D1: growing environment: climate class, weather, and climate change 7

Question 1

Climate:

Answer 1

Annual pattern of temp, sunlight, rainfall, humidity and wind averaged out over several years (30 years)

** climate doesnt change frome one year to another, although it can alter over a period of decades

Question 2

Climate classifications:

Answer 2

1) Growing degree days (GDD)
2) hughlin index
3) mean temp of the warmest month (MJT)
4) Growing season temp (GST)
5) Köppen’s Classification

Question 3

GDD:

Answer 3

Heat summation during the growing season by Amerine and Winkler (1944)
Intended for the vineyards of California

EG:
July (16-10°c) x 31 days= 186
** do the same calculation of the other months in the growing season, than add together the totals to get the GDD

The GDD are grouped in five ranges:

• winklers zone 1 (lowest gdd) are cool
• ” zone V (highest gdd)

Question 4

hughlin index:

Answer 4

1) uses a similar formule to gdd, but differs in calculation as they take both the max and mean temp and the increased day length experienced at higher latitudes
2) split into ranges with the most suitable grape varieties mapped in each range

** this model is widely used in EU

Question 5

Mean temp of the warmest month (MJT)

Answer 5

1) Smart and Dry uses the mean temp of either July in the northern hemisphere and january in the southern hempisphere (Mean January/ july temp MJT)
2) as well as measures of continentality, humidity and hours of sunshine
3) divided in six bands to aid the description and communication, ranging from cold to very hot

Question 6

GST growing season temp:

Answer 6

1) Uses the mean temper of the growing season
2) grouped into climatic bands from cool to very hot

** very closely correlated to gdd and is easier to calculate

Question 7

Köppens classification:

Answer 7

1) created in 1900
2) broad terms: categorised under three headings: maritime, mediterranean and continental

3) consider both temperature and rainfall patterns
4) these categories apply the regions in temperate zones and not vineyards located in the tropics

Question 8

Koppen: maritime:

Answer 8

Low anual differences between summer and winter temp

• rainfall is evenly spread throughout the year
• Bordeaux

Question 9

Mediterranean:

Answer 9

1) Low annual differences between summer and winter temp
2) rainfall tends to fall in the winter months, giving dry summers
3) Napa valley and Coonawarra

Question 10

Koppens: continental:

Answer 10

1) more extreme differences between summer and winter temp

2) often have short summers and cold winters with temp rapidly changing in the spring and autumn (burgundy and alsace

Question 11

WSET uses the following ranges:

Answer 11

1) Cool climates: regions with an average GST of 16.5°c 62°f or below
2) moderate : gst of 16.5-18.5°c 62-65°f
3) warm: GST of 18.5-21°c 65-70°f
4) hot climates: gst in excess of 21°c 70°f

Question 12

Variations in temp and timing of rainfall can have significant influence on vine growth, grape ripening and subsequent wine style and quality:

Answer 12

1) extreme winter temp can lead to winter freeze
2) rapid increase of temp in spring can lead to even budburst, (with little chance of spring frost)

3) there is also a rapid drop in temp in autumn and therefore a shorter growing season

Question 13

In regions with warm summers:

Answer 13

1) the risk of not accumulating sufficient sugar in the grapes is reduced
* but grapes can have high sugar levels and low acidity levels by the time aroma compounds, colour and tannins have reached optimum ripeness
* * this can lead to wines with high levels of alcohol and low levels of acid

Question 14

in climates with cool growing season:

Answer 14

1) grapes may be too low in sugar and too high in acid in the coolest years
2) low annual differences in cool maritime or mediterranean climates mean that such climates often have long autums at suitable temp for ripening, extending the growing season

Question 15

Climates with even levels of rainfall or high levels such as maritime:

Answer 15

1) these are less likely to experience extreme water stress
2) too much water can cause excessive vine vigour
3) rain also increases humidity, so fungal disease which can be particularly problematic near harvest time
4) vines that are grown in climates that are cool, cloudy and rainy in late spring or early summer are also are also susceptible to poor flowering and fruit set

Question 16

Continentality:

