Friday, May 6, 2011

A dilemma explained, maybe

For some reason, as global sea levels have been rising slowly, due to both melting and thermal expansion of seawater, the U.S. West Coast has not seen a corresponding rise. Now a new study explains why, and also indicates that the grace period may be ending. This is not good news for surfers as a higher sea level will move the wave-breaking zone!

Climate Shift May Accelerate West Coast Sea Level Rise

The reason is the phase of the Pacific Decadal Oscillation. The strange thing about this article is that it talks about the PDO being in the process of switching from the warm to the cool phase; I thought that had definitively happened a couple of years ago, signaled by the previous La Nina event to this one. Hmmmm...

"Right now, it looks like the patterns in the wind stress over the North Pacific are in the process of going from the prevailing pattern that has occurred since the mid-'70s to the one that was occurring before that," said the new study's lead author, geophysical oceanographer Peter Bromirski of the Scripps Institution of Oceanography.

It's that change that could affect sea level rise along California and the rest of the United States' Pacific Coast, the new study finds.

Based on their analysis of wind stress patterns and data collected by tide gauges, Bromirski and his colleagues conclude that the PDO's current warm phase has suppressed sea level rise along the West Coast during the past three decades."

No comments: