Sea level link to global temperature discovered
1 Sep 2016 by Evoluted New Media
The sea level rise in the world’s largest ocean could be used to estimate future global surface temperatures, according to US geoscientists.
The sea level rise in the world’s largest ocean could be used to estimate future global surface temperatures, according to US geoscientists.
Researchers used sea levels measured in 2015 in the Pacific Ocean to estimate that, by the end of 2016, the world’s average surface temperature will increase up to 0.28°C more than in 2014. In 2015, the global surface temperature increased by 0.18°C.
Cheryl Peyser, first author from the University of Arizona, said: “Our prediction is looking on target so far. We're using the pattern of sea level changes in the Pacific to look at global surface temperatures — and this hasn't been done before."
Peyser and a team of researchers used measurements of sea level changes taken from satellites belonging to NASA, the European Space Agency, and other European and American organisations.
They discovered that when western Pacific sea levels rose more than usual, the increase in global temperatures slowed. When the increase in sea levels occurred in the eastern Pacific — but not in the western area of the ocean — heat stored was released, increasing global surface temperatures.
Previous studies had shown climate cycles such as the Pacific Decadal Oscillation and the El Niño/La Niña cycle affects how much the surface of the Pacific Ocean physical tilts from west to east. Peyser used computer models to show how the climate system would change in the absence of global warming. These models established a link between the amount of tilt and global surface temperatures.
Peyser said: “What I found was that during years when the tilt was steep in the western Pacific, global average temperature was cooler. And when the seesaw is tilted more toward the eastern Pacific, it's warmer. We could say that for a certain amount of change in the tilt, you could expect a certain change in the temperature.”
The scientists’ next step is to figure out the mechanisms that allow the Pacific to change the global surface temperature so quickly. Peyser said she is not currently aware of any published theories on this mechanism. The research was published in Geophysical Physical Letters.
