Long-term changes in extreme temperatures and precipitation in Spain

Abstract

The development of the Spanish daily adjusted temperature series (SDATS) and the Spanish daily adjusted precipitation series (SDAPS) datasets in the framework of the European Community (EC)-funded project EMULATE (European and North Atlantic daily to MULtidecadal climATE variability) enabled the assessment of long-term annual changes of extreme temperature and precipitation indices over peninsular Spain for the period 19012005. Within this framework, a set of procedures was developed to generate long-term (18502005) daily adjusted temperature and precipitation series and to use them to assess changes in climatic extremes. The present report describes details of the data employed to analyze the behavior of Spanish climate extremes and discusses the results of investigations into the annual changes in selected indices that occurred during the 20th century: exceedances of upper and lower percentiles of daily maximum (Tmax) and minimum (Tmin) temperatures, cold-spell duration index (CSDI), warm-spell duration index (WSDI), daily rainfall (R) exceeding the 95th and 99th percentiles, simple daily intensity index (SDII), and greatest 1- and 5-day total precipitation. Upper and lower temperature percentiles increased during the 20th century over mainland Spain, but changes in daytime extreme temperatures were larger than changes in night-time extreme temperatures. This pattern, however, shifted slightly in the recent period of strong warming, with more similar rates of change among daytime and night-time extreme temperatures. Changes in extreme precipitation indices were not as evident as those in extremetemperature indices, but there was a tendency towards heavier precipitation.