Southern California King Tides in 2017/2018

Southern California King Tides in 2017/2018

The winter King Tides for Southern California are in early December and January. At Balboa Pier, Newport Beach, they will occur at the following dates and times, with associated heights above relative mean sea level.


Dec. 2….7.18 AM……6.5 ft

Dec. 3….7:57 AM……6.8 ft

Dec. 4….8:39 AM……6.8 ft

Dec. 5….9:24 AM……6.6 ft

Jan. 1…..7:42 AM……6.8 ft

Jan. 2…..8:28 AM……6.9 ft

Jan. 3…..9:15 AM……6.7 ft

These high tides are as much as 2.8 feet above the evening high tides.

A teachable lesson is that the present day King Tides give an impression of where normal high tides will be 50 years from now due to sea level rise from global warming. The warming melts glaciers and landed ice packs in Greenland and Antarctica. Also, when the 95% of the warmth goes into the ocean, it heats and expands the oceans.

It is much more important to emphasize that the water damage will not come from the creeping sea level rise, but from storms with high tides, and storm surges plus high storm waves.  There may also be overflowing rivers and canyons from extreme Pineapple Express rainfalls, and perhaps extra El Niño sea level rise from warmer waters and winds from the West.

The NOAA website gives the data that nearly 200,000 Californians live in low-lying coastal areas lower than one foot below sea level. 873 miles of coastal roads are at hazard from King Tides or storm surges. Coastal tourism accounts for 39% of California’s $17.6 billion coastal economy. Floods could interfere with transport to jobs accounting for $662 billion in wages and $1.7 trillion in GDP.

A Government Accounting Office study projected that heavy rains and rising sea level could increase flood losses in coastal communities in the US by $23 billion per year by 2050.

Part of the King Tides comes from the fact that the earth is in an elliptical orbit, with the sun at one of the ellipse’s foci. The earth is at the closest point to the sun (the perihelion) around January 2.

The normal tides point to and away from the moon as the earth and its oceans daily rotate completely around. The moon rotates around the earth in its own elliptical orbit every 29 days. Tides are highest when the moon is at its closest point to the earth, or perigee.

Near when perihelion occurs, when the moon’s perigee occurs and the moon is aligned between the earth and the sun, the highest tides occur.

Tides are extremely complicated. On earth, they depend on the uneven depth of the ocean, the continents pushing the oceans around as the earth rotates, ocean currents, weather, which side of the earth is closest to the moon, centrifugal force from the earth’s rotation, and location, location, location. The moon’s orbit is also variable in distance around the ellipse, there is the precession of the ellipse, the 5 degree tilt of the moon’s orbit, the relative location of the sun, and other effects. The tides depend on the declination of the sun and the moon, and the season, due to the tilt of the earth’s axis.

Despite this complexity, some sealife reproduction is timed to high tides and certain full moons, such as coral reproduction, turtle egg laying, and grunion reproduction. It behooves us to maintain beaches for the other species on the earth, besides just for ourselves.



About Dennis SILVERMAN

I am a retired Professor of Physics and Astronomy at U C Irvine. For a decade I have been active in learning about energy and the environment, and in lecturing and attending classes at the Osher Lifelong Learning Institute (OLLI) at UC Irvine.
This entry was posted in California Water, Climate Change, Climate Science, Coastal Flooding, King Tides, NOAA, Sea Level Rise. Bookmark the permalink.

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