Application of the WRF mesoscale model to investigate weather and climate variability in vineyard regions

Grapevines are highly sensitive to environmental conditions, with variability in weather and climate (particularly temperature) having a significant influence on wine quality, quantity and style. Improved knowledge of spatial and temporal variations in climate and their impact on grapevine response allows better decision-making to help maintain a sustainable wine industry in the context of medium to long term climate change. This new knowledge can be used in both operational decisions such as pruning regimes, canopy management, and response to frost and disease occurrence, and longer-term decisions such as selecting grape varieties to suit environmental conditions.
This presentation describes recent research into the application of mesoscale weather and climate models that aims to improve our understanding of climate variability at high spatial (1 km and less) and temporal (hourly) resolution within vineyard regions of varying terrain complexity. The ability of the Weather Research and Forecasting (WRF) model to simulate the weather and climate in vineyard regions has been evaluated in South Africa, New Zealand and France. The results of research in the complex terrain of New Zealand are summarised here, using the Marlborough region as a case study.
The performance of the WRF model in reproducing the temperature variability across vineyard regions is assessed through comparison with automatic weather stations. Coupling the atmospheric model with bioclimatic indices (e.g. Huglin, cool nights, Grapevine Flowering Véraison) also provides useful insights into grapevine response to spatial variability of climate during the growing season, as well as assessment of spatial variability in the optimal climate conditions for specific grape varieties. This improved knowledge of weather and climate variability in vineyard regions allows assessment of the current optimal/marginal status of the current grape varieties, and provides the basis for developing adaptation strategies in response to future climate change.