An extended Mann-Kendall’s tau coefficient for the analysis of projected changes in temperature and precipitation in southern Spain

Abstract

This paper presents an innovative extension of Mann-Kendall’s coefficient, called the Extended Mann-Kendall’s tau coefficient, aimed at exploring future climate trends in greater depth and detail. This method enables a more complete integration of multiple climate projections (CMIP6) and scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5), offering a more holistic view of possible future changes in climate. This methodology has been implemented to analyze changes in different variables related to temperature (maximum temperature (TMax), minimum temperature (TMin), extreme heat waves (EHW), heat waves (HW), tropical nights (TN), and annual rainfall (AR) in Andalusia (Spain) between 2010 and 2100 and considering the CMIP6 models for all scenarios. As a result, both temperatures and rainfall show a temporal evolution in which notable and forceful changes are identified. Evidence of a general trend toward higher temperatures is observed. In addition, a reduction in annual rainfall, which poses additional challenges in terms of water management and food security, is identified. The geographic distribution of these changes reveals complex patterns. Large contrasts between inland and coastal areas, along with a dichotomy between areas exposed to Atlantic and Mediterranean influence, are observed.