Weekend Rebel Science Excursion - 54

Fig. 1  Stockholm now

Today, I want to question whether or not we have an accurate picture of the sensitivity of the polar ice sheets, ice caps, and glaciers to global warming.

I mean global warming caused by the use of fossil fuels.

Specifically, the questioning comes on the heels of observing some old sea level change (SLC) records (On The Evolution of Sea Level Change).

The use of records made long ago is becoming a popular endeavor for some situations (Citizen-Science, old whaling ship records of Arctic Ice).

Fig. 2 Stockholm "way back then"

I ran across old sea level records kept in Stockholm, Sweden (as ordered by the king) beginning circa 1774.

The graph at Fig. 2 presents those records kept as ordered, and Fig. 1 is tide gauge station records of Stockholm, from the PSMSL. database.

The graph (Fig. 1) is presented in the new Dredd Blog SLC fingerprint format which does the arithmetic for you (SLC Fingerprints R Us - 2).

Other formats of old records, such as photos, are being studied for additional insight (Aerials Records of Greenland circa 1900).

These records suggest that there was much more ice on Greenland way back then, and that it has been melting for a long time.

The indication is that the Industrial Revolution of 1750 began to have an impact on the oceans earlier than previously thought.

The concept many hold today is that thermal expansion was the only game in town that caused SLC way back then.

To the contrary, the old Stockholm SLC records indicate that only about 25 years into the revolution the oceans were being impacted by global warming (induced by a maddening increase in coal burning).

In Sweden's case, the SLC was sea level fall (SLF) caused by the melting of the Greenland Ice Sheet, and it is still ongoing (Proof of Concept - 5).

I may take a look at some of the other old records for more clues (PSMSL - Other Long Records).

The take home from this information is that the Arctic ice sheets had much more volume back then, and they were and are more sensitive to global warming than we have been led to believe (The Evolution of Models - 18).

They still are.

We are making a Titanic mistake if we fail to heed the warnings (Titanic Mistakes Using The W Compass, What Happened to the Iceberg That Sank the Titanic?).

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Glaciers in motion ...

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SLC Fingerprints R Us - 2

Fig. 1 Easier to see SLC fingerprints now

A comment sparked a walk to contemplate a problem, then something dawned on me, so we have some improvement to consider.

In the process of graphing sea level change (SLC) fingerprints, it is better to isolate the changes (the 'C' in SLC), do the math, and then present only the results.

The basic structure is the same: the official historical pattern of the tide gauge station being graphed is still presented in the upper left view, with the data of three contributors-of-influence presented in the other three views (a 4-view graph - Fig. 1).

The individual values of those three (Glaciers, Greenland, and Antarctica) still add up to the "Combined" view values.

What is different is that the PSMSL millimeter values (that tend to be at about 7000 mm RLR (Revised Local Reference) range) have now been adjusted to begin at zero (PSMSL data hovers in the high 6000s to the low 7000s, so you subtract or add to derive the change values).

It is easier to see the dimensions of change over time using the new way, and it requires no subtraction etc. to get the values.

The graph itself has the beginning and end values in the left-most column of vertical numbers.

Fig. 2 SLC over the years

I think that is a better notion of an SLC fingerprint, because the purpose of the fingerprint technique is to inform us about where the change originated.

Now, we also hypothesize how much change was involved at the source (where the ice is melting) in any given year, and also at the terminus, which is the tide gauge station.

This improved format tells us when, and how much, came from each source, and the total of the three sources is summed, then presented in the upper left "Combined" view.

Dr. Mitrovica mentioned, in his video presented on Dredd Blog several times, that even unjustified criticism can spur us to better action, but in this case it was constructive commenting that helped out (On The West Side of Zero).

Regular reader Randy mentioned something here, basically saying "all that a reader has to do is ... ".

I thought "yes, but readers should not have to do that, the model should do that for them."

Bingo, at the same time that the improvement method was conceptualized, the way to do that also seeped through my hard cranium into the gray matter.

So, the fingerprinting R us dynamics have taken a leap forward.

With that improvement in hand, I have regenerated the graphs presented "as a better way to fingerprint sea level change (SLC)," and I am today presenting them once again as a better way to do SLC fingerprinting.

In the first post of this series I graphed Juneau and New York, because they were examples of both sea level fall (SLF) and of sea level rise (SLR).

In Calling All Cars: The Case of the "Missing Six" - 4 some of the "golden twenty-something" tide gauge stations were also graphed "the old way."

So, today you get them "done right" (Fig. 1, Fig. 2), along with the others:

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

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Arctic Report Card From NOAA

Sea level acceleration is in the works folks, because these developments will speed up the Greenland theatre: 

What's new in 2015?

"Maximum sea ice extent on 25 February was 15 days earlier than average and the lowest value on record (1979-present). Minimum ice extent in September was the 4th lowest on record. Sea ice continues to be younger and thinner: in February and March 2015 there was twice as much first-year ice as there was 30 years ago.

Changes in sea ice alone are having profound effects on the marine ecosystem (fishes, walruses, primary production) and sea surface temperatures."

Highlights

"Air temperatures in all seasons between October 2014 and September 2015 exceeded 3°C above average over broad areas of the Arctic, while the annual average air temperature (+1.3°) over land was the highest since 1900. The 2nd lowest June snow cover extent on land continued a decrease that dates back to 1979, while river discharge from the great rivers of Eurasia and North America has increased during that time. Melting occurred over more than 50% of the Greenland Ice Sheet for the first time since the exceptional melting of 2012, and glaciers terminating in the ocean showed an increase in ice velocity and decrease in area."

