Tuesday, May 26, 2009

Weather: Early Observations I

Map from http://www.historyoftheland.org/
Alexander Henry, known by some as Henry the Younger to distinguish him from his well-known uncle, was a prominent figure in Canada's North West Fur Company during the late eighteenth and early nineteenth centuries. He spent considerable time exploring, hunting, and trapping in the Red River Valley and helped establish old Fort Pembina just across the river from present-day St. Vincent, Minnesota. A literate man, Henry was one of the first pioneers in the region to keep a journal that contained detailed weather observations. Documents suggest that he established his trading post on the same ground used by Charles Chaboillez1 in 1797. Chaboillez was a partner in the North West Fur Company who later supervised a company post on Lake Superior. He, too, kept a journal of his activities near the junction of the Pembina and Red rivers, but it lacked the weather and climate detail of Henry's.

Henry traded alcohol, tools, and weapons with the native americans who lived near Fort Pembina: the Dakota tribes of the plains on the western side of the river (later North Dakota) and the Ojibwe on the eastern side of the river. He was meticulous in keeping daily weather observations from September 1807 through June 1808.

The landscape of northwestern Minnesota was vastly different during Henry's time. Buffalo and beaver were abundant, as were red deer, moose, bear, and wolves. The wide river valley was populated with tall prairie grasses and old trees (oak, birch, maple, pine, poplar, and willow, among others) and dotted with wetland areas (sedge and marsh.) A mosaic of trails and paths devoid of vegetation weaved across this prairie where the abundant buffalo herds trampled and compacted the heavy, wet soils. In addition to hunting buffalo and red deer for food, Henry and his men had good luck fishing the Red River, which was full of sturgeon.

Henry prized his daily journal of weather and nature observations, three volumes of which were published in 1897. Though some historians consider the Henry documents to be dry and humorless, for climatologists they are a treasure trove for use in evaluating the weather behaviors of a bygone era. His records are also noteworthy because they include climate descriptions of the area before the end of the Little Ice Age (1850)2, a relatively cooler period for the northern hemisphere.

The Minnesota State Climatology Office has archived records of Henry's daily weather observations from September 1, 1807, to June 1, 1808. These include morning, midday, and evening observations of air temperature, wind, and sky condition, along with remarks describing the day's character. The following tables show comparisons between Henry's observations and current published climatic normals at Pembina, North Dakota, and at Hallock, Minnesota.

In general the tables show that the climate of the Red River Valley during 1807-8 ws similar in temperature to today's climate, with one major exception: April was a remarkably warm month, producing a rapid and early break-up of ice on the Red River, with associated flooding. Henry noted the return of migratory birds as early as April 4 and 5. He also brags of enormously successful sturgeon fishing: on April 24 he "set a sturgeon net and caught 3 instantly." A more detailed book shows that the lowest temperature measured by Henry during the winter was -30F on February 18, quite close to the modern era's usual lowest winter temperature, which ranges from -30 to -35F at Hallock and Pembina. The coldest spell in February 1807 also coincided with some of the strongest winds Henry noted, likely producing wind-chill conditions in the -50F or colder range. However, the winter of 1807-8 saw only 43 days with temperatures below zero degrees Fahrenheit. Modern records from Pembina and Hallock both show an average of 67 days each winter with such temperatures. Thus, Henry and his men did not have to endure the persistent cold that Mother Nature usually brings to the area.

From Minnesota Weather Almanac, by Mark W. Seeley (Published by Minnesota Historical Society © 2006)

1 - Charles Chaboilliez (Chaboille/Chaboillier) IV: (b.1772, Montreal - d.1812, Mascouche, Lower Canada) Charles was the son of Charles III & Marguerite Larcheveque and he married Jessy Bruce in 1811 at Quebec. Their children were; Charles V (1805-1863), Jean, Marguerite, Pierre (b.abt.1808) (m.Josette bef.1841), & Louise (b.1809)(m.Allan Morrison).

In May of 1791 he was hired by Joseph Frobisher for 4 years as a North West Company clerk. He was at the Cumberland House & Ile-a-la-Crosse NWC posts until he was assigned to the Assiniboine & Red River Departments in 1796. While trading at the mouth of the Pembina River he kept a journal until the summer of 1798. The list of his voyageurs include: Dubois, Chaurette, Roy, Bercier, Desjarlaix, Sauve, Bourret, Francois Delorme, Richards(the HBC trader that left that company to join Chaboilliez), Mineclier, Le Duc, Bertrand, Chevalier, Allard, Bibeau, Pouilliot, Foumas, Lambert, Cadotte & Hyversoit. On 14 Mar 1798 the David Thompson exploration expedition arrived at the Pembina post and 7 days later Chaboilliez accompanied Thompson to Vincent Roy's NWC post south of Pembina on the Forest River. In 1799 he became a partner in the NWC and was given charge of the Lower Red River Department for the company.

On October 31 1804 Lewis & Clark wrote to Chaboilliez from the Upper Mandan village on the Missouri; "...we met with Mr.Hugh M'Cracken, who informed us that he was in some measure employed by you in behalf of the North West Company, traffic with the natives of this quarter...we have determined to fortify ourselves, and remain the ensuing winter...If, sir, in the course of the winter, you have it in your power to furnish us with any hints in relation to the geography of the country, its productions, either mineral, animal or vegetable, or any other information...we should feel ourselves extremely obliged...". - From Trade Goods

2 - The 'Little Ice Age' was an interval between about AD 1500 and 1850, characterized by advancing glaciers in mountainous regions of Europe and western North America. However, it is unclear whether this cool moist period was truly global in extent, or how it was manifested in other regions with different climatic controls. A high-resolution reconstruction of salinity fluctuations in Devils Lake, North Dakota, based on fossil diatoms, ostracode-shell geochemistry, and bulk-carbonate geochemistry, indicates that saline conditions prevailed throughout much of the recent past. These results suggest an arid climate in the northern Great Plains throughout the 'Little Ice Age' and that during this interval climatic gradients between the Great Plains and regions to both the east and west may have been quite steep. - From 'Little Ice Age' aridity in the North American Great Plains: a high-resolution reconstruction of salinity fluctuations from Devils Lake, North Dakota, USA by Sherilyn C. Fritz, Daniel R. Engstrom, and Brian J. Haskell (The Holocene, Vol. 4, No. 1, 69-73 (1994))