To accommodate the trillions of calculations needed for such small-area resolution, they used the new high-performance computer cluster at WHOI called "Scylla."
"Global models predict significant temperature increases in the central tropical Pacific over the next few decades, but in truth conditions can be highly variable across and around a coral reef island," Cohen said.
"To predict what the coral reef will experience in global climate change, we have to use high-resolution models, not global models."
The model predicts that as air temperatures rise and equatorial trade winds weaken, the Pacific surface current will also weaken by 15 percent by the end of the century.
The then-weaker surface current will impose less friction and drag on the EUC, so this deeper current will strengthen by 14 percent.
"Our model suggests that the amount of upwelling will actually increase by about 50 percent around these islands and reduce the rate of warming waters around them by about 0.7 C (1.25 F) per century," Karnauskas said.
A handful of coral atolls on the equator, some as small as 4 square kilometers (1.54 square miles) in area, may not seem like much.
But Karnauskas' and Cohen's results say that waters on the western sides of the islands will warm more slowly than at islands 2 degrees, or 138 miles, north and south of the equator that are not in the path of the EUC.
That gives the Gilbert Islands a significant advantage over neighboring reef systems.
"While the mitigating effect of a strengthened Equatorial Undercurrent will not spare corals the perhaps-inevitable warming expected for this region, the warming rate will be slower around these equatorial islands," Karnauskas said.
"This may allow corals and their symbiotic algae a better chance to adapt and survive."
If the model holds true, even if neighboring reefs are hard-hit, equatorial island coral reefs
|Contact: Cheryl Dybas|
National Science Foundation