| This project’s objectives are based
on the climatic information contained in ships’ logbooks for the period
1750 to 1850. Officers on board eighteenth and nineteenth century
sailing vessels maintained detailed log books of the ships’ activities
and management. Included within these records were observations of
the current weather. These observations were made at least three times
daily and were used as an indispensable aid to navigation in a period
before reliable methods of determining longitude were widely available.
We are fortunate that many thousand such log books have survived.
This project concentrates on those held in British, Dutch, French,
Spanish and Argentinean archives. These collections contain the vast
majority of extant logbook material. Most of the logs are from vessels
engaged in military or official government activities, but a significant
number have also survived from the ships engaged in the Spanish Postal
Service and the quasi-governmental enterprises of British, Dutch and
French trading companies. The use of logbooks from these sources,
with their interests in different parts of the World, ensures a near-global
coverage of oceanic information. |
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The recorded data are concerned with wind direction and
wind force as these two elements more than any others contributed to the
speed and direction of the vessels. Other weather elements were also recorded
such as precipitation, fog, ice cover, state of sea and sky. Although
non-instrumental (some temperature and air pressure records begin to appear
in the nineteenth century but they are relatively few in number), the
data have been shown by the small scale studies thus far undertaken to
be reliable and accurate. They can be subjected to statistical analysis,
used for synoptic reconstructions and for scientific interpretation and
scrutiny.
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The log books represent a hitherto little
explored but potentially important source of oceanic climatic information
for a period before the establishment of networks of instrumental
observatories. The abstraction, digitisation and analysis of these
data will make a significant contribution to our knowledge and understanding
of global and regional climatic variation. |
Objective
1
To produce and make freely available
for the scientific community the World’s first daily oceanic climatological
database for the period 1750 to 1850.
The database will contain climatological information for
the North and South Atlantic, the Indian and the Pacific Oceans. Entries
will be made chronologically day by day but will include identification
by geographic location. Information on wind direction, wind force and
other recorded weather elements will be included. Sufficient log books
exist for a daily record of the observations for each the oceanic regions
to be abstracted. Each entry could contain up to ten items of regularly
recorded information with, in total, nearly one million, entries. The
database will be designed to allow for later additions as other sources
become available and for easy abstraction of information/data blocks specified
by the user. It will be supported by a substantial body of metadata focusing
on background material such as the details of the vessel in question,
the recording officer and the purpose of the voyage.
Objective 2
To realise the potential of the database
to provide a better knowledge of oceanic climate variability over the
study period.
It is important not only to produce but to utilise the
database to improve our knowledge and, ultimately, understanding of climatic
variability over the oceans between 1750 and 1850. Several further objectives
fall under this broad heading for this critical, pre-industrial and, as
far as oceanic climates are concerned, pre-instrumental period.
Objective 2a.
To prepare summary and derivative measures from the database to
complement and integrate with other contemporary series.
A number of climatic series can be derived from the database.
These can be further summarised at the seasonal, annual, decadal and multi-decadal
time scales. The geographic coverage of the raw data allows for global
as well as regional summaries. These derived series can be usefully compared
with contemporary, land-based data to shed light on regional climate responses
to changing conditions over the oceans. Much of this land-based data have
already been gathered under the auspices of various past EC projects.
Objective 2b.
To use the database to determine the character and scale of oceanic
climatic change and variability at various time scales during the final
stages of the pre-industrial period.
The rapidity and nature of climatic variations across
oceanic areas can be objectively identified. This is important because
the project’s data are drawn from the ‘pre-industrial’ period when anthropogenic
climatic control is widely regarded as absent and the results will aid
testing of general circulation models.
Objective 2c.
To extend the NAO record by reference to derived information from
the database.
Because of the abundance of data from the North Atlantic
region and its importance to furthering our understanding of European
climate, particular emphasis will be placed on the North Atlantic Oscillation
and how it manifests itself in the abstracted data. An index will be developed
to reconstruct the NAO record to 1750. Reference to contemporary land-based
data will shed light on the role of the NAO in governing European climates
between 1750 and 1850. Twentieth century data can be used to examine the
consistency of this relationship over the multi-decadal time scale.
Objective 3
To use the information to extend and
enhance existing oceanic-climate databases.
The proposers recognise that this project is relevant to
other research being undertaken. It offers the possibility of supplementing
and extending established data sets, in particular the world-wide Comprehensive
Ocean-Atmosphere Data Set (COADS), thereby extending the period of cover
backwards by a further century from its current starting point in the
mid-nineteenth century.
Objective 4
To disseminate the project’s findings
and to stimulate interest and awareness in this source with a view to
fostering its further development and realising its scientific potential.
