Download Sea Surface Temperature

Sea Surface Data Help Sheet
There are many environmental factors to be considered when studying the sea surface.
As an ACES student, you have the opportunity to look at sea surface temperature,
weather, sea ice, sea height, currents, and wind. Each of these factors influences the
animal that you are studying. When you click on “sea surface” in the maps and data page
there is satellite data for each environmental factor. The data will help you explain your
observations about the animal’s movement.
Sea Surface Temperature
Sea Surface Temperature (SST) is a measure of the amount of heat stored in ocean water.
It is measured in degrees Celsius. The ocean covers 70% of the Earth’s surface and they
store and release heat into the atmosphere, helping to keep the climate within a
temperature range that is habitable. As you learned in “Lesson 6: The Sea Surface,” heat
is not evenly distributed throughout the ocean. Some areas of the ocean are warmer than
others. Most species prefer to live in a certain temperature range and will migrate to
areas where the temperature is optimal for their survival.
The following map shows the track of the Olive Ridley Turtle. What do you notice about
the SST in the areas where the turtles swim?
That’s right! These turtles all stay in areas where the water is about 28-30 degrees
Celsius. This species likes the warm waters of the Pacific Ocean and cannot tolerate
colder water. They like to feed on jellyfish which also prefer warm waters. This
example shows how SST is directly linked to the specific needs of a species.
SST is also linked to food supply. Cold water holds more oxygen than warm water.
Therefore, organisms that require a lot of oxygen, like fish, prefer cold water. Areas
where warm water and nutrients run off the land into the ocean are often locations where
phytoplankton blooms occur. These are good feeding grounds for many marine species.
Use the SST maps in addition to your own research to identify the needs of your animal
and try to explain or justify their migration pattern.
Weather
Weather conditions also influence the movement of marine animals, most specifically
those that fly. The Black-footed Albatross for example prefer to migrate farthest during
clear days, not during storms. The stormy conditions that result from low pressure
systems create conditions that most animals do not like to travel in – just like us!
However, marine birds will take advantage of moving masses of air to help power their
flight.
The map below shows weather data for Oski on September 24, 2008. The data shows
clouds moving from west to east in a line, or front. Oski may have taken advantage of
this front to fly about 350 kilometers in one day.
Weather data is collected from satellites that take pictures of the Earth. Clouds are shown
as white areas that reflect light from the satellite camera. The whiter the cloud, the
thicker it is. You can use weather data to figure out why your marine animal chose to
travel or to stay put on a certain day.
Sea Ice
Sea Ice Imagery can help you determine the location of ice relative to your animal. Some
animals rely on sea ice to meet their needs and their movement is closely linked to the
growth and retreat of sea ice. Other animals cannot tolerate sea ice and stay away from
it.
The behavior and movement of polar bears is directly linked to sea ice. Polar bears rely
on ice to hunt seals and build dens to care for their young. They are adapted to the
extreme cold and are accustomed to the building up and retreating of sea ice as seasons
change.
Sea ice data is given as a percentage. Each color on the color bar corresponds to an
amount of ocean area that is covered in ice, ranging from 1 – 100 percent. Remember that
ice floats on top of water, so the percentage describes how much of a certain part of an
ocean has ice covering it. Satellite images are broken up into squares, called pixels. A
pixel may be 1 kilometer by 1 kilometer, or bigger or smaller, depending on what
scientists are interested in observing.
Each image below shows sea ice cover in a pixel of ocean water. Notice how the sea ice
covers the ocean and how it appears on the satellite image.
Notice in the map below that Ajax migrated across the entire Arctic Ocean on sea ice.
Sea Height
The sea’s surface is not perfectly flat; it is lumpy. Sea height data is a measure of the
changes in ocean depth for a particular day. The scale has both positive and negative
values. Think of zero as the average sea height. Any negative number means the depth
is less than average and any positive number means that the depth is greater than average
on a particular day.
In warm water, the water molecules move fast and spread out from one another.
Therefore, the water’s surface gets a bit higher. On a sea height image, warm areas will
appear red, orange, and yellow.
Conversely, cooler water will have a slightly lower sea height because the molecules
move closer together. Cooler areas will appear blue and purple on sea height images.
Observe the map below for Southern Elephant Seals. The sea height data is for
September 23, 2008. A closer look at this map will show that all seals stayed in blue
areas on this date. Lower sea height often means cooler water than surrounding areas.
Recall that cooler water often means that there is upwelling and more food availability.
By interpreting the data in this way, you may be able to identify some of the specific
needs of your animal and explain why they move as you observe.
Currents
Moving rivers of water within the ocean, called currents, help to circulate warm and cold
water throughout the world’s oceans. Currents are measured in meters per second, which
calculates the distance (meters) divided by the time (seconds) that the water is moving.
The speed at which an ocean current is moving is indicated by the color on these images.
Faster colors are red and orange; slower ones are in the blue range. The arrows indicate
the direction of the current’s flow.
Currents not only affect how heat is distributed around the world, they also carry
nutrients and marine life. Some marine animals make use of currents for their migration.
Jamur, the Leatherback Sea Turtle enjoyed a ride in the Gulf Stream as he crossed the
Atlantic Ocean. Satellite data for currents can help explain why marine animals move
when and where they do.
Wind
Wind patterns are another environmental factor that influences the movement of marine
animals. Wind is also measured in meters per second, like currents. The color bar helps
show areas with strong winds, many meters per second, and areas with weak winds, few
meters per second.
The map shows wind data for November and the path that Sammie, a Greater Shearwater
used to travel south. Sammie migrated from the east coast of the United States to South
America. Use the color bar to identify the speed of the wind during the November dates.
You probably noticed that areas in yellow and orange have stronger, faster winds than
areas in beige and white. In November, Sammie was traveling against wind blowing 912 meters per second. Notice that when she reaches areas where the wind is not as
strong, she can travel farther distances in between data points.
Wind direction and speed can help explain why animals are able to travel certain
distances over time. Wind also influences the direction of currents in the ocean.
Additionally, wind and weather data together can give a good picture of the atmospheric
conditions that make it a good or bad travel day. Take a look at the wind data for your
marine animal.