A NOTE ON THE TEMPERATURE TREND, I81 5-1963, AS REVEALED BY THE CLOSING DATES OF NAVIGATION ON LAKE CHAMPLAIN
It has been recognized that a warming trend in the North Atlantic Basin started near the end of the 19th century. As a contribution to the study of this climatic trend we decided to analyze the ‘iclosing dates ” [l] for Lake Champlain (fig. I), after the methods of H. Arakiiwa [2], A. V. Havens [3],...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.3200 http://docs.lib.noaa.gov/rescue/mwr/092/mwr-092-06-0330.pdf |
| Summary: | It has been recognized that a warming trend in the North Atlantic Basin started near the end of the 19th century. As a contribution to the study of this climatic trend we decided to analyze the ‘iclosing dates ” [l] for Lake Champlain (fig. I), after the methods of H. Arakiiwa [2], A. V. Havens [3], and 1’. H. Kutschenreuter [4]. We felt that the use of “closing dates, ” rather than convcntional temperature data, would better shorn the ~iiacroclimatic changes and would minimize the chance of error brought about by changes of exposure, instrumentation, and observationd technique. Also, the date on wliich a body of water the size of Lnke Chnmplain freezes over between Burlington, Vt., and Port Douglas, N.Y., is a function of many, rather thnn just a few days of subfreezing temperatures, and is, thercfore, a fairly good indicator of the sererity of the winter up to that the. Closing dates for Burlington to Port Douglas navigation:ire given in cliroiiologicd order in [I] for tlie period beginning with the winter of 1815-16 up to and including the winter of 1953-54. The data for the seasons 1954-55 through 1962-63 (table 1) are taken from the records of the Weather Bureau Airport Station, Burlington, Vt. For the full period, 14s years, there are two winters missing (1S29-30 and 1S30-31), and 13 “open ” winters (tiLble 2), in which the Lake did not freeze 01-er between the two ports. Our first step was to estimate the mean closing drLte (s) and standard deviation (8) for the full period, lcss of course the two missing winters and the 13 open winters. We found x’=33.45 (approximntely February a), with:in 8=14.05. We then performed a “runs test ” [5] on the entire period, the result of dich indicated a trend toward Mer closing dates, but did not give conclusive evidence of tlie trend. r |
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