This projects concentrates on British, Dutch, French, Spanish
and Argentinean log books. Most of these are sources that have already
been subject to preliminary examination. It is known that other sources
exist elsewhere in Europe that for reasons of accessibility, lack of opportunity
or appreciation of their scientific value, have not been exploited. An
important objective is to encourage work in these areas by fellow academics.
The most significant innovatory aspect of this work is
its exploration of a long-existing but relatively under-utilised source
of reliable scientific information, viz. ships’ log books from the late
eighteenth and early nineteenth centuries. Never before has this source
been exploited in the proposed degree of detail or over such a large number
of items and geographic range. Early work, making limited use of log book
data for purposes of pressure field reconstruction was carried out by
Lamb and Johnson (1966). Oliver and Kington (1970) drew attention to the
potential of log books for climatic research but only much more recently
have any steps been taken towards realising this potential, e.g. Landsberg
(1985).
The scientific work is poorly advanced however and developing
only in a few countries. The reasons for this are manifold but a prevailing
lack of awareness of the nature or existence of ships’ log books or of
their climatological contents has been a factor. In addition, the practical
tasks of abstracting detailed data from thousands of items are formidable
for any individual or small group. Archaic vocabulary, ambiguous terminology
and the absence of any international standards for weather terms as well
as the problems of calligraphy and language have also hindered the study
of this internationally-based source. More generally, a concern on the
part of some scientists regarding non-instrumental data may also be a
factor. Yet, as the widely-acclaimed works of Lamb (1995) and Ladurie
(1972) have demonstrated, such concerns are ill-founded and this project
aims to extend further the scientific application of historical data.
Current research using this source has thus far been limited
to case studies and specifically-focused analyses (e.g. Farrington et
al, 1998 and Catchpole, 1992). These have been useful in themselves and
have given a strong indication that the data source is both extensive
in terms of geographical coverage and reliable in the consistency and
accuracy of the climatic record. Other studies have also revealed how
the data can be used to produce either detailed daily synoptic reconstructions
or long series of climate records. Such relatively small-scale studies
could of course continue but the point has been reached when an attempt
at a more comprehensive exercise, drawing upon many log books over wide
areas and spanning collectively many decades, must be undertaken to realise
the potential of this unique part of the European heritage and to bring
it to the attention of the wider scientific community.
The second important innovative aspect of this project
is its concentration on oceanic areas. Past researches of the climates
of the eighteenth and nineteenth centuries have principally focused on
land-based data. Although a Danish project (Frydendahl. et al 1992) has
been carried out using digitized log book data for the early eighteenth
century the oceans have for the period 1750-1850 have yet to be examined
in detail. Whilst instrumental data of the character that are normally
associated with land-based observations, such as temperatures, rainfall
and air pressure, are so scarce as to render any comprehensive review
untenable, the data for wind direction and force can provide a reliable
reconstruction of wind flow and air pressure fields. Similar work using
more restricted sets of land-based wind data in Sweden are models in this
respect showing how wind flow data can be profitably interpreted within
a wider regional context (Jönsson and Holmquist, 1995). Indeed it can
be argued that such marine-based wind data are more reliably recorded
and more representative of synoptic-scale factors than are land-based
observations subject as they are to local influences.
Whilst attention will be devoted to the wind data, other
climatic variables are also available; precipitation, heavy fog and other
extreme occurrences such as ice cover and icebergs were consistently recorded.
These data will be included in the database. They will also contribute
to the preparation of time series information to identify significant
climatic events and periods. For example, although precipitation depths
are not recorded, wet and dry phases can be distinguished from the data
through the ‘rain days’ series. Whilst similar series have been already
assembled for many land-based sites no comparable undertaking exists for
oceanic areas.
This project, whilst innovative in many fundamental aspects
is at the same time part of the wider field of established climatic studies
where the state of the science is much more advanced. Close attention
will be given to examination of the climatic record revealed in the various
series. Comparisons with contemporary evidence from land-based observations
will be made in the search for a more comprehensive knowledge of climate
variation that has hitherto lacked a detailed oceanic climatic element.
The series will also be examined for signals and teleconnections between
major areas of activity. The ENSO signal is perhaps the most widely sought
at present, but the North Atlantic Oscillation (NAO), if only because
of its profound influence on European climate, demands attention. In addition
the strength of the NAO signal is found over the sea and for the time
period embraced by the project now other direct observational data are
available for those areas. Finally, the project will formally extend existing
databases of which COADS (Woodruff et al, 1993) is the most apposite.
The log book data source provides the only current means by which such
extensions backwards through time can be confidently made.
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