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10% of sea level rise is due to land rising too. Got that?

Posted By Joanne Nova On May 19, 2011 @ 12:51 am In Global Warming | Comments Disabled

Just in case you missed it, there has been yet another example of data manipulation in the endless round of adjustments that bring reality closer to the models. Thanks to James Taylor in Climate Change Weekly for drawing our attention to it.

Sea levels are one of the top five most critical measurements to tell us about the planet’s “heat”. Remember, they say “it’s worse than we thought” and that sea level rise is accelerating. Yet the measurements by the best equipment available — satellites — tell of a steady linear rise of just 3mm year after year, except for lately, when it’s been lower. (What kind of scientist can’t predict where a straight line is headed?)

Sea level is hard to measure — the sea is not flat — the ground also moves, but satellites measure the world’s oceans every ten days to an accuracy of several millimeters, and what’s more, they measure it compared to the center of the Earth (see below). NASA says so. So it is hard to explain why, after delaying the latest (shrinking) results for a couple of months past the usual posting date, they now announce that they’ve added “a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA)”.

The trend since 2006 has been flatter than the previous 12 years.

According to the University of Colorado the GIA is apparently needed to compensate for all the glaciers which have melted — taking the weight of the ice off the continents, and letting that land rise up.

Silly me, I thought the point of worrying about sea level rise was the concern about sea-rising compared to the beaches, what’s the point of building a levee to keep out the water if the beaches are rising as well?

Hidden in the adjustment is the news that (they say) the world’s land masses are rising 10% as fast as the oceans. Who knew? The continents are getting 0.3mm higher each year!

NASA Ocean Surface Topography describes how accurate satellites are:

From its vantage point 1336 kilometers (830 miles) above the Earth, the US/European Jason-1 and OSTM/Jason-2 ocean altimeter satellites measure the height of the ocean surface directly underneath the satellite with an accuracy of 4-5 centimeters (better than 2 inches). Traveling in excess of 7 kilometers (4 miles) every second as they trace out an orbit, the spacecraft cover the global oceans every 10 days (the “repeat period” of the satellite orbit).

To take a measurement, the onboard altimeter bounces these pulses off the ocean surface and measures the time it takes the pulses to return to the spacecraft. This measurement, multiplied by the speed of light, gives the range from the satellite to the ocean surface. After correction for atmospheric and instrumental effects, the range measurements are accurate to less than 3 centimeters. The range measurements are subtracted from POD-derived estimates of the satellite orbital height, resulting in ocean height measurements that are good to 3 centimeters (just over 1 inch) relative to the center of the Earth.

This accuracy figure pertains to a few-kilometer spot on the ocean surface directly beneath the satellite. By averaging the few-hundred thousand measurements collected by the satellite in the time it takes to cover the global oceans (10 days), global mean sea level can be determined with a precision of several millimeters.

If authorities inform us the sea level rise is accelerating, how would we know?

We could all go down to our local beach and look, but we could be told by the data masters that the rises are happening “somewhere else”. Only people with access to the raw data can really know what is going on.

To prevent servitude due to statistical manipulation all we need, see, is to put up our own satellites and collect a second set of independent data right? I’ll pass around the hat…

Like so many adjustments the pattern is undeniable. It may be unconscious projection, but the researchers leave no stone unturned in the quest to find the “right” answer. Any individual adjustment can be explained in apparently reasonable-sounding terms (at least until you think about it). The pattern of non-random changes that nearly always favors the scare campaign, cannot.

ADDENDUM

When do the adjustments start?

What’s not clear from the release by UC is when the GIA adjustment begins. Mike Jonas, a diligent Watts Up reader produced this quick (unverified) graph of the difference between the old UC data and the new data. The adjustments for the whole period (1994 – 2011) non-randomly average above zero, but the larger and more consistent corrections seem to start around 2002.

Click to enlarge the image

The big unknown

From an alarmist’s point of view, the changes must be hard to explain too and you wonder if they ever pause and ponder. Somehow, someway, the thermometers, hot air balloons, Argo buoys, and satellites are all giving answers that need adjustment in the same direction. [Cue spooky music]. The instruments are systematically and repeatedly underestimating global temperatures, sea levels, ocean heat content. How could that be? It’s like there is an equipment-conspiracy…

UPDATE:

Ecotretas has done a different before and after graph of the sea level figures — specifically, on the rate of the yearly rise.  Which ever way you look at it, the trend is falling.

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