Beyond Fingerprints: Sea Level DNA

DNA is not alive

I. New Stuff

The notion of sea level "fingerprints" is becoming more and more well-known as time goes on (On the robustness of predictions of sea level fingerprints).

Fingerprints is the word used to indicate that the Greenland Ice Sheet and the Antarctica Ice Sheet cause both sea level fall (SLF) and sea level rise (SLR) across the globe and leave tell-tale indicators when they do.

I think that "DNA" is also a useful and perhaps better term for the tell-tale indicators of sea level change (SLC).

Using "DNA" when referring to the pattern of a geographical location's sea level change (SLC) means its "Defining Natural Attributes" that are the combination of the downward and upward influences over a period of time that is long enough to establish a trend.

A dictionary meaning of "defining" is:

"a defining feature or characteristic is one that is completely typical of something and allows it to be identified"

(Macmillan Dictionary).

A dictionary meaning of "attribute" is:

"a quality or feature of a ... thing, esp. one that is an important part of its nature"

(Cambridge Dictionary).

So, I am presenting that notion of sea level DNA as four components of tell-tale indicators, which are: 1) the distances from a tide gauge location to the ice sheet or glacier field locations, 2) the SLC indicator, 3) the SLR indicator, and 4) the SLF indicator.

These four components indicate which combination of ice sheets and glacier fields caused the sea level to change, hence that location's sea level DNA.

Component 1, data concerning distances is located in the  "Tide Gauge Info: Countries" links, but the other components are linked to separately.

See Section IV & VI below for details about links to the "DNA Graphs" etc. where the components are displayed or discussed.

II. Some Background

All SLC is composed of both SLR and SLF, so when we graph the SLC at a particular location, it has a sawtooth pattern of both upward (SLR) and downward (SLF) lines.

Those lines don't tell us the trend, they are only telling us what happened from time to time, for example what was recorded year by year at a tide gauge location.

The trend is the combination of all of those yearly points (the trend begins at point A and ends at point Z).

Over time, if the sawtooth points get higher and higher the trend is SLR, but if the points get lower and lower the trend is SLF ... even though some of the individual yearly points went up (SLR) and some went down (SLF).

Note that SLF, in terms of sea level DNA, means that the sea level in the particular country went down some, SLR means it went up some, from its level at the previously recorded time.

Examples are: 1) RLR went from 7011 down to 7000 - an SLF of 11 millimeters - for a particular year, 2) RLR went from 7000 up to 7008 - an SLR of 8 millimeters - for a particular year.

This would be indicated by the sawtooth pattern on graph lines of SLC.

III. Now We Know

A few years ago regular reader Tom asked what causes the saw-tooth pattern.

Now we know, Tom, it's in the DNA of the planet's sea level.

The saw-tooth pattern of those DNA strand lines can happen, among other things, because of the winter-summer differences in the ice-sheet locations and the tide gauge locations.

That is, if it is summer at the Greenland ice-sheet, then it is also at the same time winter at the Antarctica ice-sheet (Once Upon A Time In The West - 2).

An ice-sheet loses mass in the summer time by glacial calving or combined ice sheet and glacial melting, but generally not so in the winter time.

Thus, at one time of year the tide gauges at a particular location will be recording one kind of change to a strand of DNA (e.g. SLR), but at the opposite time of year there, the opposite will be taking place (e.g. SLF).

Generally, the degree or intensity of the SLC depends on the volume of melt water and ice loss at the relevant Cryosphere location(s), and the type of SLC (SLR or SLF) depends on the tide gauge's distance from the relevant Cryosphere location(s).

Remember, as I wrote above, that the trend line (not the one-of individual teeth on the sawtooth pattern) is caused by global warming induced ice-mass-loss increases over a long period of time.

IV. The Links

The following table in Section V provides links to countries, graphs of their sea level DNA, and graphs of their SLC.

A. "Tide Gauge Info: Countries"

The "Tide Gauge Info: Countries" column links to an Appendix which names the countries' tide gauge stations, and provides individual links to them.

Additionally, the distances to various Cryosphere locations which impact the sea level of the country is provided, and a general summary of events is provided.

B. "DNA Graphs"

The "DNA Graphs" column links to an Appendix which has a graph detailing each DNA component as it relates to that country.

The red line on the DNA graphs is the Cryosphere locations' SLR impact, the green line is the Cryosphere locations' SLF impact, and in between those two is the SLC line.

C. "SLC Graphs"

Since the SLC (the average of the red and green lines mentioned in section B above) is difficult to see at times, the third column of the table presents a link to the Appendix that graphs the SLC line by itself.

It may be easier for some readers to detect the trend line on this graph than it is on the DNA graphs.

V. How To Read The DNA Graphs

The DNA graphs have a red line (SLR) on top of the three lines in each DNA graph, with a green line (SLF) on the bottom.

These touch the top and bottom of each tooth of the sawtooth pattern.

In between the red and green lines is a black line.

The red line is the SLR line.

The green line is the SLF line.

The black line is the result of the other two, but when the black line equals one of the other two, it can be covered up or have a squiggly or rope-like look.

The red and black line descriptions (legend) indicate the originating Cryosphere locations, which are in parentheses and are noted in abbreviations (e.g. "Pat|Ant").

The abbreviations are defined at the top of each DNA graph.

For example, the "Aland Islands" DNA graph indicates that the green line is the SLF caused annually by "Gre|Sva" (Greenland and Svalbard); which means that Greenland and Svalbard are close enough to the Aland Islands to cause a drag on the red line SLR caused by "Pat|Ant" (Patagonia and Antarctica), which are far enough away to cause SLR.

If this seems counterintuitive (it is), the video at the end of this post is a discussion by Dr. Mitrovica that will inform you of the counterintuitive nature of SLC (cf. On Postglacial Sea Level).

VI. The Link Table

Here is the table of HTML links:

Tide Gauge Info	DNA Graphs	SLC Graphs
Countries: A - C	A - C	A - C
Countries: D - G	D - G	D - G
Countries: H - L	H - L	H - L
Countries: M - O	M - O	M - O
Countries: P - T	P - T	P - T
Countries: U - Y	U - Y	U - Y

VII. Closing Comments

This is my "first pass" on this subject.

In future posts I hope to include percentages that each Cryosphere location has caused (e.g. 50% of SLR, 24% of SLF) instead of the general "location A and location B cause SLR" and "location C and location D cause SLF" type of description.

I also hope to add any other Cryosphere locations that may enhance the hypothesis or presentation.

This is a hypothesis in the development stages.

The next post in this series is here.

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