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What goes down must come back up: Effects of 2010-11 La Niña on global sea level

Date:
November 19, 2012
Source:
NASA's Jet Propulsion Laboratory
Summary:
In 2010-11, global sea level fell nearly a quarter inch. But, when it comes to long-term sea level, what comes down must eventually come back up.
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A new NASA study finds that global sea level, which dipped sharply in 2010-11 due to a strong La Niña event, has recovered and resumed its long-term upward climb.
Credit: NASA/JPL-Caltech/CNES

For most of the past two decades, the NASA and European Topex/Poseidon, Jason-1 and Jason-2 satellites have tracked the gradual rise of the world's ocean in response to global warming. In August 2011, scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of Colorado in Boulder reported that global sea level rise had hit a speed bump.

The researchers found that between early 2010 and summer 2011, global sea level fell sharply, by about a quarter of an inch, or half a centimeter. Using data from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (GRACE) spacecraft, they showed that the drop was caused by the very strong La Niña that began in late 2010. This periodic Pacific Ocean climate phenomenon changed rainfall patterns all over our planet, moving huge amounts of Earth's water from the ocean to the continents, primarily to Australia, northern South America and Southeast Asia.

Now, a new paper published recently in the journal Geophysical Research Letters documents the effects of the 2010-11 La Niña on global sea level and updates the measurements. The result: as predicted, by mid-2012, global mean sea level had not only recovered from the more than 0.2 inches (5 millimeters) it dropped in 2010-11, but had resumed its long-term mean annual rise of 0.13 inches (3.2 millimeters) per year. Results of the new study are presented graphically at: http://photojournal.jpl.nasa.gov/catalog/PIA16294 .

"The water the ocean 'lost' was compensated for rather quickly," said lead study author Carmen Boening of JPL. "The newest data clearly indicate that the drop in 2010-11 was only temporary."

JPL co-author Josh Willis added that, like clockwork, the long-term rise of the ocean marches on. "The dip in global sea levels, brought to us courtesy of a major La Niña event, was little more than a pothole in the long road toward a rising ocean and shrinking coastlines," he said.

"In 2011, we detected a lot of water that was temporarily stored over land, causing severe flooding in some regions," said JPL co-author Felix Landerer. "In 2012, we have seen much of this water find its way back into the ocean."

For more information on NASA's satellite altimetry missions, visit: http://sealevel.jpl.nasa.gov/ . For more on GRACE, visit: http://www.csr.utexas.edu/grace/ .


Story Source:

The above post is reprinted from materials provided by NASA's Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Carmen Boening, Josh K. Willis, Felix W. Landerer, R. Steven Nerem, John Fasullo. The 2011 La Niña: So strong, the oceans fell. Geophysical Research Letters, 2012; 39 (19) DOI: 10.1029/2012GL053055

Cite This Page:

NASA's Jet Propulsion Laboratory. "What goes down must come back up: Effects of 2010-11 La Niña on global sea level." ScienceDaily. ScienceDaily, 19 November 2012. <www.sciencedaily.com/releases/2012/11/121119172938.htm>.
NASA's Jet Propulsion Laboratory. (2012, November 19). What goes down must come back up: Effects of 2010-11 La Niña on global sea level. ScienceDaily. Retrieved August 29, 2015 from www.sciencedaily.com/releases/2012/11/121119172938.htm
NASA's Jet Propulsion Laboratory. "What goes down must come back up: Effects of 2010-11 La Niña on global sea level." ScienceDaily. www.sciencedaily.com/releases/2012/11/121119172938.htm (accessed August 29, 2015).

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