Sea Level Confusion

Mean sea level confuses me.   Intuitively I want sea level to be the same all over the world.  But it isn’t.   One reason the Panama Canal has locks, sea level on the Pacific side averages 8 inches higher than on the Atlantic side….and the tides are higher on the Pacific side too.   Without the locks, water would constantly be flowing from the Pacific side to the Atlantic side.

And sea level is not changing at the same rate all around the world.  Some places have a rising sea level, others falling.   Supposedly worldwide sea level is rising steadily as demonstrated by this chart courtesy of the Australian government:

Plot of global sea level from 1993 to 2012

NOAA keeps data for all the 50 states of the USA and that data generally shows a much slower rise….and in some cases no rise since 1990.  Something doesn’t make sense…and that confuses me.  Let’s begin looking at NOAA data for San Francisco.   The data for San Francisco is some of the oldest available.  It goes back over 150 years.  Here is the sea level data chart for San Francisco:

chart: Mean Sea Level Trend, 9414290 - San Francisco, California

San Francisco peaked in 1998 (a strong El Nino year).  NOAA also provides charts that show the change year to year.   They call these charts interannual charts.  Here is the interannual chart for San Francisco.residual1980.png

Since 1998 sea level is San Francisco has been going down.   How about Miami Beach Florida:

residual.png

Miami appears to have peaked in the 1940’s?   But the data shows no real net change in the 50 years the data has been kept.  NOAA must have changed where they keep data for this area as the data stops in the 1980’s.  But the data is interesting as it shows variations that should have predated man caused climate change.  The data does not match the San Francisco data.   It has less overall movement and it peaks at a different time. Now lets see how the Pacific Ocean has been doing by taking a peak at Honolulu, Hawaii:

chart: Mean Sea Level Trend, 1612340 - Honolulu, Hawaii

Honolulu has been rising, but slowly.  It looks a lot like San Francisco.  Let’s zoom in on the data since 1990 by looking at interannual variation chart .

residual1980.png

The change since 1990 has been minimal.  The area above the zero line on the chart roughly equals the area below the line.

Are you confused yet?  Now let’s look at data for Seward, Alaska:

chart: Mean Sea Level Trend, 9455090 - Seward, Alaska

An earthquake in 1964 is probably the reason for the shift in data.  The Seward waterfront was devastated by a tidal wave following the Good Friday Earthquake on March 28th 1964.  The trend of the data is …down.  Sea level has been going down in Seward since at least 1964.    How can that be?  If the worldwide sea level has been rising steadily since 1990, how can it be going down in Seward?  The NOAA data appears to contradict the Australia data?

Now let’s look at Juneau, Alaska.  Are you ready…this one’s really weird:

chart: Mean Sea Level Trend, 9452210 - Juneau, Alaska

Juneau makes no sense to me at all.   The world has been warming, glaciers have been melting.  Sea level should be going up world wide.   I have no reason not to believe the data provided by NOAA.  After all they are pretty good at this stuff.

Climate activists have been talking global disaster for years and years.  One really big disaster has been a rapidly rising sea level.   Al Gore featured it in his 2006 film, An Inconvenient Truth.   The UN’s Intergovernmental Panel on Climate Change (IPCC) has been making claims in advance of the 2014 release of their AR5 climate assessment.   Sea level rise has made the news as this link to an article in the Yale forum on Climate Change and the Media demonstrates.  Here is a chart prepared by the IPCC from that article:

I suspect guessing.  Wild Ass Guessing!  AND I am confused.

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