SOUTH PACIFIC SEA LEVEL: A REASSESSMENT
by Vincent R. Gray | August 16, 2010
ABSTRACT
The SEAFRAME sea-level study on 12 Pacific islands is the most comprehensive study of sea level and local climate ever carried out there. The sea level records obtained have all been assessed by the anonymous authors of the official reports as indicating positive trends in sea level over all 12 Pacific Islands involved since the study began in 1993 until the latest report in June 2010. In almost all cases the positive upward trends depend almost exclusively on the depression of the ocean in 1997 and 1998 caused by two tropical cyclones. If these and other similar disturbances are ignored, almost all of the islands have shown negligible change in sea level from 1993 to 2010, particularly after the installation of GPS levelling equipment in 2000.

http://scienceandpublicpolicy.org/images/stories/papers/originals/southpacific.pdf

Auckland: A Case Study in the Regional Assessment of Long-Term Sea Level Change

John HANNAH, Rob BELL and Ryan PAULIK, 2011

http://77.243.131.160/pub/fig2011/papers/ts07i/ts07i_hannah_bell_et_al_4854.pdf

THE GREAT SEA-LEVEL HUMBUG
There Is No Alarming Sea Level Rise!

http://www.21stcenturysciencetech.com/Articles_2011/Winter-2010/Morner.pdf

The pdf at nzclimatescience wouldn’t save to disk for some reason.

http://joannenova.com.au/2011/07/australian-sea-levels-are-not-accelerating/comment-page-2/#comment-407635

My contribution (after consultation with a couple of helpful CCG guys):-

75
Richard C (NZ):
July 25th, 2011 at 6:29 pm

Thanks Ross # 25 for the Axel Morner article, it’s been a while since I’ve looked at the issues in it but revisiting them in the light of what I’ve learned since makes it all the more relevant.

The TOPEX/Jason satellite data also has a deceleration, it’s very easy to pull down the data and fit a 3rd order polynomial to show it. The problem is the difference in linear trends between globally averaged tide guage data and the satellite trend of TOPEX/Jason (Envisat is less). The “adjustments” to satellite data documented by Axel Morner are incriminating, without which the satellite era data would show no rise. Axel Morner explains:-

As reported above regarding such adjustments, an IPCC member told me that “We had to do so, otherwise it would not be any trend,”

Re Tamino. A curve fitting exercise like his will show both recent acceleration and deceleration in individual tide guage data but they are very small and so what? It’s the global aggregate that matters. The required rates of global acceleration for any levels above normal (18mm/decade tide guage, 31mm/decade satellite) are just not evident recently. Houston and Dean refute Rahmsdorf and Vermmeer saying they “are curve fitting, not modeling physics, so the approach cannot be used to predict future sea level”. Even the IPCC has discounted the R & V proposition for the lack of physical relationships.

The other problem I see is that once a model has been fitted e.g. Tamino’s, the apparently “better” correlation is then projected into the future with alarming connotations e.g. Tamino. This ignores the bigger picture (OHC stalled since 2003/04, clouds, grand solar minimum prediction etc) where there isn’t the drivers to continue the projection.

The important point I think is the H & D conclusion:-

“The important conclusion of our study is not that the data sets we analyze display small sea-level decelerations, but that accelerations, whether negative or positive (we reference studies that found small positive accelerations), are quite small. To reach the multimeter levels projected for 2100 by RV requires large positive accelerations that are one to two orders of magnitude greater than those yet observed in sea-level data.”

Reply to: Rahmstorf, S. and Vermeer, M., 2011. Discussion of: Houston, J.R. and Dean, R.G., 2011.

http://www.jcronline.org/doi/full/10.2112/JCOASTRES-D-11A-00008.1

Re the Auckland tide guage series. Folks here may be interested in this paper:-

Auckland: A Case Study in the Regional Assessment of Long-Term Sea Level Change
John HANNAH, Rob BELL and Ryan PAULIK, 2011

http://www.climateconversation.wordshine.co.nz/docs/an-updated-analysis-of-long-term-sea-level-change-in-nz-jhannah-2003.pdf

It puts Auckland in broad perspective including millennial and global, also cites Watson 2011.

How Not to Analyze Tide Gauge Data

http://tamino.wordpress.com/2011/07/22/how-not-to-analyze-tide-gauge-data/

I’m inclined to agree that the Watson analysis is very poor. Tamino dissects Fremantle and finds acceleration from (approx) 1897 – 1927, deceleration 1927 – 1975 and acceleration 1975 – 2009. I doubt that a Loess smoothing for Auckland would return a similar acceleration to Fremantle due to falling levels 2000 -2009 (Fremantle rising over that period) but might still be a recent acceleration. I haven’t got a link to the Auckland data source but Hannah 2010 is referred to by Hannah, Bell, Paulik 2010.

The Tamino method for identifying acceleration by time derivative of a quartic model is very interesting:-

a = 2 \beta_2 + 6 \beta_3 t + 12 \beta_4 t^2. (see the blog post for this).

Fremantle data here:-

http://www.psmsl.org/data/obtaining/stations/111.php

It comes as absolute values above a datum, Tamino has plotted an anomaly but doesn’t give the baseline but I assume it’s the entire series. Then he computes a second anomaly to remove the annual cycle then smooths with Loess. which is surely better (?) than Watson’s moving average.

