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Wednesday, July 31, 2019

The Less Well Known Areas of Sea Level Change

Fig. 1 Just for grins
I. Background

Dr. Mouginot and Dr. Rignot pointed out that concentrating on too few examples to the exclusion of others can lead to mistakes or over emphasis ("This result illustrates the risk of summarizing the ice sheet loss on the basis of the fate of a few glaciers." - see their recent paper  at p. 9242).

Their take-home suggestion and practice ends up being consideration of the entire ice sheet, or at least all of a particular type of glacier, such as tidewater glaciers.

I think that the same reasoning goes for "sea level fingerprints" or "sea level DNA" as I like to call it, because we can also make mistakes when considering the competing impacts from different areas of the Cryosphere on the whole of the sea level change picture (Bamber et al.).
Fig. 2 NASA detective work sees ghost water

II. Overviews

The graphic at Fig. 1 shows the segmented view that results when multiple sources are detailed.

The graphic at Fig. 2 shows a different result when most or all of the contributing factors are considered as one dynamic.

Fig. 3 WOD Zones in high SLF areas

I modified that Fig. 2 graphic by superimposing WOD Zone numbers onto it in the high sea level rise areas Rignot et al. set forth (Fig. 3).

Not all of those zones have tide gauge stations (more below).

I also made changes to the shoreline of East Antarctica (Fig. 3) where sea level fall is taking place and will continue to take place according to another Rignot/Mouginot paper indicating that ice mass loss is accelerating there in significant and robust numbers of gigatons.

III. Graphs Of The High SLR Zones

Even though many of those high water zones are out in the deep ocean where there is no shoreline upon which to place tide gauge stations, nevertheless, there are a lot of tide gauge stations to use (56 currently).

So, I was able to generate graphs that show in fact that considerable sea level rise is taking place as expected.

The graphs are displayed in Appendix One and Appendix Two.

Appendix One contains the three-line DNA graphs while Appendix Two has the same lines with the added fill-in so as to hint at the scope of the sea level changes there.

There is one graph in each appendix that includes all of the zones with tide gauge stations, additionally there are multiple "layer graphs" which only contain the tide gauge stations included in one latitude layer (layer 3 through layer 14).

In a future post of this new series I hope to calculate sea level rise at zones that do not have tide gauge stations.

That entails using arc-of-the-earth's surface trigonometry.>

In other words, we can calculate the height (sagitta) at the center of the arc using two tide gauge stations at two different longitudes at each end of the arc, but at the same latitude (hopefully).

It will also require satellite records enhancement, if it can be done at all.

Then we can also make an attempt to calculate the gigatons of ice mass loss using the maximum sea level height factors derived with the trigonometry / satellite calculations (Ice Sheet Melt According To Tide Gauge Stations - 2).

It will probably take until midnight to complete it.





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