Tall Oceans and Global Warming

June 17, 2008 4 mb MP3

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Narrator: This summer, while you're relaxing, soaking up the rays at the beach, watching the ocean waves lap on the shore, a new satellite will be hard at work in its orbit high above Earth. Its assignment: to measure how high the oceans are, and how much they're rising - a rise linked to climate change.

Willis: Measuring sea level rise is really one of the most important things we do in terms of measuring global warming. The oceans absorb 85 or more percent of the heat from global warming. So if you want to know where does the heat from global warming go, it goes in the oceans.


Narrator: I'm Jane Platt with JPL -- NASA's Jet Propulsion Laboratory in Pasadena, California. The new Earth-orbiting satellite is called the Ocean Surface Topography Mission/Jason 2. Jason 2 for short. Josh Willis of JPL is an oceanographer with Jason 2. Its altimeter instrument will measure the peaks and valleys of the ocean surface, and how sea levels change over time. In general, our oceans are getting taller.

Willis: Global warming is causing the oceans to rise at a rate of about 3 millimeters per year, and this is a direct result of increasing the temperature of the atmosphere. That causes glaciers and ice sheets to melt, raising the levels of the ocean. But also, the ocean itself absorbs heat. And when that happens, again the water expands, stands a little taller, and this causes sea level rise as well, so the altimeter on OSTM, or Jason 2, will see both of these effects at it circles the Earth.

Narrator: Jason 2 will map the sea surface highs and lows every 10 days, tracking changes and helping scientists keep tabs on climate, and even weather. For example.

Willis: High sea surface is often a mark of warmer water, and warmer waters are essentially the fuels for hurricanes and tropical storms. So if a hurricane is about to pass over a patch of high sea level, there's a good chance that it might speed up and become more powerful.

Narrator: Jason 2 is third in a series of ocean-watching satellites from NASA and the French Space Agency. Jason 2's new technologies will get a better view than ever before of the oceans right near the coasts. Important real estate, since half the world's population lives near a coastline.

Willis: So we care a lot about sea level near the coasts. It affects things like beach erosion and fisheries, and many other things.

Narrator: Various industries will use data gathered by Jason 2. For example, the oil industry wants to better track giant ocean eddies, which are like underwater storms in the Gulf of Mexico.

Willis: They have enormous currents associated with them, and if they run over your oil rig, then it can cause a lot of damage. So predicting where these things are going to go and keeping track of them is very important to the offshore oil industry.

Narrator: And the utility companies also have an eye on that ocean info.

Willis: Power plants that use sea water as part of their cooling processes care a lot about the temperature of the sea water. And these large-scale patterns really tell us about how the seawater temperature is going to evolve over the coming years and decades.


Narrator: Whether you live near an ocean - or thousands of miles away from one -Jason 2 studies of the seas on planet Earth will have some effect on your life. For more info on Jason 2 and sea level, check out . Or . Thanks for joining us for this podcast from NASA's Jet Propulsion Laboratory.