Trends and climatic variability in the Chilean viticultural production zones: three decades of climatic data (1985-2015)

Chile is characterized by offering high-quality vitivinicultural products and for its renowned viticultural valleys. At today, Chile has been considered vulnerable to climate change, which has brought a major concern to the national vitiviniculture. This research aimed to analyze the trends and climatic variability of the Chilean viticulture over three decades (1985-2015), evaluating meteorological, bioclimatic and risk indices in forty-seven stations. Meteorological data indicated that the warmest zone was Atacama, while the coldest was Aysén. The rainiest region was Austral, while the driest was Arica y Parinacota. Growing-season indices (GST, GDD and HI) showed that Central Valley was warmer than Arica y Parinacota, whereas, this latter, presented higher sum of spring temperatures (SONMean and SONMax). Atacama presented the highest risk for T>30°C, whereas Central and South Valleys for T>35°C. The highest frost risk was in Aysén, while the lowest in Arica y Parinacota. In general, Min T decreased by 0.33 ºC, while Max T increased by 0.83ºC. None of the trends for PP presented statistical significance. GST, GDD, HI, BEDD, SONMean and SONMax increased by 0.58ºC, 118.29 heat units, 140.57 heat units, 79.72 heat units, 8.42 heat units and 45.17 heat units, respectively, while CI decreased by 0.19ºC. Some stations that presented negative trend on CI coincided to the highest Max T. Locations in Coquimbo and Aconcagua valleys changed from intermediate to warm climate. Locations from Coquimbo and Central valleys changed from warm to hot climate. Quilaco changed from cool to warm climate, while Osorno changed from without classification to cool climate. PCA analysis reported that meteorological variables were related to the distance of the site to the Pacific Ocean. This information is of importance for the national industry and may allow to define mitigations strategies facing global warming.