I’ve moved to WordPress: http://bobtisdale.wordpress.com/

Sunday, July 19, 2009

Sea Level Update - Through March 2009

I’ve moved to WordPress.  This post can now be found at Sea Level Update – Through March 2009

This post presents graphs of raw, smoothed, and annualized sea level data for Global, Indian Ocean, Atlantic Ocean, and Pacific Ocean data sets. The recently updated data is available through the University of Colorado at Boulder. Here’s a link to their Sea Level Change Overview (index) webpage:
and a link to their Time Series Data Page:

Note 1: You’ll note the graphs of the raw and smoothed data include the notation “Smoothed w/ 35-Period Filter”. The number of samplings varies per year, from 35 one year to 38 the next for example. Keep that in mind when viewing the data. To assure that the smoothing did not misrepresent the data, I’ve also presented the annual mean of the data sets in separate graphs from 1993 to 2008.

Note 2: All of the data sets include the seasonal signals and they exclude the inverted-barometer adjustments.


Figure 1 shows the Global Sea Level for the period of December 1992 to March 2009. Global Sea Level appears to have risen at a reasonably constant rate until mid-2005, when the rate of rise decreased.
Figure 1

Looking at the annual data from 1993 to 2008, Figure 2, confirms the sharp deceleration in the rise of Global Sea Level in 2006 through 2008.
Figure 2


The Indian Ocean Sea Level data is shown in Figure 3. Based on the smoothed data, the Indian Ocean Sea Level remained flat from early 2007 to early 2008, then rose again since then. Also note the multiple swings in sea level during 1996 and 1997, leading up to the El Nino of 1997/98.
Figure 3

Figure 4 illustrates the annual Indian Ocean Sea Level from 1993 to 2008. The rate at which Indian Ocean Sea Level was rising (appears to have been increasing exponentially) finally slowed in 2008.
Figure 4


The raw sea level data for the Atlantic Ocean is illustrated in Figure 5. Based on the smoothed data , the Atlantic Ocean Sea Level does not appear to have risen since 2005.
Figure 5

The annual Atlantic Ocean Sea Level data confirms this. Refer to Figure 6. Atlantic Ocean Sea Levels remained flat in 2006, dropped in 2007, then rose slightly in 2008, but 2008 levels are still lower than those in 2005 and 2006.
Figure 6


The smoothed sea level data for the Pacific Ocean, Figure 7, also appears to have flattened and decreased in recent years.
Figure 7

Figure 8 illustrates the annual Pacific Ocean Sea Level data from 1993 to 2008. Pacific Ocean Sea Levels in 2008 are lower than they were in 2004.
Figure 8


Figures 9 and 10 are comparison graphs of Atlantic, Indian, and Pacific Ocean Sea Level data. In Figure 9, that data is annual, and in Figure 10, it has been smoothed with a 35-month filter.
Figure 9
Figure 10


Frank Kotler said...

Thanks, Bob, for "scrambling" to get this site updated! Nice complement to the WUWT post. I notice a "dip" - timing varies, but roughly "just before the big El Nino". Do we know/speculate a reason for that? I don't know what it all means, but "food for thought". Thanks for the meal! :)


Bob Tisdale said...

Frank Kotler: Give me a day or two. I want to convert the Sea Level data to monthly data then compare it to NINO3.4 SST anomalies. It'll probably be a new post.

Anonymous said...

Whay could be the cause of this slowdown?

It could not be a slowdown of glacier melt. In Greenland there had been RECORD MELT in 2007. I dont't know the Antartic data, but given the strong warm anomalies of last years plus the fallout of the recent Antarctic Peninsula ice shelf disintegrations, probably there was record melt here too.

Maybe the ENSO pattern of the last 3 yers,or something else in oceanic circulation. Or even some tectonic reshaping of the ocean floor ?

Bob Tisdale said...

Anonymous: Sea Surface Tempeatures had been dropping since 2005 (There's been an upswing over the past few months, which hasn't registered in the sea level data yet). The drop in SST is the likely cause.

Anonymous said...

Bob Tisdale: Thank you for the idea.

It would be nice to put the regional SST anomalies and the sea level rise in the same graph to see the relationship between both.

Bob Tisdale said...

Anonymous: I'm considering comparing Sea Level and SST in a future post. But there are other things to do before that one.


Tips are now being accepted.

Comment Policy, SST Posts, and Notes

Comments that are political in nature or that have nothing to do with the post will be deleted.
The Smith and Reynolds SST Posts DOES NOT LIST ALL SST POSTS. I stopped using ERSST.v2 data for SST when NOAA deleted it from NOMADS early in 2009.

Please use the search feature in the upper left-hand corner of the page for posts on specific subjects.
NOTE: I’ve discovered that some of the links to older posts provide blank pages. While it’s possible to access that post by scrolling through the history, that’s time consuming. There’s a quick fix for the problem, so if you run into an absent post, please advise me. Thanks.
If you use the graphs, please cite or link to the address of the blog post or this website.