The morning of Thanksgiving Day was a “King Tide” day. King Tide is a colloquial term for an unusually high tide. These occur when the sun and moon are aligned, the moon is closest to the earth, and the earth is closest to the sun. All three factors intensify the gravitational pull that makes the tides.
I have been attending meetings of the Del Mar Sea Level Rise Technical Advisory Committee, which is working on an LCP Amendment to address sea level rise. Encinitas has a City Council Subcommittee, slowly getting started on planning an LCP amendment for the same purpose. I thought some pictures at King Tide might help people visualize the impact of sea level rise on our coastal lagoons.
That is the stated purpose of the King Tides Initiative – to show a preview of what the “normal” high tides will look like as sea level creep up.
I decided to go out for a tour and get some pictures. At about the peak of high tide, I visited two coastal lagoons near me: the San Elijo Lagoon http://www.sanelijo.org in Encinitas and the San Dieguito Lagoon in Del Mar. You can see the results on my Flickr page or the San Diego King Tide Flickr Group.
The picture above is the Boardwalk at the Del Mar Fairgrounds. It was the subject of a controversy last March. The Commission denied a request for a permit amendment to leave the boardwalk in place. The original plan had been to remove it completely. The issue was resolved by a compromise – some of it will be removed, but the part shown above will remain (until nature has the final say, with another foot of sea level rise). Here is a view of the same section at a “normal” tide level.
This year, the King Tides are getting an extra boost. Three factors are increasing the heights of the highest tides: thermal warming of the oceans due to climate change, more thermal warming from the big pool of warmer water off the California coast, and prevailing winds pushing water up against our coast. The results show up on tide gauges. Here is a clip from the NOAA tide guage at La Jolla for November 26.
The blue line is predicted sea level, the red line is observed level, and the purple line shows the excess of actual over predicted. It shows that the actual levels are running almost a foot above what was predicted based on historical tide records.
The first King Tides in the 2015-2016 season were on November 24th to 26th. There are two more coming: December 22nd to 23rd, and January 21st and 22nd, 2016. Check out the International and California King Tides Initiative web sites, and plan to get some pictures in your area.