Bioclimatic indices in the north-eastern part of the Labrador Peninsula in the second half of the 18th century

The oldest meteorological data for the north-eastern coast of the Labrador Peninsula date to the second half of the 18th century. Weather observations were conducted by the Moravian Church who settled here in 1771 to establish the first Christian mission in a settlement called Nain.

Within the next few years, two more settlements were established: Okak (formerly “Okkak”) and Hopedale (formerly “Hoffenthal”). While conducting their mission, the Moravian Church engaged in, among other things, making meteorological observations of such elements as air temperature (°F), wind speed (on a scale 0–6) and wind direction (on an eight-direction compass rose). Each measurement was performed four times a day (8:00, 12:00, 16:00 and 20:00 local time).

Based on publicly available materials, three series of data were developed – one for each station. Meteorological observations at Nain were made for the period Sep 1776 – Jul 1786. During this time, there was one gap in the measurements from 12 to 30 Sep 1784. At Okak, observations were made without interruption for the period 16 Oct 1776 – 31 Aug 1786. At Hopedale, observations were made from 1 Oct 1782 to 16 Aug 1786. This series is less complete because it has occasional gaps in observations (from one observation per day to 3 days), as well as one longer gap extending from 01 Aug 1784 to 31 Aug 1785.

All available historical data were quality checked and corrected. Air temperature was converted to degrees Celsius. Wind speeds given on a scale of 0-6 were converted to m∙s^-1 using the Beaufort scale.

Three indices were used to assess bioclimatic conditions – Wind Chill Temperature (WCI), Wind Chill Index (WCI) and Insulation Predicted (Iclp). For this purpose, the Bioklima program was used (www.igipz.pan.pl/geoekoklimat/blaz/BioKlima.htm). Before calculating the indices, the wind speed was reduced to a height of 1.2 m above ground level, which corresponds to the average human chest height.