Mapping climate and bioclimatic indices at high-resolution in vineyard regions

Many of the world’s vineyard regions are located in regions of complex terrain, with the result there is significant local climate variation. The range of climatic conditions provides the opportunity for wine producers to readily adapt to the increasing influence of global warming on wine production by adjusting grape varieties and management practices to suit local environmental conditions. However, to allow this to happen, knowledge of fine scale variations in climate in vineyard regions needs to be improved. Our recent research has demonstrated that mesoscale atmospheric numerical models can be used to provide a good representation of the small-scale variations of climate in such regions of complex terrain. They are particularly useful for mapping mean daily temperature, which is the main variable used to derive bioclimatic indices of relevance to grapevine growth (such as the Huglin, Winkler, Grapevine Flowering Véraison and cool nights indices).

This paper provides examples of recent research in which the Weather Research and Forecasting climate model has been used to improve our understanding of climate variability at high spatial (1 km and less) and temporal (hourly) resolution within vineyard regions of different terrain complexity (e.g. in South Africa, New Zealand and France). Model performance is evaluated through comparison with automatic weather stations. The model output is used to investigate the spatial variability of derived bioclimatic indices and climatic hazards such as the occurrence of late frost, at high resolution across vineyard regions. Further analysis has also provided useful insights into grapevine response to spatial variability of climate through the prediction and mapping of dates of the key phenological stages of flowering and véraison.”.