Terroir 2004 banner
IVES 9 IVES Conference Series 9 Atmospheric modeling: a tool to identify locations best suited for vine cultivation. Preliminary results in the Stellenbosch region

Atmospheric modeling: a tool to identify locations best suited for vine cultivation. Preliminary results in the Stellenbosch region

Abstract

The choice of sites for viticulture depends on natural environmental factors, particularly climate, as grapevines have specific climatic requirements for optimum physiological performance and berry quality achievement. In the Stellenbosch wine-producing region, the complex topography and the proximity of the ocean create a variety of topoclimates resulting in different growth conditions for vines within short distances.
The Regional Atmospheric Modeling System (RAMS) was used to perform numerical simulations over the South Western Cape, for a period of 18 days during grape ripening (February 2000). Four 4 nested grids (25 km, 5 km, 1 km and 200 m of resolution) were used, the coarse grid being the computational domain (taking the large scale circulation into account), while the finest resolution (200m) focused on the vineyards south of Stellenbosch (taking the local circulations into account) in order to extrapolate climatic data at a fine scale. Data from the analysis file were extracted and remapped using the climatic thresholds for viticulture, thereby making the meso-scale atmospheric modeling system applicable to grapevine cultivation. Temperatures were grouped into different ranges that would affect the physiology of the vine.
These preliminary results identified locations near Stellenbosch according to the thermal stresses for specific days as well as their potential to meet the climatic requirements for optimum physiological performance of the vine. Three typical weather situations are described at the peak of the photosynthetic performance period (12:00), using results of the two finest grid resolutions (1 km and 200 m). Modeled hourly data were extracted from the analysis file in order to calculate the mean hourly temperature fields for a 16-day period (1-16 Feb 2000) and the mean data were then reintegrated into a GIS as an additional descriptive variable useful for terroir identification.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

V. Bonnardot (1), S. Cautenet (2), H. Beukes (1) and J.J. Hunter (3)

(1) ARC-Institute for Soil, Climate and Water, Private Bag X5026, Stellenbosch 7599, RSA
(2) Laboratoire de Météorologie Physique (UMR 6016-CNRS), Blaise Pascal University, 24 Avenue des Landais, 63177 Aubière, France
(3) ARC Infruitec-Nietvoorbij Institute for Fruit, Vine and Wine, Private Bag, X5026, Stellenbosch 7599, RSA

Contact the author

Keywords

List of different keywords (keyword1, keyword2, keyword3)

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Le cuivre sur raisins et moûts: dosage et intérêts de la mesure

Avec l’accroissement des surfaces viticoles conduites en Bio, la question de l’impact de la présence de résidus de cuivre (seul anti fongique autorisé dans l’UE dans ce cadre Règlementaire) sur le déroulement des fermentations et sur les qualités œnologiques et organoleptiques des vins s’est révélée de plus en plus cruciale.

Vinhos de talha: to pitch or not to pitch

In Alentejo, south of Portugal there is a traditional way of fermenting wines in clay vessels, known as “Vinhos de Talha”. Clay vessels were traditionally impermeabilized using pine pitch, creating a barrier between the fermenting must and the clay. Due to this unusual production technology that uses of clay vessels, instead of inox or wood vessels, “Vinhos de Talha” present unique characteristics increasingly appreciated by national and international consumers when compared with wine obtained by the said traditional methods of winemaking. Although the positive consumers feedback, there is little literature about the physical-chemical characteristics of these wines (Martins et al, 2018; Cabrita et al, 2018). This work aims to characterize the volatile composition of white wines produced in clay vessels with different coatings and to contribute to the knowledge and preservation of these wines that are a unique cultural heritage. Wine samples were produced during 2019 vintage from white grapes, using the traditional technology associated to these wines.

Hyperspectral imaging for precision viticulture

Precision viticulture aims to optimize vineyard management by monitoring and responding to variability within vine plots. this work presents a comprehensive study on the application of hyperspectral imaging (hsi) technology for monitoring purposes in precision viticulture. authors explore the deployment of hsi sensors on various platforms including laboratory settings, terrestrial vehicles, and unmanned aerial vehicles, facilitating the collection of high-resolution data across extensive vineyard areas.

Impact of winemaking processes on wine polysaccharides, improving by qNMR

Today the knowledge in terms of molecular composition of the colloidal matrix is ​​not enough in order to control its stability, according to the number of winemaking and wine stabilization processes. The physico-chemical processes during the winemaking change the composition and quantity of wine macromolecules. The goal today is to determine which analytical techniques will allow to discriminate these winemaking processes in order to better understand their impact on colloidal matrix stability as well as which molecules are responsible for its instabilities. METHODS: Wines obtained after conventional winemaking were subjected to different fining and chemical stabilization treatments. Different methods were used to investigate the wine macromolecular composition and stability after chemical stabilization, including quantitative and qualitative analyzes of total soluble polysaccharides by extraction under acidified ethanol, and by size exclusion separation as well as qNMR metabolomics. RESULTS: Observation of a slight difference at the quantitative level using classical analysis between the winemaking processes was observed as well as a strong discrimination by qNMR metabolomics.

Effect of Quercus Alba oak barrels from different forests on the polyphenolic composition of Tempranillo red wines

The species and origin used for red wine oak aging determines the physiological composition of the wood and thus the finished wines. In America, oak is grown primarily in the states of Virginia, Missouri, Kentucky, Oregon, Ohio, Minnesota, Wisconsin and California. The aim of this study was to analyze how the choice of barrels made with Quercus Alba oak from different geographic areas of the United States (Missouri, Kentucky, Ohio and Pennsylvania) influences the polyphenolic composition of Tempranillo red wines.