Guest commentary by Vicky Slonosky
One of the lesser-known branches of climatology is historical climatology, the study of past climates from historical records of instrumental observations and weather descriptions, with “historical” often loosely taken to mean “pre-government-organized-meteorological or weather service” observations. In the last ten years or so, with the development of digital imaging, increased storage and processing capabilities of computers, it’s become possible to think about analyzing these past records on a daily basis. Snowstorms, hurricanes, cold snaps or heat waves all happen on daily scales, and daily information over the past 200 years or more let us learn more about them. All over the world, efforts (many unfunded) are going on to try to find and preserve these historical data from personal weather diaries, scientific observatories and naval records. This is often described as “data archeology and rescue”, which has a nice ring to it, and even manages to make going through dusty boxes in dustier basements and typing in the original (often handwritten) observations sound glamorous and exciting. It’s not a simple task though:
“All my attention for recent years has been directed to that branch of meteorology connected with ascertaining the mean temperature of Lower Canada. I had not made up my mind as to the fact of the climate having materially altered but was impressed generally with the belief that the climate had improved, or become warmer, as it had increased in population and cultivation … I resolved to make diligent search for such records as might be found in the Province, in order to answer this interesting question. The difficulty of this experience was even greater than I had anticipated. Few individuals had turned their attention to this (even now) infant science, at a period sufficiently removed to bear comparison with the present, and of those which I was fortunate enough to discover, many were unsuitable from the irregular manner in which they were kept … None but the most zealous meteorologist knows how very difficult it is to obtain observations in this science which can be depended upon.”
John Samuel McCord, acc. 0882, McCord Museum of Canadian History Archives, circa 1838.