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The voyage begins..

May 3, 2011

This post marks the beginning of a three year project called ARCdoc. The project, which has been generously funded by the Leverhulme Trust, seeks to clarify and enhance our knowledge of climate change in the Arctic region using historical marine meteorological observations made on board Royal Navy,whaling and commercial (The Hudson’s Bay Company) ships, between 1750 and 1850.

The Arctic constitutes a key part of the global climate system, responding to, and in turn influencing conditions beyond its boundaries. However, the region’s complex climatic character, although of global significance, is amongst the most poorly chronicled and its climatic history therefore, remains poorly understood.

This project seeks to address this problem of data deficiency by extracting weather information from the largely overlooked logbooks kept by the ships of the Royal Navy, Whaling industry and the Hudson’s Bay Company. The study period commences with the earliest logbooks (1750) and concludes with the advent of organised gathering of marine observations in the mid-nineteenth century.

All the logbooks contain non instrumental observations of wind force and wind direction, supplemented by additional information on the state of the sea, sea ice cover and the prevailing weather conditions. Preparation of instrumental observations (air pressure and temperature) were not common practice until the mid nineteenth century, although there are exceptions: those being the Hudson’s Bay Company logbooks, which start to contain observations in the early part of the 180o’s and in the logbooks of Royal Navy discovery ships voyaging in search of the North West Passage, from 1819 onwards.

The geographical range of the study region includes the seas around Greenland, including the Denmark Strait, Labrador Sea and Davis Strait. Records from Whaling vessels in Baffin Bay take the study region west of Greenland to nearly 80N. In addition, records from much of the ‘sub-Arctic’ Atlantic, north of 55N allow the project to include notable quantities of data from the far North Atlantic, which have never been used before.

These marine meteorological observations will provide an improved picture of the Arctic climate (wind circulations, ice coverage, temperature and air pressure) between 1750 and 1850, allowing us to set our findings against the current understanding of conditions at the time and in doing so, provide for more reliable predictions of future climates based on models that require calibration against such ‘historic’ information.

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4 Comments leave one →
  1. May 23, 2011 2:39 pm

    New job, new blog – sounds good 🙂

    Sarah

  2. May 23, 2011 2:46 pm

    How do you plan to normalise this data to make any serious use of it since it is recorded by relatively untrained observers, is mostly observational rather than instrumental and has no guarantee of correct and standardised exposure for such things as temperature readings?

    • catharineward permalink
      June 19, 2011 12:56 pm

      Thanks very much for your comment. The majority of the logbook observations (wind force, wind direction and weather) during the period 1750-1850 are non instrumental (observational), and thus the accuracy of those observations does indeed depend upon the judgement of the recording officer. However these recording officers were in no way untrained. The keeping of a logbook served not only as an official account of the ship’s management but also as a navigational tool, and thus were kept only by seasoned and experienced officers, tutored in their craft.
      In the age of sail, recording officers were assiduous in their recording of wind force and wind direction, as this was needed to assess the degree to which they influenced the vessel’s course and speed.
      Wind directions were gauged by reference to the ship’s compass and from the behaviour of the sails and flags, and the movement of the waves and wind strength by reference to the state of the sea and the effect that wind has on the ship’s superstructure.
      Even today it is commonplace for VOSs (Voluntary Observing Ships) to report important meteorological data based on just such judgment-based observations. The published advice to present observers could apply to those of the 18th and 19th centuries:

      Non-instrumental observations are very important and, being estimates, they are
      dependent upon the personal judgement of the observer. This judgement is the product of training and experience at sea, together with practice in making the observations.
      (Meteorological Office, 1977, p.37).

      These observations will need, of course, to be normalised before they can be analysed. The Beaufort scale did not come into widespread use until 1830s, so the team will need to transform wind strength judgements into the more familiar terms of the Beaufort Scale. The team have however, established a methodology for doing this: please see the CLIWOC project Climatic change special edition for papers relating to transformation, accuracy and consistency of ship’s logbook weather observations (Wheeler, 2005).

      The Royal Navy did not begin to make systematic instrumental observations until the middle of the 19th century, but an exception to this can be found in logbooks kept onboard RN ships voyaging in search of a NW passage from 1818 onwards. The Admiralty and the Royal Society saw these expeditions as a means to advance the physical sciences, including meteorology. As such, the expeditions were furnished
      with the best instruments of the time, and measurement errors are expected to be small (Ward and Dowdeswell, 2006), but changes in observing practices will produce some changes. A detailed discussion of known biases relating to these observations can be found in Brohan et al., 2010.

      References:

      Brohan, P., Ward, C., Willetts, G., Wilkinson, C., Allan, R., and Wheeler, D., 2010. Arctic marine climate of the early nineteenth century. Clim. Past, 6, 315-324

      Ward, C. and Dowdeswell, J.A., 2006. On the meteorological instruments and observations made during the 19th Century exploration of the Canadian Northwest Passage. Arctic, Antarctic and Alpine Research, 38, p. 454-464.

      Wheeler, D., 2005: An examination of the accuracy and consistency of ships’ logbook weather observations and records. Climatic Change, 73, 97-116

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