Fig. 1 Dredd Blog Model Zones |
I. Background
I had a difficult time deciding which series to put this post into.
Should it be in "The Evolution of Models" or in "Questionable 'Scientific' Papers" I wondered.
I finally made the decision to post it in this series, because scientific professionals just keep filing papers based on an old error about thermal expansion that causes sea level rise (SLR).
"The thermal expansion trance has got to go," I thought, so suppressing my intimidation at
Fig. 2 Typical Tide Gauge sea level rise data |
To get right to it, first notice Fig. 2 and Fig. 3 for the purpose of grasping the gist of the story.
The zone those graphs focus on (AH.SE.NW see Fig. 1) has the following tide gauge
Fig. 3 Proportions of SLC |
II. The Point
Basically, thermal expansion cannot account for the PSMSL data we see a lot here on Dredd Blog.
The overuse of thermal expansion is akin to other old "problems" some in the scientific community toiled with for years, such as "the tide gauge station problem" and "the European problem," neither of which were the problem.
Fig. 4 |
The graph in Fig. 3 shows three contributors: "displacement, ghost-water, and thermal expansion."
Their percentage of contribution now in the model, is 80.95% for "displacement," 13.95 percent for "ghost-water," and 5.1% for "thermal expansion."
Displacement is what happens when melt water flows from the land into the ocean, or ice bergs calve off glaciers and then fall into the ocean.
The ghost-water phenomenon was explained recently in the Dredd Blog post The Ghost-Water Constant.
Thermal expansion, the current fettish driving a lot of error, is talked and written about all the time, such as:
"we note that a warming of 1°C over the central 200 m of the Atlantic layer [in the Arctic Ocean] would result in a local rise of steric sea level of 10 to 20 mmThese are all competent scientists who are laboring without first considering all of the relevant evidence available, and thus improperly attributing quantities of SLC to thermal expansion.
[1-2 cm]" - IPCC
Fig. 5
"For the period 1985–2025 the estimate of greenhouse-gas-induced warming is 0.6–1.0° C. The concomitant oceanic thermal expansion would raise sea level by 4–8 cm [40-80 mm]." - Thermal expansion of sea water associated with global warming
"The amount of sea level rise that comes from the oceans warming and expanding has been underestimated, and could be about twice as much as previously calculated, German researchers have said." - Sea level rise from ocean warming underestimated
III. The Reality
The link to the IPCC page, in Section II above, also says "... thermal expansion ... is one of the major contributors to sea level changes during the 20th and 21st centuries" (notice that Fig. 3 lists it as the least of three factors).
Fig. 6 |
"Water is essentially incompressible, especially under normal conditions" (USGS), and its expansion is not sufficient to account for the degree of SLR being observed (Engineering Toolbox).
There is indisputable sea level fall (SLF) that thermal expansion cannot explain, because that SLF is not thermal, or any other type of compression for that matter.
Fig. 7 |
Those posts show that sea level began to fall in the late 1700's because of the two main factors in SLC: displacement and ghost-water.
That dynamic is still ongoing now.
The zone AH.SE.NE contains large population centers, which the century of tide gauge station records show, is experiencing SLR (Fig. 6, Fig. 7)..
The tide gauge stations there are: #1158 (YARMOUTH), #96 (HALIFAX), #1153 (CAPE
Fig. 8 Sub-zones of Zones @ Fig. 1 |
IV. Possible Sources of the Thermal Error
The lack of familiarity with the ice sheet gravity dynamics, which Dr. Mitrovica (video below) lectures about, is an obvious source of this ongoing inaccuracy.
Another source is that some scientists ever so often "detect" more SLR than the historical thermal expansion values would account for.
Their recent and naive doubling of those values, without sufficient evidence IMO, is a case in point (Sea level rise from ocean warming underestimated).
That said, I also may have to adjust "the ghost-water constant" (13.95%), if more accurate lengths of the coastlines of Antarctica and/or Greenland are found (The Ghost-Water Constant).
And perhaps the 5.1% for thermal expansion could be adjusted a bit.
Yet, I am fine with the principles involved in this hypothesis.
V. Conclusion
Let me know your opinions on this.
The graphs in Fig. 4 and Fig. 5 are from zone AH.SE.SW, which means that today's examples are from the U.S. East Coast and N.W. Florida.
Zone AH.SE.SW contains stations: #1156 (DAUPHIN ISLAND), #246 (PENSACOLA), #1641 (PANAMA CITY @ ST.ANDREWS BAY @ FL), #112 (FERNANDINA BEACH), #395 (FORT PULASKI), #234 (CHARLESTON I), #1444 (SPRINGMAID PIER), #396 (WILMINGTON SC), #1636 (DUCK PIER OUTSIDE), #1635 (CHESAPEAKE BAY BR. TUN.), #299 (SEWELLS POINT @ HAMPTON ROADS), and #636 (KIPTOPEKE BEACH).
Those zones are on the map above (Zone In On Sea Level Change).
The next post in this series is here, the previous post in this series is here.
Dr. Mitrovica: A discussion of, among other things, SLC as impacted by ice sheet mass and gravity:
Thanks Dredd! Great work! I'm happy to leave the calcs to you and the Cray-1 to establish the source and contribution of the 'inputs' in the lab. Meanwhile, I'll try and keep tabs on what is currently happening out in the 'field'.
ReplyDeleteOh my!
http://www.huffingtonpost.com.au/entry/pacifica-cliff-collapse_us_56a6d5a8e4b01a3ed123bd2f?section=australia
Mark,
DeleteLOL. I guess, then, that I am stuck here in the Crayosphere with the Memphis Blues again.
That some few in the scientific community are not as aware as they should be is unfortunate.
ReplyDeleteBut, in general the sea level scientists like Rignot, Hansen, and Mitrovica are spot on.