January 5, 2006

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Riding the wave of ocean studies and climate change the legacy of Topex/Poseidon, wrapping up an Earth-observing mission. I'm Jane Platt, and you're listening to a podcast from JPL--NASA's Jet Propulsion Laboratory in Pasadena, Calif.


There's an old saying: "Everybody talks about the weather, but nobody does anything about it." Over the past 13 years, the Topex/Poseidon mission has changed all that. From its vantage point 830 miles above Earth, the orbiting satellite has helped scientists figure out what's happening with the climate, and how it affects weather patterns around our world. The satellite kept tabs on the ever-changing height and heat content of the oceans changes that determine climate. Dr. Bill Patzert is an oceanographer at JPL.

PATZERT: "The great event that really put Topex/Poseidon in the public eye was the great El Nino of 1997, 1998, and these were profound shifts in the heat content in the ocean and of course in the global climate. There wasn't anybody on the planet that wasn't touched by this El Nino."

And Patzert points out that this past year, Mother Nature has reminded us again and again of her power and fury. PATZERT "The great December tsunami in the Indian ocean, the very busy hurricane season over the United States, and so now scientists articulate as well as the media articulates these great shifts and these great events in terms of our Topex/Poseidon images."

NATURAL SOUND: music, then male news reporter: "This is a special report," followed by another male news reporter: "These latest satellite photos from NASA."

Topex/Poseidon's colorful maps of the globe, showing the oceans as splotches of purple, green and yellow, made their way into network news...

NATURAL SOUND: female reporter: "El Nino's worst storms aren't expected here until January"

Of course, when Topex Poseidon, a joint US-French mission, launched from French Guyana in 1992, Patzert and his colleagues had no way of knowing what historic events the spacecraft would witness, but they had high hopes.

NATURAL SOUND: Launch countdown in French, followed by rocket sound

PATZERT: "The expectations for Topex/Poseidon were sky-high. This was going to be the first global expedition of all oceans, albeit from space. For the first time we were going to have day to day, week to week, month to month, year to year views of the ocean variability. This is the key to climate variability and eventually to climate prediction, and so we were definitely all stoked."

They originally planned for 3 years of observations. Those three years stretched into a very productive 13 years for the hardy satellite. Topex/Poseidon sailed around Earth 62,000 times, with its high-tech instruments trained on the churning seas below. The satellite mapped the heights of sea surfaces around the globe. Higher levels indicate the oceans are warmer. The instruments watched as the vast oceans stored heat and moved it around the globe.

PATZERT: "Which is really the key to changes in climate. Which continents will be dry, which will be wet, some places will be warmer, some places will be cooler. So for the first time we were seeing a direct relationship between climate and weather and changes in the global ocean."

Topex/Poseidon Project Manager Mark Fujishin of JPL says the observations thrilled scientists, and had a huge impact on people everywhere.

FUJISHIN: "The science knowledge gained from Topex Poseidon affected millions, if not billions of people, and we were able to refine weather and ocean models and better understand those particular, particular events that are driven by the ocean."

Topex/Poseidon has witnessed dramatic changes over the past 13 years...Patzert and his colleagues are not sure yet what to make of the changes. Because the instruments measured sea surface height, Topex/Poseidon was also able to track the level of the oceans overall.

PATZERT: "Over the last 13 yrs, global sea level has risen almost an inch and a half. It doesn't seem like much, but over the past century, this is almost 10 inches of global sea level rise, and so it's really a preview of coming attractions for the planet. It's really the canary in the coal mine. The planet is warming and the sea level is rising."

Researchers are scouring the data and historical records to see whether these changes are part of an ongoing pattern, or really something new and dramatic.

NATURAL SOUND--RAIN: While scientists ponder climate change questions, everyday people soak in the drama of heavy rains and floods...events directly linked to the ocean patterns studied by Topex/Poseidon. Mark Fujishin.

FUJISHIN: "People are always more aware of things when it affects them in their own backyard, and because of the string of storms and hurricanes that have plagued the United States over the past year, people are much more aware of the tools that weather and climate folks use to detect short and long term weather patterns. And so this allows us of course to understand these phenomena greater, better, and make better predictions."

In addition to its normal ocean studies, there was a surprise observation in 2004 for Topex/Poseidon and its sibling, Jason, another US-French earth-observing mission. They caught the Asian tsunami building in the ocean right after the Sumatra earthquake. The team got the data back from the spacecraft after disaster had struck. Unfortunately, it was too late to help with that tragedy, but the day might be of use in future planning.

FUJISHIN: "Topex/Poseidon and Jason were the first on-orbit satellites to observe a tsunami in the open ocean. In other words, of course, we observe tsunamis as they hit land, but we were fortunate to be over that particular region of the Earth at the time. And the data received from the observation of this event will help scientists who study and track these types of events and even possibly help us in the prediction of the when and where of the next one."

Topex/Poseidon's long-lived adventure officially ended in December 2005, after the satellite's pointing instruments finally stopped functioning. The venerable craft will remain in orbit, but can no longer send back data. Carrying on where Topex/Poseidon left off, the mission's recent flying partner launched in December 2001.

PATZERT: "A smaller, less expensive clone named Jason, again a US-french joint mission was launched and they've been flying together now for almost 3 years which has provided an entirely new insight. Topex paved the way, Jason will continue to carry the banner, and as we look into the new century and the new millennium, we hope to have a continuous series of these altimetric satellites monitoring not only the oceans but providing the tools for climate forecasting."

Along with the next generation of satellites, there's a next generation of eager weather-watchers.

PATZERT: "I get emails from kids all the time from everywhere from middle school through high school, and even younger, asking about our images and climate change. And really that is the objective here, because the young people are really our future."

Patzert describes his years with the Topex/Poseidon team as the best experience of his life.

PATZERT: "Like all these great missions, we think of them as inanimate satellites, spacecraft, nuts and bolts, but it's really people. It's the men and the women, the scientists and the engineers that develop these great missions and 24 hrs a day, 7 days a week, 365 days a year operate the spacecraft with loving care here at JPL."

Mark Fujishin says with Topex/Poseidon, everyone came away a winner.

FUJISHIN: "The folks who fund NASA and its missions, specifically the taxpayers, really got their money's worth. They really got what they wanted to get out of this mission and much, much more."

The huge bank of data from Topex/Poseidon, coupled with new information from Jason, is routinely used by science and industry for a whole array of activities, including climate forecasting, ocean research, ship routing, offshore industries, fisheries management and marine mammals research.


More information on Topex/Poseidon, Jason and the Ocean Surface Topography Mission, with a planned launch in 2008, is online at http://sealevel.jpl.nasa.gov/ .
More NASA Podcasts are at www.nasa.gov/podcast.cfm . Thank you for joining us for this podcast from NASA’s Jet Propulsion Laboratory.