Like Politics, All Sea-Level Rise Is Local

Jul 7, 2019

Much of what we hear about rising sea levels consists of long-range projections hundreds of years in the future -- projections that mostly consider the impact of melting ice.

But this global perspective won't tell you what will happen at any particular location. And it turns out, all sea level rise is local.

“The sea level change that we feel here in Woods Hole is not necessarily going to reflect what's happening on the global average,” Woods Hole Oceanographic Institution scientist Chris Piecuch told Living Lab Radio.

As the ocean warms due to climate change, the formation and circulation of deep, dense waters won't happen as much, which is expected to cause currents like the Gulf Stream to slow down. It may already be happening.

In 2009, scientists detected a decline of about 30 percent in this circulation at the same time as sea levels across the New England coast rose up to six inches. These simultaneous events raised the question of whether or not this was a cause and effect relationship. It also encouraged scientists to consider other, more local factors that can affect sea levels.

“One thing that's really important to understanding sea level change on our coast here in New England is what the local weather is doing,” says Piecuch. “If you have changes in how the winds are blowing, [or] whether you have high or low atmospheric pressure in a given month or season or year. Those things are really, really important to driving sea level changes.”

Piecuch’s recent research looks back at the conditions of the 2009 correlation and notes large scale changes in weather systems and sea levels that affected not only the northeast coast of the US, but also Europe and other locations. Piecuch’s team created models of sea level behavior, and when they applied the same wind and pressure conditions that occurred in the winter of 2009, sea level rose. The sea level rise referred not to the patterns of ocean currents in the Atlantic, but the meteorological conditions of that particular winter.

By looking at the implications of local conditions on sea level rise, Piecuch hopes to create a comprehensive picture of all the processes that affect sea level in order to create sea level forecasts that can give us insight into what rise might occur in the near future.

“That really is one of the outstanding goals of the oceanography and the sea level community,” says Piecuch. “Having these predictions or these projections that are not only 50 or 100 years out, but next month, next year.”

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Living Lab Radio is produced by Elsa Partan. Heather Goldstone is executive producer.