Dark Snow: Day One
June 20, 2013
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.
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,..
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.
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.