Wednesday, April 26, 2017

New Study: Sea level Rise is Accelerating

Sea level rise is up 25% since the 1990s, according to a new paper in GRL, mostly due to melting in Greenland. From an AGU blog:

From the paper's abstract:
The new GMSL [Global Mean Sea Level] rate over January 1993 to December 2015 is now close to 3.0 mm/yr. An important increase of the GMSL rate, of 0.8 mm/yr, is found during the second half of the altimetry era (2004–2015) compared to the 1993–2004 time span, mostly due to Greenland mass loss increase and also to slight increase of all other components of the budget.
Here is their final result, after all bias corrections:

which clearly is increasing faster than linear. The paper doesn't actually give a value for the acceleration -- it obviously depends on the times chosen -- but I'll try to estimate it. 

They write, "The EM [Ensemble Mean] GMSL rate is significantly lower during the first period compared to the second one (2.7 ± 0.2 mm/yr versus 3.5 ± 0.15 mm/yr)...." 

The two observation periods are Jan1993-Dec2004 and Jan2004-Dec2015 (yes, there's a slight overlap; I don't yet know why). Their midpoints differ by 11 years, so the acceleration is about

where SLR is Sea Level Rise. This is about what I get from fitting the Aviso-only data to a quadratic, as I did here, which now comes to 0.06 mm/yr2.

Saturday, April 22, 2017

Best #MarchforScience Posters and Signs

I'll keep this post pinned at the top as I find more and add them. Suggestions welcome.

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