Auckland (Hannah, Bell, Paulik 2011) here:-

http://77.243.131.160/pub/fig2011/papers/ts07i/ts07i_hannah_bell_et_al_4854.pdf

What’s has got my attention is Tamino’s method of deriving instantaneous acceleration which is different to looking for a departure from a long-term trend that I’ve been looking for. I haven’t looked at the local tide guage data in this light, I’ve mainly been looking at the global satellite trend using a 3rd order polynomial (Loess might be better) which seems a good fit to my unskilled eye. It’s easy then to eyeball approximate instantaneous rates.

Andy, you’re the mathematician. Bob, Gary, You guys have stats knowledge that I haven’t – any comments on the Tamino post?

http://www.flickr.com/photos/scrase/5633268015/in/photostream

Bad news for the Pleasant Point Yacht club. The building is stuffed and sinking into the swamp.

If Tuvalu looks after its coral it should be OK.

Hemi McK

Both.

The paper describes “Short period trends of acceleration in mean sea level after 1990″. During the first half of the 90s, cloud cover (mainly low-level) did decrease (low-level cloud is not modeled) allowing an insolation increase at the sea surface, the result being increased ocean heat and thermal expansion which shows up as the short periods of sea level rise acceleration. Svensmark explains the cloud cover change as the solar wind modulated cosmic ray effect..

This is a hugely important phenomenon and one in which the IPCC has been negligent. See:-

Reflected Sunlight Shines on IPCC Deceptions and Inadequacies

http://www.fcpp.org/publication.php/3404

Figure 3: Global Albedo change 1984 – 2004 shows the effect of cloud cover change and solar energy flux.

“The moon’s albedo is 7, which means 93 units of 100 are absorbed and 7 units reflected. Earth’s albedo is 30 on average for the entire globe. The amount varies from a high of 75 to 95 percent for fresh snow down to 8 or 9 percent for coniferous forest. Seasonal variation in snow and ice cover is important as it affects global energy and therefore the weather from year to year. However, the major factor is variability in the type and amount of cloud cover. Thick cloud varies from 60 to 90 and thin cloud from 30 to 50. This variability explains most of the change in albedo shown in Figure 3. The right side scale shows changes in energy with a range of about 9 watts per square meter. Compare this with the 2.5 watts per square meter change estimated to be due to human activities.”

The next section deals with IPCC inadequacy in regard to natural forcings. AR4 Figure 4 Table of Radiative Forcings has only one forcing in the Natural Category – TSI (Total Solar Irradiance). As Tim Ball writes:-

“IPCC reject irradiance as a cause of temperature change since 1950, but they also reject variations in sun/earth relationships, known as the Milankovitch Effect and the relationship between sunspots and temperature hypothesized by the Svensmark Cosmic Theory. The latter shows a relationship between changes in solar magnetism evidenced by sunspots. As the magnetism varies it determines the amount of galactic cosmic radiation reaching the Earth, which creates low cloud. As low cloud varies albedo varies.

The Earthshine project of the California Institute of Technology that produced Figure 3 concluded in 2004. “Earth’s average albedo is not constant from one year to the next; it also changes over decadal timescales. The computer models currently used to study the climate system do not show such large decadal-scale variability of the albedo.” Sadly, there are many factors affecting climate change that the IPCC ignore or underplay to achieve the political result that human CO2 is the sole cause.”

“Is There Evidence Yet of Acceleration in Mean Sea Level Rise around Mainland Australia? ”

That the answer is no, in spite of “a projected global rise in mean sea level of up to 100 cm over the 21st century” seems to be very difficult to admit and the author may even be disappointed that one of the “multiple lines of evidence” is just not meeting expectations. It’s as if accelerating sea level rise is a fait accompli and it’s just a matter of time before it kicks in (but not “yet”).

There are now less than 90 years left of the 21st century for the projected rise to occur but if the deceleration of 0.02-0.04 mm/year/year continues then the 2100 rate can be calculated using the average initial velocity (Vi) of the 1920-2000 rise which was 120/80 = 1.5mm/year (current global satellite 3.1mm/year). by substituting in a = (Vf – Vi)/t.

http://www.physicstutorials.org/home/mechanics/1d-kinematics/acceleration

After 50 years (2060)

-0.03 = (Vf – 1.5)/50

Vf = 0mm/year

After 90 years (2100)

-0.03 = (Vf -1.5)/90

Vf = -1.2mm/year

So now Barbara Dreaver can breathlessly announce that by 2060 sea levels in the vicinity of Australia and New Zealand will have stopped rising and by 2100 will be falling at -1.2mm per year – a good news scoop for TV1.

Bryan Walker at Hot Topic can stop writing 3 hanky weepies about the poor folks of the Pacific low-lying islands that were sure to be inundated and instead break the joyful news to his loyal readers that the latest science indicates a wonderful reprieve.

The Royal Society of New Zealand will rush these findings post haste to the PM’s climate change adviser Sir Peter Gluckman who will immediately brief the PM and the Minister of Climate Change so that govt departments and the people of NZ are informed of this amazing turnaround from predictions and we can all celebrate the let-off from catastrophe .

It’s just a warm fuzzy feel good story all around.

…..Yeah….Right.