Volume 15, Number 52: 26 December 2012
Bjork et al. (2012) report that "using state-of-the-art photographic and aircraft technology, the seventh Thule Expedition (Gabel-Jorgensen, 1935, 1940) conducted a systematic survey of the southeast coast of Greenland in 1932-1933." But after the initial use of the survey's images, they indicate they were "archived in a citadel outside Copenhagen, and knowledge of their location forgotten."
The nine modern-day researchers, however, somehow rediscovered the early images; and together with air photos obtained by the U.S. military in the World War II era, they used them to analyze the frontal behavior of fully 132 glaciers along the more than 600 km of the southeast Greenland coastline (between 61.5 and 66.5°N latitude), along with a little help from other aerial photos taken in 1943 and 1981-1985, terrestrial photos from 1933, and satellite images from 1965, 1972, 2000 and 2010.
So what did they learn?
The team of Danish and U.S. scientists report that two recessional events stand out, one that occurred during the 1930s (1933-1943) and another that occurred during the 2000s (2000-2010); and they state that the second of these retreats was "matched in its vigor" during the "period of warming in the 1930s with comparable increases in air temperature." In fact, they say that "many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s," but they indicate that "marine-terminating glaciers retreated more rapidly during the recent warming."
With respect to the net future status of all of the studied glaciers, however, Bjork et al. write that "the recent high rate of retreat may come to a slowdown when retreating marine-terminating glaciers reach their grounding line and become less sensitive to the influence of ocean temperature (Howat et al., 2008; Moon and Joughin, 2008), or through positive or negative feedback mechanisms relating to the cold East Greenland Coastal Current (Murray et al., 2010)."
For the time being, therefore, we will simply have to adopt a "wait and see" perspective on what the future may hold for the glaciers of southeast Greenland. They may well hang around a whole lot longer that what many climate alarmists have predicted.
Sherwood, Keith and Craig Idso
Bjork, A.A., Kjaer, K.H., Korsgaard, N.J., Khan, S.A., Kjeldsen, K.K., Andresen, C.S., Box, J.E., Larsen, N.K. and Funder, S. 2012. An aerial view of 80 years of climate-related glacier fluctuations in southeast Greenland. Nature Geoscience: 10.1038//NGEO1481.
Gabel-Jorgensen, C.A.A. 1935. Dr. Knud Rasmussen's contribution to the exploration of the south-east coast of Greenland, 1931-1933. Geography Journal 86: 32-49.
Gabel-Jorgensen, C.A.A. 1940. Report on the Expedition - 6. Og7. Thule-Expedition til Sydostgronland 1931-1933. Meddelelser om Gronland 106.
Howat, I.M., Joughin, I., Fahnestock, M., Smith, B.E. and Scambos, T.A. 2008. Synchronous retreat and acceleration of southeast Greenland outlet glaciers 2000-06: Ice dynamics and coupling to climate. Journal of Glaciology 54: 646-660.
Moon, T. and Joughin, I. 2008. Changes in ice front position on Greenland's outlet glaciers from 1992 to 2007. Journal of Geophysical Research 113: 10.1029/2007JF000927.
Murray, T., Scharrer, K., James, T.D., Dye, S.R., Hanna, E., Booth, A.D., Selmes, N., Luckman, A., Hughes, A.L.C., Cook, S. and Huybrechts, P. 2010. Ocean regulation hypothesis for glacier dynamics in southeast Greenland and implications for ice sheet mass changes. Journal of Geophysical Research 115: 10.1029/2009JF001522.