This page contains the documentation for the TYN CY 1.1 data-set, and comprises:
9th May 2003
Additional information on time-series analysis has been added. This data-set should only be used for time-series analysis (e.g. trends or regression) with the greatest of care. This data-set is based on the CRU TS 2.0 grids, and the discussion of the limitations on the use of that data-set is relevant here.
8th May 2003
This version is an update to TYN CY 1.0. Note the changes.
The data set described here provides a summary of the climate of the 20th century for 289 countries and territories.
The relevant changes for this country data-set are as follows:
This data set is intended for use in trans-boundary research, where it is necessary to average climatic behaviour over a wide area into statistics that are representative of the whole area. The user should note that any single country may contain substantial spatial variations of climate within it, and that climate changes over time.
This data set should not be used to represent climate at a point, or for sub-regions of the countries and territories supplied here. If climate data is required for points or sub-regions, enquiries should be made to the national meteorological agency of the country concerned.
This data-set should only be used for time-series analysis (e.g. trends or regression) with the greatest of care. This data-set is based on the CRU TS 2.0 grids, and the discussion of the limitations on the use of that data-set is relevant here.
Please note that the standard deviation data may include influences from the changes over time in the station networks contributing to the underlying grids (see discussion). Therefore, particularly for smaller countries and data-sparse regions, the 'standard deviation' presented here may not be entirely climatic, but also a function of the number of observations.
The credibility of the data set rests upon observed grids previously constructed (CRU TS 2.0 - see details of the original data). The work of this author was to aggregate the grid box values into averages representing countries and territories (see details of the data processing).
For many countries, the accuracy is better for more recent decades than for earlier decades of the 20th century (although data is provided wherever possible). In addition, the useful precision of the data may be less in earlier decades of the 20th century (although the recorded precision is constant throughout). For some variables and countries there is insufficient data to make a reasonable estimate of year-to-year variations in the early part of the 20th century; in such cases, the values recorded are 'relaxed' towards the average from 1961-1990, and therefore are not representative of the real-world year-to-year variations.
One climatic season (December-February) overlaps from one calendar year to the next. The value we supply begins in the December of the year recorded, and ends in the February following the year recorded. Therefore the last year recorded always contains the missing value (-999.0) in the DJF column.
Further information may be obtained from the research paper published in Area. An electronic version is available.
The average climate is available as:
The author bears no responsibility for the accuracy of the data set. The countries listed below include a variety of sovereign states, dependent territories, and disputed territories. No political statement is being made by the inclusion or exclusion of a particular territory, or by the labelling of a particular territory by a particular name.
The original data took the form of a value for each month and each box on a 0.5 degree latitude / longitude grid (CRU TS 2.0). We assigned each box to a single country. For each country we calculated the weighted mean of the values from its constituent grid boxes for each month in turn. Each grid box was weighted by surface area, using the cosine of the latitude. The seasonal and annual values are the means of their constituent months.
Station observations were first collected by national meteorological, hydrological and related services, and were acquired through the free and unrestricted exchange of meteorological and related data. These observations were gridded. The gridded data-set is publicly available, and is being published in a peer-reviewed scientific journal:
Mitchell, T.D., Carter, T.R., Jones, P.D., Hulme,M., New, M., 2003: A comprehensive set of high-resolution grids of monthly climate for Europe and the globe: the observed record (1901-2000) and 16 scenarios (2001-2100). Journal of Climate: submitted.