Answer 16

1) measure of the difference between the annual mean temp of the hottest and coldest months

2) large bodies of water (lake, seas or oceans) heat up and cool down more slowly than landmasses
* therefore in winter they have a warming effect on the surrounding air and a cooling effect in the summer

3) regions far inland or are protected from ocean influences have high continentality and tend to be categorised as ‘continental’
4) regions near the coast or that are nearby a large body of water have low continentality and tend to be categorised as either maritime or mediterranean

Question 17

Weather is the annual variation that happens relative to the climatic average:

Answer 17

1) some regions experience greater variations than others
* Bordeaux 2007: region was cool, cloudy and wet during august, whereas 2003 high temp and near drought conditions were experienced

2) regions like central valley california are more predictable with hot, dry weather from one growing season to the next

Question 18

Weather in a particular year can influence sugar and acid levels and tannin and aroma ripeness.

Answer 18

This may have a subsequent effect on how the wines are made in the winere (eg adjustments to the must or wine may be benefical, greater extraction may be desirable for red wines in warm years to balance high alc levels etc..)

Question 19

In some wine styles, vintage variation is expected and often welcomed. in others such as non vintage sparkling wines and many high volume inexpensive wines where consumers are expecting the wine to taste consistent regardless of the year, vintage variation is not desirable and winemaking choices may be made that reduce any vintage variation in the final wine.

Answer 19

true

Question 20

Weather can also affect yields:

Answer 20

1) rainy years bring the risk of fungal diseases, affecting the yields
2) spring frost (if no protection is available)
3) having substantially less wine to sell in a particular year can be often extremely problematic for cash flow and consumer relations
4) yields that are higher than normal: the winery may not have the capacity for the increased volume of fruit and finding route to market/consumer for all the wine to have profit can be difficult
5) in some regions, winemakers may adapt by producing different styles of wine in cooler years (more sparkling wine or rosé compared to warmer or drier years

Question 21

The main measurable effect of climate change:

Answer 21

1) rise in temp
* consequent effect of greater evapotranspiration and therefore likelihood of water stress

2) changes in the geographical distribution of rainfall
3) greater weather variability and a greater frequence of extreme weather events

Question 22

Effect of rising temp on viticulture:

Answer 22

warmer temp:

1) vine cycle is faster
2) budburst occurs earlier in the spring and each stage of vine cycle becomes quicker

3) increased temp speed up the rate of sugar accumulation and reduction of acidity
* but do not quicken the ripening of most aroma compounds
* so no ensurance of exactly ripeness of aromas and tannins and the accumulation of colour

4) grapes may be picked with higher levels of sugar causing higher lvls of alc and lower acidity
* more rapid fall in acidity can give wines with higher pH lvls and this could be problematic in winemakig

Question 23

The effects of rising temp on aroma compounds is complex, but it is likely that as temp continue to rise, the grapes from certain vineyar regions may no longer exhibit the same aroma profiles as they do now:

Answer 23

1) black pepper is often a characteristic of syrah grown in moderate climates Northern Rhone
* with increasing temp it is likely that this hallmark aroma may no longer develop

2) some regions may become too warm for certain grape varieties (preferable to grow different, late ripening grape varieties to continue to provide balanced wines
3) can be benefical for other regions who where too cold to ripen grapes easily

Question 24

Drier conditions:

Answer 24

1) greater evapotr and altered rainfall patterns may benefit some regions that currently experience plentiful of rainfall in the growing season
* drier cond: reduce fungal disease
* mild water stress during ripening stage can be benefical

2) regions that already experience dry growing seasons (chance of extreme waterstress causing photosynthesis to stop and eventually the vines death)
3) some regions allready suffer (california, south africa) and these regions can be abbandoned in the next 50-100 years

Question 25

The increased frequency of extreme and erratic weather is problematic for all regions:

Answer 25

Storms, hurricanes, floods, unseasonal frosts and heatwaves

– all can reduce yields or grape quality

Question 26

Many wineries are changing to a sustainble way of growing:

Answer 26

1) renewable energy sources
* protecting natural ecosystems

2) to better prepare for climate changes: site selection, choice of planting material