Increasing cloud cover in the 20th century: review and new findings in Spain
dc.contributor.author
dc.date.accessioned
2013-10-16T13:07:27Z
dc.date.available
2013-10-16T13:07:27Z
dc.date.issued
2012
dc.identifier.issn
1814-9324
dc.identifier.uri
dc.description.abstract
Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC) and cloudy types; most of these studies focus on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain) since the second half of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. These estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in
oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866–2010 period, is a highly remarkable (and statistically significant) increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in lin with the majority of the trends observed in many areas of the world in previous studies, especially for the records before the 1950s when a widespread increase of TCC can been considered as a common feature
dc.description.sponsorship
This research was supported by the Spanish Ministry of Science and Innovation project NUCLIERSOL (CGL2010-18546). The first author was supported by a post-doctoral fellowship from the "Comissionat per a Universitats i Recerca del Departament d'Innovacio, Universitats i Empresa de la Generalitat de Catalunya" (2009 BP-A 00035)
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
European Geosciences Union (EGU), Copernicus Publications
dc.relation
info:eu-repo/grantAgreement/MICINN//CGL2010-18546/ES/LAS NUBES Y SUS EFECTOS SOBRE LA RADIACION: DEL ESTUDIO DE SITUACIONES A ESCALA LOCAL AL ANALISIS CLIMATOLOGICO DE ALCANCE GLOBAL. INTERACCIONES CON EL AEROSOL ATMOSFERICO/
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Reproducció digital del document publicat a: http://dx.doi.org/10.5194/cp-8-1199-2012
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Climate of the Past, 2012, vol. 8, p.1199-1212
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Articles publicats (D-F)
dc.rights
Attribution 3.0 Spain
dc.rights.uri
dc.title
Increasing cloud cover in the 20th century: review and new findings in Spain
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.embargo.terms
Cap
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
017149
dc.contributor.funder
dc.relation.ProjectAcronym
dc.identifier.eissn
1814-9332