NASA Satellite To Measure Global Sea Level Rise
The oceans are rising globally. The average sea level is more than eight inches higher now than it was an eighteen eighty in the trend is accelerating. npr's rebecca hersher has the story about a new satellite. That could help. Scientists understand how climate change is changing our seas. Here's her story. If you live near the coast you've probably seen. Booties and other contraptions edge that measure. What's going on in the ocean including how high the water is but when it comes to understanding global climate change. There is no substitute for satellite data from space. You can see the whole thing. Josh willis is a scientist at nasa. He's leading the us team. That's launching a new satellite called sentinel six in collaboration with the european space agency. Sentinel six zip around the globe. Eight hundred miles up and look at the surface of all the oceans. It's really kind of an incredible feat of technology. We can actually measure the water level with an accuracy of about one inch from eight hundred miles up. Centeno six uses radar to make continuous measurements. A radar beam comes down out of the satellite it bounces off that surface and then it measures the signal coming back and by figuring how long it takes to go down and come back. You can tell how far away the water is. If you know how far away the water is you can figure out how high it is relative to the land sentinel. Six is the latest in a string of satellites that do this kind of measurement going back to the nineties but those missions were somewhat ad and scientists couldn't always be sure that there would be an exhibition mission when the current one ended. Which is a nightmare when you're trying to understand how the climate is changing overtime. Which is why they are really excited. This time the satellite will be up there for five years and then another identical satellite will launch to another five years so a decade of reliable data llewellyn thompson studies oceans at the university of washington. I use that data every day in my research thompson has been studying how. The oceans have been changing for decades. She says obviously sea level rise is tangibly important to people who live on the coasts but ocean changes affect everyone. What happens in the ocean doesn't stay there. For example currents and ocean temperatures affect weather in fish populations we can also use to sea level measurements. Understand how currents are changing how ocean story heat and hotter oceans can drive more powerful hurricanes and scientists use steel data from satellites to figure out exactly how hot the oceans are getting too because water gets bigger as it gets hotter so by knowing the sea level. We have an indication of how much the ocean has expanded. Because of warning josh willis of nasa says the sentinel six satellite is crucial because climate change is happening fast in the past scientists had to make do with less data about the oceans but now the earth rapidly warming climate scientists need as much information as possible about what's happening around the globe. Sea level is continuing to rise. And we can't stop measuring it. Every year every decade we're remaking the climate and raising sea levels higher and higher sentinel is scheduled to launch a november twenty first from california rebecca. Hersher npr news.