Peter O’Donnell, who forecasts for IWO, has a dual identity as many might know, in fact a triple identity — he is “M.T. Cranium” on the Boards.ie weather forum, and posts on U.K. and U.S. weather forums under his “real world” name, Roger Smith.
Peter was not a name that Roger invented — he was born with that name, a fact that he only learned after his adoptive parents passed away while he was still a university student. So it was a bit of a bonus for this English-born Canadian to find out that he was actually Irish at birth (at least his mother was).
So he uses the name Peter O’Donnell with pride and thinks about perhaps making a legal name change, but then he has a family and various other reasons (paperwork, mostly) to stay as a Smith. Anyway, one of his interests is global climate and the thorny question of climate change.
Yes, things are changing. The mean temperature at almost every weather station with a long period of record has been on the rise in recent decades, away from the Antarctic at least. And the Canadian arctic is seeing particularly large temperature increases.
In a study recently published on the U.K. weather forum Net-weather, Roger Smith outlines in detail what has recently transpired at two key locations with some long-term climate data, namely Cambridge Bay in the western arctic, and Resolute in the central arctic.
Temperatures were actually falling slightly at these locations from the 1950s into the 1960s and early 1970s. There was a brief spike around 1975, then more relative cold into the early 1980s. Since about 1987, temperatures have been rising steadily. There was a particularly warm period at Cambridge Bay from 1988 to 1991, and at Resolute from 2007 to 2012. This is closely tied in with the much discussed recent ice depletion phenomenon in the arctic, notably north of Siberia and Alaska.
The study found that the more recent warmth was moving from east to west across the Canadian arctic in most of these recent warm summers. A third site, Mould Bay, on the northwest arctic Prince Patrick Island, got just as warm but a week or two after Resolute saw their mini heat wave (at these locations, 18 qualifies as a heat wave).
From 2013 to 2016, the summers reverted back to about where they had been in cooler parts of the 1990s. On a television program, “The Polar Sea” just aired on Canadian television, European sailors trying the Northwest Passage in 2013 were remarking that “global warming didn’t happen this summer” and the ice conditions were difficult for them. They made it through with the assistance of a Canadian government icebreaker when confronted by pack ice in Bellot Strait (about halfway through the Northwest Passage).
The study by Roger Smith also looked at trends in winter temperatures, frost free and snow free intervals in the brief arctic summer, and dates for the maximum snow pack and onset of harsh winter conditions (-20 C or lower). All of these dates have been somewhat consistent with the warming hypothesis although Cambridge Bay has managed to keep most of its snow pack, normally it builds up to 30-50 cms during May then melts in late May and early June. At Resolute, there have been signs of a decrease in snowfall and a shift to more “bimodal” winters where a November or December snow depth peak is followed by a secondary peak in May or early June. The Resolute snow depths in some recent winters have been well below long term normals and sometimes only 10-20 cms instead of the usual 40-60 cms.
One rather unexpected finding was that storminess peaked in the 1960s at Resolute. One storm in November 1965 brought winds that peaked at 158 km/hr — nothing like that has been recorded in more recent decades. Smith has long believed that the arctic circulation responds to the position of the North Magnetic Pole, which actually drifted through the Resolute area in the early part of the study period (in the 1950s) and was located on nearby Bathurst Island to the northwest by 1965. This peak was evident from about 1964 to 1968. There were no reported changes in exact location or exposure of the airport weather station. Meanwhile, some unusually strong winds were reported at Cambridge Bay in the summer of 1971.
The North Magnetic Pole was first located by the Ross expedition in 1839 on the Boothia Peninsula, and since then has slowly drifted north-northwest then later more west-northwest off the Canadian arctic islands altogether by 1990 and it is now estimated to be about 800 miles northwest of Mould Bay or 1500 miles north of Point Barrow, Alaska, on its way towards northeast Siberia.
Before this reliable location was made, changes in the compass directions of Atlantic mariners led researchers to speculate that the NMP was located in Victoria Island during the 17th and early 18th century and drifted southeast from there to where it was discovered by Ross. But that is not a certain finding.
In any case, the study does nothing to answer the big question, why is the climate warming in the arctic? How much of this warming is due to human influences, and how much would be happening if, let’s say, musk oxen and polar bears were the only mammals in the region. There are signs in the climate record that warm phases have come and gone before in the arctic, since the end of the last major glacial period. One such period was around the 11th century and may have lasted three centuries before the first oscillations into the Little Ice Age began. And further back, whale bone records convinced some researchers that there was considerable open water in the eastern arctic around 3,000 B.C. or five thousand years ago.
The current warming seems to indicate a change in air mass frequency more than a warming up of air masses. This is the conclusion drawn when comparing temperatures in each air mass — these have shown much less upward shift than the average temperature. Smith remains skeptical of claims that human modification is causing a change in the circulation patterns. He feels that as-yet-undocumented external drivers such as solar system magnetic field variations are driving changes in the circulation, combined with shifts in the earth’s magnetic field. It seems no coincidence, he says, that temperatures in North America were steadily warming from the mid-19th century to the early 20th century, before the AGW period, and faster than observed in Europe — and he points out that North America was much closer to the northward-drifting NMP in those decades.
If this is a solid lead on climate change cause and effect, the recent very warm intervals in the eastern arctic may become more and more frequent, while temperatures in Alaska and Siberia may respond in the other direction as the closer approach of the NMP deflects milder air masses away. The problem with all this is that the magnetic field is also weakening gradually and could go into some bizarre multi-polarity phase within five hundred years or so.
One study on an internet forum is not going to change the debate much, but for what it’s worth, Smith says that his money is on natural variability rather than human influence, although he assumes that it’s a blend, perhaps on the order of three parts natural, one part human.
If you want to see the data, and the discussion, here’s a link to the Net-weather thread.