Plenty of interesting and useful information is available to you from satellites. Satellites orbit the Earth, carrying sensors or other instruments. Many of these instruments use radar, visible light, or other means to produce pictures of the Earth. Others like the Argos System can locate transmitters on the Earth's surface and report the location or relay information from the transmitters to ground receiving stations. We will use the Argos System to locate the transmitters on travelling albatrosses in the Hawaiian Islands. At the nesting colony we will attach the transmitters to albatrosses when they are at their nests. From that point on, the Argos satellites will look for the transmitters every time they pass over the northern Pacific. If they locate one of the transmitters, they relay the location to ground stations in either Alaska, Virginia, or France. Eventually all of the location data end up in France, where they are processed and then sent every morning at 1:00 AM Eastern USA time to us at Wake Forest University, and we send the daily data on to the students participating in The Albatross Project.
What do satellites look like? The Coastal Zone Color Scanner (CZCS) is one that took some of the pictures you can see below; click here to see what it looked like before launch into orbit around the Earth. The CZCS measured the concentration of chlorophyll, a molecule in plants. The data from the CZCS showed where on Earth chlorophyll is most common, and where chlorophyll is common, plants are common, and where plants are common, animals that eat plants might be common. We might be able to use data from the CZCS to understand why albatrosses make the travel decisions that they do, because albatrosses eat fish and squid that eat smaller prey that eat plankton that eat algae. In an indirect way the albatrosses depend on algae for food. We'll be looking to see whether the albatrosses go to areas with high concentrations of algae. The CZCS stopped working in 1986, and the SeaStar satellite has taken its place. Click here for background on SeaStar and how it will be used to measure chlorophyll in the ocean.
Satellites are terrific for studying the El Niño-Southern Oscillation climate pattern. During El Niños unusual weather hits many parts of the Earth. In the Pacific Ocean, trade winds normally blow along the Equator from east to west. As they blow, they push water at the surface to the west. This surface water is warm from exposure to the sun, so the winds pile up warm water in western part of Pacific.
During El Niños those winds fail, and warm water flows
back to the east. A warm water pool appears in the eastern Pacific, often around
Christmas, hence the term El Niño, Spanish for "the Christ child." The
sea level height is greater than normal in the eastern Pacific during El Niños because
all of that warm water flowed back east. The surface temperature of the ocean in the
eastern Pacific is higher than normal. We speak of the unusual sea level height and
sea surface temperature as "anomalies." A positive anomaly means that sea
level height or sea surface temperature is higher than normal.
You can locate a lot of information from satellites on the web by searching with terms like:
"remote sensing," "satellite image," "NASA," "NOAA," "GOES," and "AVHRR"
This page was last updated on May 23, 2000 08:15 AM