Driftwood On Ice
Tracking the flow of ice in the Arctic is difficult. Reconstructing the extent and flow in times past is even more difficult. An interesting new report has turned to driftwood, embedded in the Arctic pack ice, as a way of deciphering Arctic climate conditions over the last 10,000 years. The researchers found a climate record that is in good agreement with previous histories, including such events as the Medieval Warm Period, the Little Ice Age and the Holocene Thermal Maximum. In fact, they found temperatures during the HTM to be 2° to 4°C higher than today. They also found a complementarity oscillation in sea-ice abundance between East and West that is not correctly simulated by current ice models.
Appearing in the August 5th, 2011, issue of Science, a report entitled “A 10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach” uses driftwood, originating in northern Asia and America, as an indicator of Arctic ice flows in times past. Svend Funder and colleagues analyzed samples of driftwood that accumulated on Greenland’s raised beaches and shores using the wood type and carbon dating. The voyage around the Arctic can take several years and can only occur when wood is incorporated in sea ice from the beginning with land fast ice preventing the wood from landing elsewhere. The driftwood in Greenland is therefore an indicator of multiyear pack ice.
“Our key to the mystery of the extent of sea ice during earlier epochs lies in the driftwood we found along the coast,” said team leader Sven Funder. “One might think that it had floated across sea, but such a journey takes several years, and driftwood would not be able to stay afloat for that long.”
Using this driftwood record, the researchers discovered a couple of interesting anomalies. Unsurprisingly, current ice models do not account for these new finds. The paper's abstract summarizes the results.
We present a sea-ice record from northern Greenland covering the past 10,000 years. Multiyear sea ice reached a minimum between ~8500 and 6000 years ago, when the limit of year-round sea ice at the coast of Greenland was located ~1000 kilometers to the north of its present position. The subsequent increase in multiyear sea ice culminated during the past 2500 years and is linked to an increase in ice export from the western Arctic and higher variability of ice-drift routes. When the ice was at its minimum in northern Greenland, it greatly increased at Ellesmere Island to the west. The lack of uniformity in past sea-ice changes, which is probably related to large-scale atmospheric anomalies such as the Arctic Oscillation, is not well reproduced in models. This needs to be further explored, as it is likely to have an impact on predictions of future sea-ice distribution.
The most direct route for driftwood to take to Greenland is from central Siberia on the Transpolar Drift (TPD), Consisting mainly larch (Larix), the dominant tree species in northern Siberian forests, Asian driftwood takes 2 to 5 years to make the journey. The voyage from North America takes longer and is more precarious. Wood from North American spruce (Picea) forests has to go into the Beaufort Gyre (BG) and swing by Siberia before it can join the TPD. This results in a travel time of 6 to 7 years or more. The changing proportions of larch and spruce indicate changes in the strength of the TPD and BG, both of which are driven by atmospheric circulation from the Arctic Oscillation (AO). The flow of driftwood and ice can be seen in the figure below, taken from the report.
Arctic Ocean ice flows and driftwood sources.
Over the past decade, there have been a number of attempts to rewrite the climate history of the Holocene, the period of interglacial warmth that we are now enjoying. This was done to try and magnify the supposed sudden and abnormal impact that human greenhouse gas emissions are having on world climate. While the authors buy into the global warming dogma, their findings repudiate claims that climate events such as the Medieval Warm Period and the Little Ice Age did not occur. Funder et al. identify four main phases in the development of sea ice in the Arctic Ocean around Ellesmere Island and Greenland:
- Deglaciation of the coastal plain at ~10 thousand years before the present (ky B.P.) was followed by marine transgression. Until ~8.5 ky B.P., there was only sporadic driftwood, and beach ridges occurred only at the southernmost locality.
- The period ~8.5 to 6 ky B.P. marks the Holocene Thermal Maximum (HTM) in this area. Long continuous beach ridges northward along the coast up to 83°N show that this was the southern limit of permanent sea ice, ~1000 km to the north of its present position.
- After 6 ky B.P., there is a sudden rise in driftwood, and beach ridge formation is restricted to the southern areas, showing that periods of open water became shorter from ~5.5 ky B.P. East Greenland’s coast, as well as at Iceland and Svalbard, sea ice emanating from the Arctic Ocean also increased after 7 ky B.P. and especially after ~5 ky B.P.
- At ~2.5 ky B.P., an era of dramatic centennial fluctuations in driftwood abundance and of change of source areas began. The high frequencies are punctuated by woodless periods at 2.5 to 2 ky B.P., 1.7 to 0.9 ky B.P., 0.5 to 0.3 ky B.P., and probably since ~1950.
Further more, the researchers found that the melt levels during the HTM, sometimes called the Holocene Climate Optimum, indicate summer temperatures in north Greenland were 2° to 4°C warmer than now. So much for claims that Earth's climate is hotter now than at any previous time during the Holocene. As for those other disputed climate swings, the authors state: “A larch-dominated peak at ~1100 to 1400 indicates a strong TPD and a weak BG during the Medieval Warm Period, whereas the woodless periods and the increase in spruce after 1400 show that situations with large BG input became increasingly frequent during the Little Ice Age (LIA), as shown also in the western Arctic Ocean.”
“Our studies show that there have been large fluctuations in the amount of summer sea ice during the last 10,000 years,” Funder said in an interview. “During the so-called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50 percent of the summer 2007 coverage, which was absolutely lowest on record.”
Finally, the researchers found that the trends they identified are not present in the computer models. “Despite the similarities at large scale and the long-term trends between model and observations, the complementarity in sea-ice abundance between East (Ellesmere) and West (Greenland), which is seen especially during the HTM, is not simulated in the climate models.” Why are the models not accurate? According to Funder et al., “it is likely that the model deficits are related to a too-weak large-scale AO-type flow response to the orbital forcing during the HTM.”
This report reveals the hypocrisy of global warming booster club scientists. It is not hotter now than at any time in the last 10,000 years, it was hotter by as much as 4°C around 6,000 years ago (back then North Africa was a verdant plain, not a desert). Arctic ice is not melting off to record lows, during the HTM the southern limit of permanent sea ice was ~1000 km to the north of its present position—there was only half as much ice during that relatively warm period.
It should be mentioned that the supposedly endangered polar bear survived this period of low summer ice in fine shape. And according to the physical evidence, all the other notable climate swings recorded by historical authors, such as the Medieval Warm Period and the Little Ice Age, were real. Once again, the climate change alarmists are shown to be either overly excited and ignorant or cynical frauds and liars.
Finally, none of the nuances revealed about ice flow fluctuations are reproduced by the current crop of wonky computer models. If the models were correct they would have predicted the east/west oscillation pattern the author's discovered. As always, doing real science, collecting real empirical data, trumps any number of computer models. Instead of wasting time staring at computer displays, a climate scientist's time would be better spent collecting driftwood on the beach.
Be safe, enjoy the interglacial and stay skeptical.