This is David Vun Kannon's Typepad Profile.
Join Typepad and start following David Vun Kannon's activity
Join Now!
Already a member? Sign In
David Vun Kannon
Recent Activity
Mostly off topic, but since A-Team mentioned buttressing, the following video is talking about glacier acceleration when the buttress of the floating ice shelf in front of them collapses. From AAAS 2013 meeting. http://membercentral.aaas.org/multimedia/videos/ice-sheets-sea-level-and-other-surprises-benefits-understanding-some-beautiful-pla Recommended for its easy to understand, yet compelling, content.
@Dan Ellis-jones - yes, Ive been watching those huge anomalies in the Antarctic as well. If you click through the chart and then go over to the 'X' for 365 day temps, you'll see that the annual anomaly is about 4C on a base of -30. So, yeah the Antarctic is warmer, but not going to flood the world tomorrow.
Somewhat off topic but based on Hans Gunnstaddar's comment above, I was thinking what would an essentially ice free Arctic look like? Taking 'essentially ice free' to mean 1 million sq km at the end of the melt season, I think that will be (approximately) a half ellipse of ice. The major axis extends from the western tip of Prince Patrick Island to Nordostrundingen, Greenland. The minor axis extends out into the CAB about 300 km. I think this amount of ice could be resistant to summer melting in place, and export, so sea ice minimums might come to rest around this number for a while, perhaps a few years. (Freeze, melt, repeat) After that, I think the main driver for change will be how much heat the Arctic retains over the winter, how many of the regions stop icing over completely. A sea ice maximum of less than 12 MM sq km would really change the weather, IMHO. Scary.
Looking at the regional charts,it seems to me that the largest differences in 'behavior', compared to last year, are in the Beaufort and Kara Seas. But both of these will melt out in time, in any case. In the CAB, there is also a substantial difference in area, but the difference in behavior seemed less obvious. maybe it is just the scaling of the chart. On the GIS, mass balance had been bouncing around the mean until early June, then it dived down to the lower edge of the two sigma (once in 20 year) band. All of the movements of the PAC left a bubble of high pressure over Greenland. 2013 and 2012 are nearly identical so far on the accumulated mass balance chart, but we will have to wait until July to see if 2013 follows 2012 off the cliff.
Not that anyone should really care what Steve Goddard says on his Real Science (sic) blog, but he's taken a run at PIOMAS in a couple of recent eructions. His latest is http://stevengoddard.wordpress.com/2013/06/20/smoking-gun-that-piomas-is-crap/ (Don't click unless you have excess brain cells and no vodka.) I replied (and it is still in moderation over there, naturally): That might be true if all other things were held constant, but of course they aren’t constant. Ice forming from open water has to wait for a lot of energy to go into the phase transition. If the water temperature increased, then there is more heat to dispose of before refreezing begins, and less time throughout the winter for ice to thicken. Also issues with salinity. PIOMAS does have its own ice thickness chart: http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/Bpiomas_plot_daily_heff.2sst.png though Steve’s graph does effectively show the long term, accelerating decline. Now why would that be? Is it natural, cyclical variation, or is it…
Toggle Commented Jun 20, 2013 on PIOMAS June 2013 at Arctic Sea Ice
Neven, perhaps we could have a post about the Greenland ice sheet progress this season? Looking at the steep declines in daily mass balance, it seems that the SMB decline for Greenland has already touched the 2012 level. (Panels 1 & 2 of the chart at http://beta.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ halfway down the page.) However, this strong melting is not spread across the ice sheet in the same way as it was in 2012. As Doomcomessoon pointed out, the 2012 review page shows that much more of the surface was experiencing melt at this point in 2012. That says to me that the melt this year is more intense and localized.
Speaking of falling off a cliff, the Greenland SMB is doing just that. http://beta.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ Halfway down the page, top panel. About to exit the 2 sigma band.
Neven, thank you for adding the Greenland maps to the ASI Graphs page. I'm not sure how complicated your update process is for that page, but it would be very nice to see the monthly updates to the albedo reflectivity instead of the static chart you currently link to. I don't want to sound ungrateful - the page is great and one of my regular morning routines is to visit it.
That last map of the 30-day temperature anomaly might make us breathe easier about Greenland ice, but it doesn't make me feel any better about the Arctic ice! The huge positive anomaly over the East Siberian Sea is like taping a "Melt Me" sign on the back of snowman.
The problems of getting to L1, the instability of staying there, etc. is why I am suggesting a group of larger satellites in orbit around the Earth itself, trying to cool just one part of it, the Arctic in summer.
Here's a satellite based cooling idea. Launch a set of satellites that have elliptical orbits with long times over the poles, sunward of Earth. Unfurl large mirrors to shade the planet. Mirrors on satellites are a lot faster to get in place, incremental and reversible than other solutions. Why make clouds when you can do the same thing above the atmosphere entirely? Bow to BAU, my friends. The only long term solution is population decrease, and we are over a century away from that.
In a Phys.org article linked on the main page of this site is the following - Record ice melts this year and in 2007 have alarmed many scientists, mostly because they thought it would take many more years to reach this state. James Overland, an oceanographer with the National Oceanic and Atmospheric Administration, said forecasts failed to account for the physics of lost solar energy reflection and warming ocean water. "These are really surprises to most scientists," Overland said. "In looking at climate models that are used to look forward, they've tended to say the Arctic may be ice-free by 2040 or 2050. It looks like things are happening a lot faster, and it's because not all of the physics that we're seeing today were well-handled in these climate models. Is it really possible that such basic physics is not part of these models?
Saw this chart in Bob Tisdale's latest over on WUWT: http://bobtisdale.files.wordpress.com/2012/09/12-arc.png Notice the large increase in SST volatility since 2007. Nobody thought it worth mentioning over there.
Toggle Commented Sep 11, 2012 on Minimum open thread at Arctic Sea Ice
Is there a time series of data on AO albedo? I was looking at the supplementary material for the NatGeo article referred to above - Fig S6 has a really large value for seasonal radiative forcing over the Arctic for JJA. First time posting - this site is great!
David Vun Kannon is now following The Typepad Team
Sep 6, 2012