20 years of data rescue initiatives at the Meteorological Service of Catalonia

Since the restoration of the Meteorological Service of Catalonia (SMC) in 2002, data rescue, quality control and homogeneity analysis of climate series have been one of the main focuses of the Climatology Area ofSMC. Working with continuous series, having a wide temporal coverage and ensuring good spatial density are essential for accurately characterizing climate change and variability.To achieve this goal, significant effort must be invested in data preservation and rescue, identifying meteorological series of interest, and ensuring good digitization, transcription and cataloging. This work describes the process of data rescue at SMC, from identifying meteorological significant collections, to entering all data into the historical base of SMC, while preserving original documentation.Collections with meteorological documentation vary widely.Historical newspapers. In recent years many state, provincial and local archives in Catalonia have tried to digitize historic newspapers.SMC has identified over 175 periodicals containing meteorological observations and metadata information. Private archives. Several private archives, both religious and corporate, have been found to contain documentation related to meteorological observations. Observers or their relatives who have preserved the original documentation, contact SMC for the preservation. When a collection arrives at SMC, there are essentially four possibilities. (1) First, it may involve a temporary transfer of documentation, in which case it is digitized and returned to the owner. (2) Alternatively, if photography of the documentation is not permitted, it may be necessary to visit the location and transcribe the data. (3) A third option is that, once the documentation is digitized, it is restored if necessary and then entered into the National Archive of Catalonia through an agreement with SMC to ensure optimal preservation conditions. (4) Finally, data may be provided directly by the observer (already digitized or not), which can then be entered directly into the historical database.Once the data is extracted, any existing gaps in the historical database are filled, and coverage periods of the stations are extended. Data from previously unpublished stations are also incorporated, enriching and enhancing our ability to monitor variability and climate change in Catalonia.