Terroir 2010 banner
IVES 9 IVES Conference Series 9 Using atmospheric and statistical models to understand local climate and assess spatial temperature variability at a fine scale over the Stellenbosch wine district, South Africa

Using atmospheric and statistical models to understand local climate and assess spatial temperature variability at a fine scale over the Stellenbosch wine district, South Africa

Abstract

Atmospheric and statistical models were used to increase understanding of potential climatic impacts, resulting from mesoscale physical processes that cause significant temperature variability for viticulture within the Stellenbosch Wine of Origin district. Hourly temperature values from 16 automatic weather stations and 40 tinytag data loggers located in the vineyards were analysed. The 5th of March 2009 was selected as an example to study the cooling potential of the terroirs in radiative weather conditions during grape ripening time. Differences reached more than 10°C between vineyards and can be considered as significant for viticulture. Numerical simulations using the Regional Atmospheric Modeling System were performed. Results for a horizontal grid resolution of 200 m over the Stellenbosch wine region for the 5th of March 2009 showed that the temperature difference was due to cool air accumulation with land and downslope breezes. Surface temperature data recorded in the vineyards were used to produce, by means of multicriteria statistical modelling, which took environmental factors into account, a map of spatial distribution of the daily minimum temperature at a fine scale (90 m). The use of the two models represented an interesting tool to help in identifying the cooling potential of locations for viticulture and, at a later stage, studying the impacts of climate change at fine scales.

DOI:

Publication date: October 6, 2020

Issue: Terroir 2010

Type: Article

Authors

V. Bonnardot (1), V. Carey (2), M. Madelin (3), S. Cautenet (4), Z. Coetzee (2), H. Quénol (1)

(1) COSTEL-LETG, UMR 6554 CNRS, Université Rennes2, Place du Recteur H. Le Moal, 35043 Rennes
(2) Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1 Matieland 7602, RSA.
(3) PRODIG, UMR 8586 CNRS, Université Paris 7 Diderot, 2 rue Valette, 75005 Paris, France.
(4) LaMP, UMR 6016 CNRS, Université Blaise Pascal, 24 Avenue des Landais, 63177 Aubière, France

Contact the author

Keywords

Atmospheric modelling, statistical modelling, cooling potential, vineyard, South Africa

Tags

IVES Conference Series | Terroir 2010

Citation

Related articles…

Modeling sugar accumulation dynamics of a wide variety of grape cultivars (Vitis vinifera L.)

Climate change is a major challenge in wine production. The IPCC (2014) projected that by the end of the 21st century average temperatures will increase by 1-3.7°C. Consequently, harvest dates could advance by approximately 30 days. A general observed trend is the increase in berry sugar content and decrease in organic acids, posing challenges for winegrowers. Variability among cultivars is a precious resource to adapt viticulture to a changing environment.

Moderate wine consumption – part of a balanced diet or a health risk?

Consumption of wine/alcoholic beverages remains a topic of great uncertainty and controversy worldwide. The term “no safe level” dominates the media communication and policy ever since population studies in 2018 [1,2] were published, which denied the existence of a J-curve and suggested that ANY consumption of an alcoholic beverage is harmful to health. The scientific evidence accumulated during the past decades about the health benefits of moderate wine consumption, were questioned and drinking guidelines considered to be too loose.

DOSAVIÑA® A new app for a more sustainable use of plant protection products in vineyard

Aims: DOSAVIÑA® was developed with the aim of helping farmers to determine optimal volume rates for spray applications in vineyards. The final developed tool is a good example of bringing research to end users.

Mechanical fruit zone leaf removal and deficit irrigation practices interact to affect yield and fruit quality of Cabernet Sauvignon grown in a hot climate

Cabernet Sauvignon is the top red wine cultivar in CA, however, the hot climate in Fresno is not ideal for Cabernet Sauvignon, particularly for berry color development. Fruit-zone leaf removal and irrigation were studied previously to have the significant effect on grape yield performance and berry quality. But the timing of leaf removal and the timing of irrigation are still inconclusive. Also, mechanical fruit-zone leaf removal is relatively new in CA. Our study aims to identify the interactive effect of mechanical fruit-zone leaf removal and irrigation on Cabernet Sauvignon’s yield performance and fruit quality and find the ideal timing of leaf removal and irrigation to maximize the berry color while maintaining the sustainable yield level.

Mechanisms responsible for different susceptibility of grapevine varieties to flavescence dorée

Flavescence dorée (FD) is the most serious grapevine yellows disease in Europe. It is caused by phytoplasmas which are transmitted from grapevine to grapevine by the leafhopper Scaphoideus titanus.