"Walruses are negatively affected by loss of sea ice habitat but positively affected by reduced hunting pressure, while sea ice loss and rising temperatures in the Barents Sea are causing a poleward shift in fish communities. Widespread positive sea surface temperature and primary production anomalies occurred throughout the Arctic Ocean and adjacent seas as sea ice retreated in summer 2015."

(NOAA).

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Arctic Report Card 2015:

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Calling All Cars: The Case of the "Missing Six" - 4

Fig. 1 A pattern of evidence

I think that the case of the missing six is now moot.

So, you and I can stop searching for the holy grail now.

That is because there is a more robust way to discern the fingerprint (FP) of sources of influences in tide gauge station records.

That was pointed out in the basic hypothesis set forth in yesterday's Dredd Blog post (SLC Fingerprints R Us).

The fundamental essence of the case is:

1) a land based ice source (ice sheet or glacier) melts or calves to release some part of itself from the land into the ocean;

2) which increases the ocean's volume;

3) and diminishes that ice source's volume, mass, and gravitational power;

4a) the melt water / ice source's loss of gravitational power releases its grasp on sea water around it; 4b) the released melt water warms, the calved ice melts and then that melt water also warms;

5) the Earth's gravity, axial location, rotation, and ocean currents relocate all of the water released into the ocean realm;

6) tide gauge stations at or near the source, the terminus, and even along the way, will record that relocation as sea level change (SLC);

7) those tide gauge station records of SLC therefore contain evidence which can be used to determine the source or sources of that SLC.

The number of tide gauge stations around the world were considered then condensed into the "golden twenty some odd" for specialized reasons (Fig. 1).

It is possible that the following (still good) stations (still active) are some of those "golden twenty some odd" stations:

Newlyn (202)
Brest (1)
Marseille (61)
Trieste (154)
Honolulu (155)
San Francisco (10)
Balboa (163)
Key West (188)
Aberdeen I (361)
North Shields (95)
Charleston I (234)
Hampton Roads (299)
Baltimore (148)
Atlantic City (180)
New York (12)
Eastport (332)

(Calling All Cars: The Case of the "Missing Six" - 3). Fortunately, there is an alternate way to determine the information, the FP (maybe even a better way? ... you decide).

So, today I will use the new Dredd Blog format for some of those "golden twenty something" stations to illustrate the point (Fig. 2).

Fig. 2  Read this first.

There are four graph sections to each full graph, the first section (upper left) is the combined totals (it is also the official PSMSL tide gauge station record for the station depicted).

The other three views or sections concern the contribution (in millimeters) that the ice sheets of "Antarctica" and "Greenland" make, as well as the contribution that glacial fields and ice caps on land make ("Glaciers").

The years involved in each view are displayed along the bottom of each graph.

Any one point in the three non-combined views adds up to that X-Y location's value in the combined view (top left graph):

You can see that displaying and quantifying the actual amounts for each SLC source is a robust way to deliver the information eh?

Each individual tide gauge station, not just a few, has the "DNA" to reveal the information using some simple algebra.

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

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Got Heart?

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SLC Fingerprints R Us

Fig. 1 Juneau, AK

I am moving along with the sea level change (SLC) "fingerprint" (FP) algorithms in the Dredd Blog software model.

Specifically, it may be the first model to FP individual PSMSL stations en masse, since it goes through all 487 PSMSL "good" tide gauge stations in the SQL database I built, and while doing so it FP's them ("good" stations are those that have been active for at least 30 years, and are still active).

Not only that, part of the FP mode gives some detail as to how much each ice source (Greenland, Antarctica, and non-ice-sheet glaciers) has/have contributed to sea level rise (SLR) and sea level fall (SLF) at each individual station.

I have provided two beta version graphs to illustrate the way it is working now (but it is going to work more robustly when it gets out of beta).

Fig. 2  New York, NY

 I chose a station that experiences SLF (Juneau, Fig. 1), and another that experiences SLR (NY, Fig. 2).

The SQL database contains records for the distances from each station to the various ice sources.

The SQL database also contains a percentage representing how much each ice source contributes to influencing each station's current sea level.

I use proximity to sources-of-influence, as the first analysis, to rough-frame the initial picture.

Fig. 3 Juneau sans fingerprint data

The vertical numerical-column on the left side of each of the four depictions in each graph (Fig. 1, Fig. 2) indicates the strength of influence (the "combined" is the sum of the other three - each value point of the three add up to the value point in the Combined view).

The horizontal numbers at the bottom of each of the four sections in each graph indicates the years involved in that SLC FP section.

The span of years and the pattern in each of the four sections of each of the two graphs has the same "look and feel", i.e., only the intensity of each influence source varies (IOW "same DNA").

Fig. 4  New York sans fingerprint data

For example, in Fig. 1 you can seen that the left column numbers indicate that glaciers (Glacier Bay in this case) are the most influential players in this SLF part of the world, but in Fig. 2,  you see Greenland being the most influential.

The essence of the SLC FP view is to identify the players that are influencing the SLC.

If the influence changes these numbers will likewise change, and thereby tell us in turn which ice sheet changed (Fig. 3 and Fig. 4 show the same stations without the FP data).

Super FP work involves processing all good individual tide gauge stations, and telling how much each of those SLC sources is contributing to that one location's FP.

As of now, as you can see by the graphs, I am into the preliminary algebra, and so forth, for doing that.

At the moment I have not plugged in the two modules that will supplement the FP mode and fine tune it.

More on that later.

But you get the picture:

It is important to consider the separate fingerprints of RSL from the major sources to investigate their individual gravitationally-consistent “fingerprints”, but for present-day and future trends in sea level, it is the combined signal that is important. To first order, this can be approximated as the sum of the individual sources.

(Cryosphere, cf. Oceanography). One cannot have a "combined" without having the individual parts to combine into one.

Stay tuned.

The next post in this series is here.

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