Guest post by Ron Crouch
Recently it was reported in the press (here and here) that researchers working at an automated weather station named Isachen on Ellef Ringnes Island, Nunavut, Canada experienced a brief rain shower over the weekend of April 24/25. Now according to David Phillips, the senior climatologist with Environment Canada, this is nothing short of bizarre. Environment Canada statistics show the earliest recorded rainfall in the High Arctic as occurring at Alert on May 21,1988, and the earliest recorded rainfall at Isachen was on June 7, 1975.
So it was put to me on a discussion board that I frequent that over the past 50 to 60 years there was both a lack of stations in the Arctic, and that the population was too sparse to make such wild claims of bizarre rainfall events. Now I'm no Nobel Peace Prize winner, nor do I receive research grants. In fact I'm not employed in the scientific or political arenas. I'm just a reasonably well read average Joe with an average Joe job, but I don't take things at face value either. So I ask as well: "Is the claim of rain in the High Arctic in April being bizarre reasonable or not?"
So I took it upon myself to do a little research of my own. I discovered that between 1840 and 2010 that there have been 168 weather stations in Nunavut. For the 2010 season there are currently 77 stations on line. Perhaps not very many by some standards but certainly enough to give adequate coverage of the region.
For my sampling I chose two Canadian stations and one in Greenland that are all in the same basic geographic area. They are as follows: Eureka on Ellesmere Island, Resolute on Cornwallis Island, and Thule A. B. I chose these three due to the fact that the former two have contiguous records from 1948 while the later has contiguous records from 1952. I further restricted my records search to the month of April.
Now what I discovered was that Eureka has never had so much as a trace of rain over the course of it's records in the month of April. Both Resolute and Thule have a prior history of trace amounts of rainfall in April over the course of their records. After a somewhat boring evening going through the records I found that Resolute had it's first recorded rainfall in April with any measurable amount on April 15, 2010, and subject to further verification stands at 4 mm (upon verification it will be the earliest recorded rainfall in the Canadian High Arctic breaking the old record by more than a month). This is the first and only measurable rainfall that Resolute has ever recorded in April. Now insofar as Thule is concerned their first and only measurable rainfall for April came on April 6, 2008 and racked up a grand total of .25 mm.
So yes the claim that rain in the Canadian High Arctic in April is bizarre -- is
reasonable.
In the off chance that some reader goes off the deep end with a wild claim that this is empirical evidence in support of Global Climate Change, may I remind them that these are one off events and only speak to the oddity of the event itself. However I must agree with the postulations that in a warming world that these types of events may become more commonplace.
Posted by Ron Crouch on Monday, 3 May, 2010
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