|Fig. 1 Why is my sea level rise not the same as yours?|
IMO Dredd Blog readers are those who are not afraid to consider "WHY."
Nevertheless, some of those readers may wonder if "ghost water" is a sufficiently scientific way of describing the phenomena of "the missing cause" (The Ghost-Water Constant, 2, 3, 4, 5, 6, 7).
Other readers may wonder if there is even such a thing as a missing cause as has been described, hypothesized, and detailed in this Dredd Blog series.
Today, I will give more credence to the dynamics we describe as "sea level rise" (SLR), "sea level fall" (SLF), or the combined way of describing both SLR and SLF, which is "sea level change" (SLC).
In doing so, I will use a paper from one of the IPCC authors, Professor Nathan Bindoff, which (IMO) gives me sufficient cred to "make it so."
IMO, that author is a sufficient authoritative source:
Professor Bindoff was the coordinating lead author on the oceans chapter in the fourth IPCC assessment report and the detection and attribution chapter in the fifth IPCC report. He was awarded a certificate for his contribution to the IPCC and [along with] Al Gore winning the Nobel Peace Prize in 2007. The 2007 report marked the turning point in discussion on climate change globally.(U. of Tasmania). We will focus on some of the written sections of a published paper, which has ended up being cited as "Bindoff et al. 2007" (PDF).
Here are some of the quotes and issues from that paper which we will consider in today's post:
(Bindoff et al. 2007, Executive Summary, p. 387). I will argue today, as I have in other places in this and other Dredd Blog series, that the missing "processes causing sea level rise" (section III. [D.]) is called "ghost water," because like gravity it is invisible, especially when one is not looking for it.
"Sea level change is highly non-uniform spatially, and in some regions, rates are up to several times the global mean rise, while in other regions sea level is falling."
"The oceans are warming. Over the period 1961 to 2003, global ocean temperature has risen by 0.10°C from the surface to a depth of 700 m."
Table 5.3, p. 419
"As reported in the TAR, it is likely that the sum of all known contributions for this period is smaller than the observed sea level rise, and therefore it is not possible to satisfactorily account for the processes causing sea level rise."
Professor Mitrovica (who is quoted in Bindoff et al. 2007 in terms of land uplift when glaciers recede) pointed out the first paper to identify the likelihood of ghost water, citing to that paper as "Woodward 1888":
"To our knowledge, Woodward (1888) was the first to demonstrate that the rapid melting of an ice sheet would lead to a geographically variable sea level change. Woodward (1888) assumed a rigid, non-rotating Earth, and therefore self-gravitation of the surface load was the only contributor to the predicted departure from a geographically uniform (i.e. eustatic) sea level rise. This departure was large and counter-intuitive. Specifically, sea level was predicted to fall within ∼2000 km of a melting ice sheet, and to rise with progressively higher amplitude at greater distances. The physics governing this redistribution is straightforward."(On the West Side of Zero). Mitrovica et al. have followed up on Woodward 1888 with a more robust and polished description of the physics of this phenomenon (The Gravity of Sea Level Change, 2, 3, 4).
This discussion is framed by the declaration: "... it is likely that the sum of all known contributions for this period is smaller than the observed sea level rise ... therefore it is not possible to satisfactorily account for the processes causing sea level rise" (section III.[D.] above, emphasis added).
A. The Scope
In today's post I won't get into a discussion as to why the ghost water phenomenon is not known to Professor Bindoff and his fellow authors, except to say that if you are not looking for something you will most likely not find it.
The discussion will be limited to a look at the Bindoff et al. 2007 arithmetic to try to establish a cognitive link to their unknown which is rendering their SLC arithmetic unsatisfactory.
Note that they are seeing ghost water, but they are only seeing it when it finally arrives at its relocation point where they make their measurements (far from that ghost water's original location).
Note that the clue is hidden in plain sight:
"Sea level change is highly non-uniform spatially, and in some regions, rates are up to several times the global mean rise, while in other regions sea level is falling."(ibid, Section III.[A.] above, emphasis added). If they had asked themselves a question ("where has the water-level, which was once higher around the Greenland Ice Sheet and N. Europe, etc., gone?") they might have connected the dots.
That is, they are missing where it originates, where it is coming from, so it is like finding fingerprints while investigating a case, but not being able to identify who or what made those fingerprints.
That issue is covered by the subject matter "sea level fingerprints," which has been discussed at length here on Dredd Blog (SLC Fingerprints R Us, 2).
Let's begin with "where did the water go?" (The Gravity of Sea Level Change, 2, 3, 4; Weekend Rebel Science Excursion - 54).
The basic essence of ghost water is that when an ice sheet loses ice-mass due to melting or calving, not only does the melt water eventually end up far away, but so does the non-melt, regular coastal ocean water that has been in the ocean but held close to the ice sheet by the ice sheet's gravity (The Battle of the Bulge, The Evolution and Migration of Sea Level Hinge Points).
B. The Ghost Water Arithmetic
Dredd Blog has made general calculations as to the quantity of water ostensibly held by ice sheet gravity.
The current rough calculation of that constant is 27.9% (see The Ghost-Water Constant - 4).
In other words, ghost water equates to an additional ~28% of relocated water in addition to the melt-water quantity (total water relocated = melt-water plus meltwater times 0.279).
Thus, when it is relocated there will be an additional rise in sea level at the final destination location, but there will be a fall in sea level around the ice sheet, its original location.
The entire series, for those who haven't read it, is: The Ghost-Water Constant, 2, 3, 4, 5, 6, 7).
C. The Bindoff 2007 Arithmetic
Let's apply that rough estimate to the Bindoff 2007 estimates depicted in "Table 5.3, p. 419" of the Bindoff 2007 paper (shown at III.[C.] above, click to enlarge).
Their estimates indicate that from 1961-2003 sea level rose "1.1" but the observed is "1.8" which is a difference of "0.7" (0.7 ÷ 1.8 = 39%).
In other words, during that time they say that SLR was underestimated in an amount not too radically different than the Dredd Blog rough ghost water estimates.
The bottom line is that if they do not learn to take the ghost water into consideration, their numbers will be off (Numb: Number & Number).
D. The Bindoff 2007 Temperature
They also estimated:
"The oceans are warming. Over the period 1961 to 2003, global ocean temperature has risen by 0.10°C from the surface to a depth of 700 m."(ibid, Section III.[B.] above, emphasis added). When I took into consideration the total water column (surface to bottom), the temperature change calculation was "Temperature Change: -0.163455" (On Thermal Expansion & Thermal Contraction - 15).
Both estimates are in the ball part it would seem.
Gotta stay in the ball park.
Einstein is purported to have said, among other things, "Everything should be made as simple as possible, but not simpler" (Brainy quotes), which regular readers know is something that I try to do (Weekend Rebel Science Excursion - 49).
In closing, I suppose that the motto of the denialist government now in power in the U.S.eh? is: "If you don't like U.S.eh? sea level, then leave it!"
The next post in this series is here, the previous post in this series is here.
Ode to sharp pencils ...