Monday, September 14, 2015

New Type of SLC Detection Model - 3

Fig. 1 One, two, or three at a time?
I. Introduction

The development of sea level change (SLC) software, which projects future sea level rise (SLR) and/or sea level fall (SLF), must address three fundamental dynamics.

Dynamics that are a function of ice sheet, ice shelf, and ice cap melt (Green Facts, cf. Ice Shelf).

Each of those ice entities takes individual consideration, when software design is contemplated, even though all ice tends to begin to melt when the temperature rises above 32°F or 0°C.

A funny thing is that gravity also "melts away" as those ice entities melt, because they lose mass, which as Newton explained, is the "mother of all gravity" (The Gravity of Sea Level Change).

As shown in Fig. 1, ice caps, ice sheets, and ice shelves are all melting and/or calving, the great bulk of that melt or calving eventually flowing into the sea.

II. The Dynamics Are Not Intuitive, They Are Counter-Intuitive

The most ignored aspect of ice sheet melt and calving is that the gravitational power of the decomposing ice sheet "melts away" too.

That is one important factor that is causing SLC, but which is also melted away from our consciousness by the typical science writer's rush to "simplify" what is going on with the artificial notion of "mean sea level rise."

That SLC is not always SLR at a given latitude and longitude, no, sometimes it is SLF at that latitude and longitude, but at the same time, it is also going to be SLR at some distant latitude and longitude (New Type of SLC Detection Model - 2, On the West Side of Zero).

This phenomenon is a result of the relocation of the sea water that was once captivated by the ice sheet gravity, and held at a higher level near the coast of the land mass that ice sheet rested upon.

In Fig. 1 the dark blue area around Alaska, Greenland, and Antarctica is used to show the area where SLF takes place.

The more ice that melts and flows into the sea, the more the sea level there drops.

That is because the loss of the mass of the ice sheet means the loss of power to pull the sea to the coast like a perpetual high tide.

It is like a storm tide caused by wind forcing high water against the land, but dropping that sea water back to normal levels when the wind dies down.

III. The Dynamics Are Multidimensional

Non-intuitive dynamics are not the only actions taking place at the same time.

A software developer has to also consider the fact that all three actions shown as separate concepts, with separate impacts, on SLC in Fig. 1 are potentially happening at the same time.

Add to that the fact that the ice sheets (Greenland and Antarctica) and ice caps, elsewhere on other land masses, melt and/or calve at different rates.

And, those rates are constantly changing.

For example, Antarctica is gaining on Greenland in terms of ice sheet mass loss by dumping ice and melt water into the seas around them (e.g. Fig. 2).

IV. The Proper Blending of the Dynamics

In the model I already developed, which is under modification to accommodate these
Fig. 2 Antarctica Supersedes Greenland
new dynamics of SLC (i.e. both SLR and SLF) , there is already logic to phase in Antarctica's growing contribution, as well as to diminish both Greenland's and the non-Polar Ice Cap's contributions.

See Fig. 2 where U.S. East Coast SLR (or any other global area of very high relative SLR) is shown at a very fast "two year doubling" acceleration pace; and it also shows where Antarctica (red line) becomes the prime contributor, eventually overtaking the current leading contributor, Greenland (green line).

So, I will simply add front-end logic to properly select those tide gauges, within the geographical grid zone the software model is analyzing at the time, which meet the type of SLC conditions being processed (either SLR or SLF, but not both).

Then, that one (or those several) tide gauge sites will be processed in the context of a changing contribution amount from Greenland, Antarctica, and Non-Polar areas.

Take a look at Fig. 1 again, remembering that those three scenarios are representative of what happens if all the ice at each location melts by itself, the other two having no contribution yet.

In other words, they are imaginary in the sense that the other two are very low (or zero) contributors at that specific time.

Fig. 3  SLF in Zone "aa"
They are not, however, completely imaginary because we know that the bottom scenario (the one which shows blue, meaning SLF, around Alaska) is real.

We know that because the tide gauge at Yakutat, Alaska, near Glacier Bay and shown in Fig. 3, has recorded a 700mm SLF since it became fully operational circa 1940, near a very, very large collection of glaciers that have been busy melting and calving ever since (Proof of Concept).

V. Ever Changing Fingerprint Pattern

The pattern will morph as the Greenland and Antarctica ice sheets sufficiently melt and/or calve and then offset and change the Glacier Bay melt and calving pattern.
Fig. 4  SLR in zone "ak"

The result would appear as a downward SLF track that is not as steep as the Glacier Bay pattern alone.

The same logic applies to Fig. 4 which shows a tide gauge in the same geographical zone ("ak").

It is an SLR latitude and longitude location, so it must not be blurred with any of the SLF zones (to cause that blinding "mean sea level" phenomenon).

And, by the same token Fig. 4 shows that the bottom scenario in Fig. 1 is realistic for both the Yakutat tidal gauge and the San Francisco tidal gauge (blue SLF for Yakutat, cyan or yellow SLR for San Francisco).

VI. Conclusion

Gotta get back to the coding now.

The talking out loud through the keyboard now has to morph into a conversation where I am making software brain circuits.

Circuits to tell the computer how to "think" the problem through.

The next post in this series is here, the previous post in this series is here.

Wooden Ships ...


  1. You're doin' a fine job on this model, Dredd. Remember that there are a LOT of environmental factors collapsing/degrading at this time (and they're all somewhat interrelated). Using the tide gauges is brilliant. It'll indicate data which can then be "interpreted" as to origin(s), beside showing rate over time and level (in real time).


    1. Indeed, as we have previously discussed.

      One wonders why this science is being ignored or overlooked, because the consequences to seaports are practically unimaginable (Peak Sea Level - 2).

  2. Fascinating what's observed at Glacier Bay. Counter-intuitive and how! I keep thinking that another contributor is factoring in; the transfer of land based fresh water from the aquifers (depleting) at a faster rate than can be replenished via natural precip cycles. Many thanks for the 'lesson'! ATB!

  3. Regular readers/commenters, like Tom, know that the credit goes to scientists like Mitrovia, Gomez, Hays, and others. such as Woodward(1888) before them.

    The science is nicknamed "sea change fingerprinting" and is a product of multiple scientific disciplines all looking at the issue from several vantage points.

    Mark, if you want to delve into the science, several of their papers are linked to in a previous post (On the West Side of Zero).

    1. Many thanks Dredd! will do. This a great place to 'delve'!