This quarter, Gerard Roe suggested something a bit different for a reading seminar, inspired in part by visiting professor Jamie Shulmeister and in part by paleo-glacier puzzles. The topic is ‘The Natural Variability of Glaciers’. Here is Gerard’s introduction:
The widespread and ongoing retreat of glaciers is a powerful totem of anthropogenic climate change. Moreover, reconstructions of past glacier fluctuations feature heavily in our narrative of past change. Glacier history is thus one of the key links between past and future climate.
While the current warming is indisputable, the situation in the centuries and millennia prior to the instrumental record is more opaque and fragmentary. As is true for all climate proxies, the interpretation of glacier records is a classic exercise in signal-to-noise detection. What aspects truly reflect climate change and require a change in climate forcing to explain, and what are simply to be expected in the normal operation of a noisy system?
The start of the quarter Gerard will give a few lectures, and then we will dive into the literature:
Week 1: Statistics; review of glacier mass-balance records
Medwedeff, W.G. and G.H. Roe. Trends and variability in the global dataset of glacier mass balance. Submitted.
Week 2: Glacier response to climate; basic models, trend detection, glacier-length variance
Roe., G.H., and M.B. Baker, 2014: Glacier response to climate perturbations: an accurate linear geometric model. J. Glaciology, 60, 670-684.
Week 3: Improved models; excursions statistics
Reichert, B., L. Bengtsson, and J. Oerlemans, 2002: Recent glacier retreat exceeds internal variability, Journal of Climate, 3069-
Roe., G.H., and M.B. Baker, 2015: The response of glaciers to climatic persistence. In press.
Burke, E.E., and G.H. Roe, 2014: The persistence of memory in the climatic forcing of glaciers, Climate Dynamics, DOI: 10.1007/s00382-013-1758-0.
Week 4: Continued lectures from Gerard; Michelle gives brief introduction to numerical glacier models following this great set of papers:
Adhikari and Marshall (2011), Improvements to shear-deformational models of glacier dynamics through a longitudinal stress factor
Adhikari and Marshall (2012a), Modelling dynamics of valley glaciers
Adhikari and Marshall (2012b), Parameterization of lateral drag in flowline models of glacier dynamics
Adhikari and Marshall (2013), Influence of high-order mechanics on simulation of glacier response to climate change: insights from Haig Glacier, Canadian Rocky Mountains
Week 5: Lecture from Jamie on Dating Holocene moraines in New Zealand
Week 6: Claims and counter-claims of global climate signals in Holocene glacier records
Schaeffer et al., 2009: High-frequency Holocene glacier fluctuations in New Zealand differ from the Northern signature, Science 324, 622-625.
Winkler, S. and J.A. Mathews, 2010: Holocene glacier chronologies: Are ‘high-resolution’ global and inter-hemispheric comparisons possible?
For the rest of the quarter we follow references from set of papers in 2009 special issue of Quaternary Science Reviews (28), and more recent publications. The review articles are a great place to start. How many of documented historical glacier fluctuations were likely due to a climate change?
Week 7: Go through glacier records — Antarctica; European Alps
Week 8: Go through glacier records — Greenland, Arctic, Iceland, USA
Week 9: Go through glacier records — Scandinavia; New Zealand; Central Asia
Week 10: Go through glacier records — South America
(The feature photo is taken on the lateral moraine of Blue Glacier, Olympic Mountains, Washington)