After Brief Decrease Last Year, Sea Levels Resume Their Steady Rise
It is no secret that for the last couple decades, as Earth's climate has been changing, sea levels have been steadily rising. But what is not so well known is that in 2011, sea levels throughout the world fell sharply. Of course, with a body of water as large as the world's oceans, a sharp fall only equates to one quarter of an inch (1 cm). It is nonetheless, a dramatic change in general trend which caught the eye of NASA and European researchers. Using advanced satellites, they were able to track average sea levels with precision accuracy. What they have found is that after this brief decrease in sea levels, the seas have been rising again and are now back on track with their trajectory of the last twenty years.
The lull occurred between early 2010 and summer 2011. Using the NASA/German Aerospace Center’s Gravity Recovery and Climate Experiment (GRACE) spacecraft, they found that the drop was due to a very strong La Nina that began in late 2010. This phenomenon which occurs in the Pacific climate changes rain patterns all across the planet, moving immense quantities of water from the oceans and depositing them on continents, particularly Australia, Southeast Asia, and northern South America.
According to a new study recently published, researchers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, CA found that by mid-2012, global mean sea level had recovered the quarter inch that it dropped in the previous year. Plus, it resumed its long-term annual rise of 0.13 inches (3.2 mm) per year.
"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."
Co-author Josh Willis added, "The dip in global sea levels, brought to us courtesy of a major La Nina event, was little more than a pothole in the long road toward a rising ocean and shrinking coastlines."
The severe flooding that occurred during the La Nina has managed to find its way back to the oceans, as the ever-constant hydrologic cycle on Earth continues to find its equilibrium.
Image credit: NASA/JPL-Caltech/CNES