KING TIDES IN
SOUTHERN
CALIFORNIA
“King” or peak extreme high tides appear on our coast twice per month and twice per
year - winter and summer - when the earth, moon, and sun are specially aligned.
Scripps Institution
of Oceanography
King Tide Pier Walk
19 February 2015
San Clemente Pier, January 1983
Why care about King Tides?
Water levels on our coast are mainly a combination of mean sea level, and the fluctuating tides
and uprush of breaking waves in the surfzone, each reaching 2-3 feet.
Storm surges from low barometric pressure and wind can raise sea level up to ½ foot more for a
few hours or days. Periodically, El Niño increases sea level by up to another few tenths of a foot
for a year or two at a time.
Coastal erosion, flooding, and damages occur in California when storm waves and surges and
El Niños conditions coincide with peak high “King” tides.
Future mean sea level rise is expected to gradually make coastal erosion, flooding, and damages
from these forces progressively worse and more frequent.
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King Tides in Southern California
"King Tides" are peak or extreme high tides that in
California occur twice per month and twice per year.
Definitions of recurrence are fuzzy and may vary.
Winter 2014-15 monthly peak high tides
La Jolla Scripps Pier
2014-2015
Heights
(ft MLLW)
Times
Oct 9, 25
6.3, 5.9
10:00, 10:02
Nov 6, 23
6.5, 6.3
07:56, 06:26
Dec 6, 22
6.3, 6.5
08:11, 08:29
Jan 3, 20
6.1, 6.6
07:25, 08:21
Feb 2, 18
5.7, 6.4
07:50, 08:12
Mar 3, 19
5.2, 5.8
07:38, 09:03
The monthly and yearly patterns result from the
regional ocean response to the tide generating
forces of the moon and sun on the earth (Fig 1).
Southern California has a mixed-tide regime. This
means about two-thirds of the tide height is made
up of semi-diurnal (twice-daily) tides, and one-third
from diurnal (once-a-day) parts.
California is distinct from the US east coast, which is
dominated by semi-diurnal tides with totally
different King Tide patterns.
King Tides in California are formed when large,
twice-per-month semi-diurnal spring tides at new
moon and full moon (Fig 2) and large diurnal tropic
tides from high lunar and solar declination (north
and south height in the sky, Fig 3) coincide (Fig. 4).
Perigee (nearness to the moon) also produces bigger
semi-diurnal tides. But it doesn’t influence our twicea-year pattern, since that's determined by the solar
declination.
Lunar declination also peaks twice-per-month.
Summer and winter solar declination defines the
seasons and sets our peak tide patterns. The highest
monthly tides happen on winter mornings and
summer evenings (Fig 5).
The peak tide time-of-day pattern has consequences
for winter storm preparation, which often occur at
night in anticipation of the morning high tide. But,
inter-tidal species can live higher up in the water
column as the afternoon maximum high tides help
avoid desiccation from the summer sun.
California peak tides are properly called tropic-spring
high tides. They are not perigean springs, which
dominate the east coast.
Other tide oscillations arise from subtle orbital
fluctuations of the moon that introduce smaller yet
important changes in the peak tides on our coast at
4.4 and 18.6-year intervals (Fig. 6).
Figs 1-4 are some excellent illustrations of the earthmoon-sun astronomical relationships that produce
King Tides from the U-T San Diego:
https://www.utsandiego.com/photos/galleries/2013
/jan/10/understanding-king-tides/.
Sea level rise will become ever-more critical to coastal flooding, erosion, and infrastructure damages
later this century (Fig. 7). Maximum water levels now rare will occur with increasing frequency (Fig 8).
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Figure 1. Tides are caused by the gravitational interaction of the Earth, Moon, and Sun.
Figure 2. Semi-diurnal tides peak when Earth, Moon, and Sun are lined up at full and new Moon.
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Figure 3. Diurnal tides peak when Moon and Sun are farthest north or south.
Figure 4. King Tides are the twice-per-month and twice-per-year combination of these effects.
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Figure 5. Peak monthly high tides occur in the morning in winter and evening in summer. (La Jolla)
Figure 6. Predicted monthly maximum high tides vary over 4.4 and 18.6 year cycles. (La Jolla)
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Figure 7. Yearly average mean sea level – Overall rise is about 2 mm/yr. (La Jolla)
Figure 8. Observed (points) and projected (lines) monthly maximum water levels. (San Diego)
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Suggested Reading
Books:
Cabrillo National Monument Foundation, 2004. Understanding the Life of Point Loma, Cabrillo National Monument
Foundation, San Diego, CA, 184 pp, ISBN-13: 978-0941032087
Griggs, G., K. Patsch, and L. Savoy (Editors), 2005. Living with the Changing California Coast, University of California
Press, Berkeley, CA, 551 pp, ISBN: 978-0520244474.
National Research Council, 2012. Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past,
Present, and Future, National Academy Press, Washington D.C, 201 pp.
Technical Papers:
Bromirski, P.D., A.J. Miller, R.E. Flick, and G. Auad, 2011. Dynamical Suppression of Sea Level Rise Along the Pacific
Coast of North America: Indications for Imminent Acceleration, Jour. Geophys. Res. C., 116, C07005.
Bromirski, P.D., A.J. Miller, and R.E. Flick, 2012. North Pacific Sea Level Trends, Eos Trans. AGU, 93(27).
Flick, R.E., 1998. Comparison of California Tides, Storm Surges, and Sea Level During the El Niño Winters of 1982-83
and 1997-98, Shore & Beach, 66(3).
Flick, R.E., 2000. Time-of-Day of Peak Tides in a Mixed-Tide Regime, Shore & Beach, 68(4).
Flick, R.E. and A. Badan-Dangon, 1989. Coastal Sea Levels During the January 1988 Storm off the Californias, Shore
& Beach, 57(4).
Flick, R.E. and D.R. Cayan, 1984. Extreme Sea Levels on the Coast of California, Proc. 19th Int. Conf. Coastal Eng.,
Amer. Soc. Civil Eng.
Sweet, W.V. and J. Park, 2014. From the extreme to the mean: Acceleration and tipping points of coastal
inundation from sea level rise, Earth’s Future, 2, doi:10.1002/2014EF000272.
Zetler, B.D. and R.E. Flick, 1985. Predicted Extreme High Tides for California, 1983-2000, Jour. Waterway Port,
Coastal and Ocean Eng., Amer. Soc. Civil Eng., 111(4).
Zetler, B.D. and R.E. Flick, 1985. Predicted Extreme High Tides for Mixed-Tide Regimes, Jour. Phys. Oceanog., 15(3).
Websites:
California King Tides Project – http://california.kingtides.net/
National Oceanic and Atmospheric Administration (NOAA) – Source of official U.S. tide predictions and water level
information - http://tidesandcurrents.noaa.gov/