tailieunhanh - AN IMPROVED METHOD OF CONSTRUCTING A DATABASE OF MONTHLY CLIMATE OBSERVATIONS AND ASSOCIATED HIGH-RESOLUTION GRIDS

These limitations arise because the P2P world is lacking in the areas of semantics, data transformation, and data relationships, yet these are some of the core strengths of the data management community. Queries, views, and integrity constraints can be used to express relationships between existing objects and to define new objects in terms of old ones. Complex queries can be posed across multiple sources, and the results of one query can be materialized and used to answer other queries. Data management techniques such as these can be used to develop better solutions to the data placement problem at the heart of any P2P system design:. | INTERNATIONAL JOURNAL OF CLIMATOLOGY Int. J. Climatol. 25 693-712 2005 Published online in Wiley InterScience . DOI AN IMPROVED METHOD OF CONSTRUCTING A DATABASE OF MONTHLY CLIMATE OBSERVATIONS AND ASSOCIATED HIGH-RESOLUTION GRIDS TIMOTHY D. MITCHELLa and PHILIP D. Jones a Tyndall Centre for Climate Change Research School of Environmental Sciences University of East Anglia Norwich NR4 7TJ UK b Climatic Research Unit School of Environmental Sciences University of East Anglia Norwich NR4 7TJ UK Received 3 March 2004 Revised 19 January 2005 Accepted 24 January 2005 ABSTRACT A database of monthly climate observations from meteorological stations is constructed. The database includes six climate elements and extends over the global land surface. The database is checked for inhomogeneities in the station records using an automated method that refines previous methods by using incomplete and partially overlapping records and by detecting inhomogeneities with opposite signs in different seasons. The method includes the development of reference series using neighbouring stations. Information from different sources about a single station may be combined even without an overlapping period using a reference series. Thus a longer station record may be obtained and fragmentation of records reduced. The reference series also enables 1961-90 normals to be calculated for a larger proportion of stations. The station anomalies are interpolated onto a grid covering the global land surface excluding Antarctica and combined with a published normal from 1961-90. Thus climate grids are constructed for nine climate variables temperature diurnal temperature range daily minimum and maximum temperatures precipitation wet-day frequency frost-day frequency vapour pressure and cloud cover for the period 1901-2002. This dataset is known as CRU TS and is publicly available http . Copyright 2005 Royal Meteorological Society. KEY