

The color on the world's ocean's at the beginning of this animation represents surface water density, with dark regions being most dense and light regions being least dense (see the animation Sea Surface Temperature, Salinity and Density). The depths of the oceans are highly exaggerated (100x in oceans, 20x on land) to better illustrate the differences between the surface flows and deep water flows. The actual flows in this model are based on current theories of the thermohaline circulation rather than actual data. The thermohaline circulation is a very slow moving current that can be difficult to distinguish from general ocean circulation. Therefore, it is difficult to measure or simulate.

This version of the visualization combines the Earth look of the original thermohaline visualization with the new thermohaline flow field generated for the Science on a Sphere production, "Loop". (source)

Grade level: 9-12
Theme: ocean circulation
Activity: documents/vtop_oc_variations_el_nino.pdf

An El Niño is thought to be triggered when steady westward blowing trade winds weaken and even reverse direction in the western Pacific Ocean, near New Guinea and Australia. This change in the winds allows the large mass of warm water that is normally located in the western Pacific to move eastward along the equator until it reaches the coast of South America. This displaced pool of unusually warm water affects evaporation and where rain clouds form, altering the typical atmospheric jet stream patterns around the world. Scientists are studying information from satellites and in-water buoys to better understand the causes and effects of an El Niño.

In this activity, students will analyze satellite images of sea surface temperature, sea surface topography, and wind data from an El Niño period and compare and contrast these data with non-El Niño conditions.

Grade levels: K-4, 9-12
Themes: ocean circulation, water cycle
Video: water_everywhere_02.flv

Paula Bontempi: "The water evaporates and goes into the atmosphere, and then it doesn't necessarily just turn around and fall as rain or snow."

Condensation is the process by which water vapor molecules cool, stick together, and become liquid again in cloud formation. This often happens high in the atmosphere where the temperature is much lower than it is near the surface.

Paula Bontempi: "What happens in the atmosphere is, just like we have currents in the ocean, we have winds in the atmosphere that actually, to some extent, drive what goes on in the ocean currents. Materials in the atmosphere can travel a great distance, sometimes a quarter of a way around the world, just until they get to the point where they actually turn into rain or snow and thereby fall back to the ocean or fall back to the land. This is called precipitation. If the water molecule falls on the land as snow, it may be stored for a very long period of time in a polar ice sheet or mountain glacier, depending on climate conditions."

Matt Rodell: "When rain falls or the snow melts, typically the next place it goes, it infiltrates the soil. So soil is not solid. It's not like a rock, there are pore spaces that can be filled with water and typically there is a certain amount of water in the soil at all times. If soil was completely dry, plants wouldn't be able to grow." (source)

Grade levels: K-4, 9-12
Themes: ocean circulation, water cycle
Video: WC_precipitation_IPOD.m4v.flv

This animation displays the intensity of precipitation as it flows around the globe, showing heavy precipitation in orange/yellow and light precipitation in purple. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle.

This animation was created using data from the GEOS-5 atmospheric model on the cubed-sphere, run at 14-km global resolution for 30-days. Variables animated here include evaporation, water vapor and precipitation. This animation is time synchronous throughout the animation to allow cross fades during compositing. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: water_everywhere_01.flv

Water is all around us, and its importance to nearly every process on earth cannot be underestimated. It is the only compound that can be found naturally as a liquid, gas, and solid. The process by which water moves around the Earth, from the ocean to the atmosphere to the land, and back to the ocean, is called the water cycle. Water regulates climate, storing heat during the day and releasing it at night, and carries heat from the tropics to the poles, by sea and by air.

Let's follow a single molecule of water, beginning in the ocean, through the paths it might take before eventually winding up right where it started - back in the big blue sea. The fuel for this journey will be provided by our planet's prime energy source: the sun. During the day, the sun heats up the air and ocean surface, causing water molecules to evaporate. Evaporation occurs when a liquid molecule of water escapes into the air as a gas.

This scientific visualization shows how water evaporation, indicated in turquoise, is driven by the energy of the sun. Notice how the rate of evaporation pulses over land: it speeds up during the day and almost disappears at night. Over the ocean, evaporation appears to remain constant, both day and night. Water in the air in gas form is known as water vapor. The molecule is now fresh water, having left the ocean salt and other particles behind. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: Evap_and_clock_IPOD.m4v.flv

This animation of evaporation shows how heating from the sun causes increased evaporation over land during the day. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle.

This animation was created using data from the GEOS-5 atmospheric model on the cubed-sphere, run at 14-km global resolution for 30-days. Variables animated here include evaporation, water vapor and precipitation. This animation is time synchronous throughout the animation to allow cross fades during compositing. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: WC_evaporation_IPOD.m4v.flv

This animation of evaporation shows how heating from the sun causes increased evaporation over land during the day. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle.

This animation was created using data from the GEOS-5 atmospheric model on the cubed-sphere, run at 14-km global resolution for 30-days. Variables animated here include evaporation, water vapor and precipitation. This animation is time synchronous throughout the animation to allow cross fades during compositing. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: WC_vapor_IPOD.m4v.flv

This animation portrays the flow of atmospheric water vapor around the world. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle.

This animation was created using data from the GEOS-5 atmospheric model on the cubed-sphere, run at 14-km global resolution for 30-days. Variables animated here include evaporation, water vapor and precipitation. This animation is time synchronous throughout the animation to allow cross fades during compositing. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: WC_SST_IPOD.m4v.flv

This animation of sea surface temperature shows the transport of heat along the ocean's surface. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle.

Data for this animation was derived from a model run of ECCO's Ocean General Circulation Model of heat along the ocean's surface. (source)

Grade levels: K-4, 5-8, 9-12
Themes: ocean circulation, water cycle
Video: WC_rivers_IPOD.m4v.flv

In this animation, pulsing of the global rivers highlights the flow of water from the continents back into the oceans. This video is a clip taken from Water, Water Everywhere which incorporates audio not included in this clip.

Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle. (source)