This is David Appell's Typepad Profile.
Join Typepad and start following David Appell's activity
Join Now!
Already a member? Sign In
David Appell
Recent Activity
Your posts have gotten very formulaic. Your heart isn't in them anymore. Not a big deal -- it happens.
Toggle Commented Jul 7, 2017 on PIOMAS July 2017 at Arctic Sea Ice
"...The ocean contains a lot more energy than 1 W/m2" A W/m2 is a unit of energy exchange, not energy itself.
Ok, I see, Neven is referring to area..... My understanding is that sea ice researchers consider extent to be more fundamental than area, due to melt ponds.
Toggle Commented Feb 10, 2016 on Global sea ice area record minimum at Arctic Sea Ice
Alex: I'm referring to NSIDC data on extent, not area.
Toggle Commented Feb 10, 2016 on Global sea ice area record minimum at Arctic Sea Ice
This isn't true with NSIDC data, though -- there the annual global SIE is, so far, only 3rd-lowest. And it doesn't look to be going much lower....
I am having trouble seeing how the first GIF shows a calving. What are the telltale signs?
Toggle Commented Aug 16, 2015 on Jakobshavn record retreat at Arctic Sea Ice
I remember why I avoid this blog -- close mindedness. Thanks for the affirmation.
The Arctic SIE mean of CMIP5 models is about 2 Mkm2 for the year 2100. The -1 sigma line hits zero about 2060. (Current Arctic SIE is more in line with the -1 sigma value than the mean.) A couple of models show SIE=0 as early as 2025. Julienne Stroeve et al reviewed Arctic SIE trends and CMIP5 & CMIP3 models last year in: "Trends in Arctic sea ice extent from CMIP5, CMIP3 and observations," Julienne C. Stroeve1 et al, Geophysical Research Letters Volume 39, Issue 16, 28 August 2012 From the paper: "Several CMIP5 models (CanESM2, GISS E2-R, GFDL-CM3, NCAR CESM, MIROC-ESM and ESMCHEM) show essentially ice-free conditions by 2050, with the CanESM2 model having an ensemble member reaching nearly ice-free conditions as early as 2016 (0.54 x 10^6 km2). By contrast, despite the more aggressive emission scenario (SRESA1B) driving the CMIP3 models, an overall more extensive sea ice cover is retained, with the minus 1 standard deviation reaching nearly ice-free conditions in 2075." They define "ice-free" as less than 1 Mkm2, and use the RCP4.5 scenario.
Toggle Commented Jan 10, 2014 on PIOMAS January 2014 at Arctic Sea Ice
2. Having an oddball year that we cant make sense of immediately is a great scientific opportunity. Yes. But between sea ice and the 15-yr pause in surface warming, we can expect even more "global warming is over" from the denier-types.
To check Zhang et al (2010) that I referenced above: I took the PIOMAS daily sea ice volume and calculated its 1978-2009 summer mean, with summer taken as June 21 - Sept 21. The average was 19.35 Kkm3. The results for subsequent years, as a percentage of this mean value, are: 2010 39% 2011 36% 2012 33% which are already in the range of "10-37% as early as 2025" their model predicts, though faster than the model, assuming I defined "summer" as they did and I haven't made any errors. Of course, it's also possible the model is wrong, for either future projections, past volumes, or both. Zhang et al (2010) write that the future rate of melting it expected to slow down: "The projected annual mean ice volumes decrease substantially during 2010–2025.... They decrease at lower rates in later years, particularly over 2030–2050 (Table 2) even as SAT [surface air temperature] continues to increase. One reason is that, although ice melt mainly in summer continues to increase with increasing SAT (Figure 3c), thermodynamic ice growth mainly in winter increases too (Figure 3b) because thinner ice has a higher growth rate [Bitz and Roe, 2004]. In fact, the linear increasing trends of annual mean ice growth over 2010–2050, like those of annual mean ice melt, are comparable to the trends over 1978–2009 (Table 2). Another reason is that ice export from the Arctic decreases in the future, just as in 1978–2009 (Figure 3a and Table 2), because of reduced ice thickness (Figure 2) [Holland et al., 2010]. As a result, the linear decreasing trends of the net ice change (ice growth minus ice melt and ice export) in the Arctic are small, especially with A2 and B2 (Table 2), leading to much lower trends in decreasing ice volume during particularly 2030–2050 (Table 2)."
Paul Beckwith wrote: Notice that Walt Meier does not discuss the PIOMAS sea ice volume exponential decline that has been basically substantiated by the Cryosat measurements. Even the PIOMAS group does not predict an summer ice-free Arctic until the mid-2040: "Arctic sea ice response to atmospheric forcings with varying levels of anthropogenic warming and climate variability," Jinlun Zhang, Michael Steele, Axel Schweiger Geophysical Research Letters Volume 37, Issue 20, October 2010
If you want to take out a loan, pay for the interest yourself. The government should not be assisting you -- that's basic libertarianism.
Toggle Commented Apr 16, 2013 on Happy Tax Day! at MaxRedline
The data farm started under Bush Jr.
In 1992, the top tenth of the population controlled 20 times the wealth controlled by the bottom half. By 2010, it was 65 times. .
Toggle Commented Apr 16, 2013 on Today They Celebrate A Great Victory at MaxRedline
Max, there are SERIOUS problems with commenting here. Typepad doesn't recognize Twitter, or Facebook.... it's a big hassle just to try and comment. Please get a decent system.
Toggle Commented Apr 16, 2013 on Today They Celebrate A Great Victory at MaxRedline
Tax Burden for Most Americans Is Lower Than in the 1980s NY Times, 11/30/12 .
Toggle Commented Apr 16, 2013 on Today They Celebrate A Great Victory at MaxRedline
David Appell is now following The Typepad Team
Jul 6, 2011