Dark Snow: Day One

June 20, 2013

dailymelt619

Detroit Metro Airport, June 20:

It’s happening. I’ll be in transit over the next 20 hours or so.

We are still in fundraising mode btw.  Flight schedule is still in flux, and every donation means more ice time for the scientific team.

supportdarksnow

First stop, Copenhagen, where Dr. Jason Box now holds a position at the Geological Survey of Denmark and Greenland. We’ll be flying from there to Greenland in a few days. Meanwhile,..

Meltfactor.org (Dr. Jason Box’s blog)

Our not so old science of glaciology, beginning in earnest in the late 1950s, can now begin unifying surface and ice dynamics processes at the ice sheet scale. In stark contrast to the messaging that the recent Nick et al modeling study produced, we may expect plenty more sea level contribution from Greenland than current models predict. The misreporting of otherwise good science refers to ice flow to the sea as “melt”. Ice deformational flow is a distinct process from melt. Yet, melt and ice deformational flow are in fact intertwined processes. Self-reinforcing amplifying feedbacks outnumbering damping feedbacks by a large margin (Cuffey and Patterson, 2010, chapter 14) ensure that given a climate warming perturbation, a.k.a. the Hockey Stick, we’ll see a stronger reponse of ice to climate than is currently encoded by models. More on that later.

greenlandmeltext619

Because the peak statistical sensitivity between meltwater runoff and ice flow discharge emerges at the decade scale (11-13 years), it seems that the ice softening due to more meltwater in-flow to the ice sheet, the Phillips Effect, if you will, is a central physical process behind a link between runoff and ice flow dynamics (Phillips et al. 2010; 2013).

Yet, on shorter time scales and resulting from a rising trend of surface melting, also to be considered is the effect of meltwater ejection at the underwater front of marine-terminating glaciers. The effect is to force a heat exchange between the glacier front and relatively warm sea water with the ice  (Motyka et al. 2003), melting it. This is, if you will, the Motyka Effect. Underwater melting undercuts the glacier front, promoting ice berg calving and thus providing a direct and immediate link between surface runoff and ice flow. Calving reduces flow resistance, causing ice flow acceleration.

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7 Responses to “Dark Snow: Day One”

  1. mspelto Says:

    Increased runoff would also increase fjord circulation which can increase basal melting for floating portions of a glacier. The two effects you note above were identified much earlier by others, so should not be attributed to those noted.

  2. rayduray Says:

    Seattle PI headline:

    “Why NASA’s latest photo of Alaska is freaking people out”

    http://www.seattlepi.com/national/article/Why-NASA-s-latest-photo-of-Alaska-is-freaking-4612565.php#page-2

  3. astrostevo Says:

    Excellent news – hope you have a great , productive and fun trip.

  4. rayduray Says:

    Transcript of the President’s Climate Change Speech as delivered on June 25.

    http://www.bloomberg.com/news/2013-06-25/-we-need-to-act-transcript-of-obama-s-climate-change-speech.html

    I have commented on the section pertaining to the Keystone XL pipeline here:

    http://www.occupybendor.org/news.php?2020

    • junkdrawer88 Says:

      Sadly, I think you’re right.

      1.) He signaled that he’s going with the State Department over EPA. And State has been saying the pipeline reduces GHGs. How? IF (big dubious IF) you assume that the oil will make it to market one way or another, then a pipeline beats, say, trucking it or shipping it.

      2.) He said nothing about the potential for tar spills.


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