At first thought, studying the oceans from space seems to be a bizarre idea.Space observation helps oceanographers do research with manned and unmannedspace systems. The space systems can be satellites and/or space shuttles thatobserve various features of the ocean such as sea-surface winds, sea-surfacetemperatures, waves, ocean currents, frontal regions, and sea color.Technological advances have greatly improved the ability of oceanographers togather and use information that is received.
Oceanography as viewed from spacehas and will become more and more valuable as we begin to understand more of theworld’s oceans. Projects Space oceanography uses a number of different sciencesto research the oceans that include physics, geology, biology, chemistry, andengineering (Cracknell 13). This is evident in the projects that send satellitesinto space for observation of our oceans. In 1992, the Topex/Poseidon projectwas launched to observe the interaction between the ocean and the atmosphere (Cracknell17). The Topex/Poseidon mission is to gather information about sea level heightsand ocean currents (Cracknell 17). The Topex/Poseidon orbits above the earth at840 miles and has a 10-day repeating cycle in which it takes pictures of all ofthe earth (Cracknell 17). Information about the how the sea level changes cantell scientists that there are changes in ocean currents and in climate patterns(Cracknell 25).
This information is valuable to both oceanographers andmeteorologists because it gives information about the phenomena, El Nino. Figure1 is a picture of how the Topex/Poseidon works. Figure 1(NASA) The Topex/Poseidonreceives information as to what it is supposed to do from a beacon on earth. Thesatellite then gathers the information it is supposed to gather and then sendsit to the beacon on earth.
The beacon on earth processes this information sothat scientists can use it. As the Topex/Poseidon nears the end of observationnew developments are being made to continue with similar work. Jason 1 is anobservation satellite that will look at extending research about the interactionof oceans with the atmosphere, improving predictions about the climate, continueto monitor El Nino, and observe ocean eddies (Cracknell 26). These satellitesare leading the way to a better understanding of our oceans as well as weatheron planet earth. History Observations of oceanographic features with pictureswere first realized with the invention of the camera (Pinet 181). Soon after theinvention of the Camera, hot air balloons were used to take high altitudepictures of the land and sea, for mapping purposes (Pinet 181). In World War II,pilots took pictures of large areas of land that were used to develop strategiesin the war (Pinet 181).
At the beginning of the space age, just after World WarII, rockets (although never in orbit) used movie cameras to photograph thesurface (Pinet 182). The first manned shuttles took pictures of Earth andrealized there were many observations of the oceans to be made (Pinet 182). Soonremote sensing came into action as satellites were sent into orbit (Pinet 182).Process of Remote Sensing Remote Sensing involves two types of instruments,passive and active (Gautier 58). Passive instruments detect natural energy thatis reflected or emitted from the Sun (Gautier 59). Scientists use a variety ofpassive remote sensors such as a radiometer, imaging radiometer, andspectrometer.
A radiometer measures the intensity of electromagnetic radiationin a band of wavelengths in the spectrum (Gautier 59). The spectrum is a measureof the visible, infrared (heat), and microwaves emitted from the Earth (Gautier60). An imaging radiometer has the capability to scan an area and provide pixelsof an area giving more detailed images of the surface than a radiometer (Gautier60). A spectrometer detects, measures, and analyzes the wavelengths of thespectrum using prisms to separate the colors (Gautier 61).
Active instrumentsprovide electromagnetic radiation to observe an object (Gautier 69). Satellitesthat use active instruments send a pulse of energy towards the object beingobserved, then wait for the energy to be reflected (Gautier 69). This energy isthen picked up as weaker or stronger in areas, which can define what featuresthe satellite is looking at (Gautier 70). Some active instruments are radar,scatterometer, and lidar (Gautier 71). Radar uses radio or microwaves to emitelectromagnetic radiation upon an object and record the time between when theenergy leaves and comes back (Gautier71). A scatterometer uses microwaves thesame way as radar, but it can measure wind speed and direction (Gautier71).Lidar uses lasers to transmit a light source on the object being observed, theycan calculate a number of elements in the atmosphere (Gautier 71).
With all ofthis scientists are able to determine the heights of the oceans, able to predictweather patterns and the effects on the ocean. Future Unmanned space systems arethe most cost-effective way to observe the planet (Victorov 109). The human eyehowever, has the best ability to observe the earth in a visual perspective (Victorov110). Humans in space play a valuable role in the observation of oceans (Victorov111). In the future people will be permanently stationed in space stations toobserve and research the earth (Victorov 111). How the satellites workSatellites that observe the surface of the earth rotate at the same speed as theearth, this enables them to take pictures from pole to pole (Victorov 123).Figure 2 is a diagram of a Geostationary Operational Environmental Satellite(GOES).
Figure 2(NASA) A “GOES” satellite rotates above the earth at22,000 miles. The camera on the satellite sends photographs back to earththrough its antenna (Robinson 34). Solar panels use the sun to produce energy,and the solar sail and trim tab keep the satellite from spinning out of orbitwhen the solar wind hits the satellite (Robinson 34). Ocean color can indicate anumber of things to an oceanographer, such as amount of plankton, and amount ofvegetation (Gautier 117). The color of the ocean changes slightly, from a brightblue to a dark blue or black (Robinson 118).
These changes in color happen whenplankton float freely and concentrate in areas (Robinson 119). Theseconcentrations are called blooms and are shown off the coast of Angola in Figure3. Figure 3 The ocean color can also turn into a blue-green because of thepresence of large amounts of vegetation (Robinson 124). Together, these colorscan indicate to scientists the productivity of the oceans and potential forgreater amounts to wildlife (Robinson 125).
Figure 4 is a false color image thatshows the amount of plankton in the ocean. Figure 4 The microscopic plankton arethe basis of the marine food web, without plankton all marine life would suffer.Thus, the importance of the information from the false color images of planktonon the earth becomes more valuable. Conclusion Oceanography is a new sciencethat will unleash a lot of new information to us on how planet earth works.
Oceanography from space will be a tool for find out more about our oceans, butthere are limited things it can do. It is expected that few major developmentsin oceanography will occur with satellites. The development of satelliteoceanography will bring together ideas from all sciences to an overallunderstanding about oceans and earth as a whole.Science