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Flashcards in Climate Deck (37):

What are the minimum hours of sun a vine needs during the growing season?

1500 hours minimum


Do red grapes or white grapes generally need more sun to reach full ripeness?

Red grapes generally need more sun to reach full ripeness.


What is the minimum amount of rain per year a vine needs to survive and grow?

700mm (27.6 inches) rainfall per year


What 2 climate features are most influential on grapevines?

  1. Rainfall
  2. Temperature


What effect do bodies of water (oceans, lakes, rivers) have on climate?

Bodies of water help moderate temperatures.


Define cool climate.

A region with a cool climate will have an average growing season temperature of 14.5°C - 16.5°C (58ºF - 62ºF).


Define moderate climate.

A region with a moderate climate will have an average growing season temperature of 16.5°C - 18.5°C (62º - 65ºF).


Define warm climate.

A region with a warm climate will have an average growing season temperature of 18.5°C - 21°C (65º - 70ºF).


Define hot climate.

A region with a hot climate will have an average growing season temperature greater than 21°C (70ºF).


Describe Maritime climate.

Maritime climates are those that are influenced by large bodies of water and have warm summers and mild winters with rain falling year-round.

Bordeaux and Rías Baixas are examples of Maritime climates.


Describe Mediterranean climate.

Mediterranean climates have very warm, dry summers and cool, rainy winters.

Southern Rhône and McLaren Vale are examples of Mediterranean climates.


Describe Continental climate.

A Continental climate is one that has climate extremes: hot summers and cold winters.  They tend to be interior regions.

Northern Rhône and Ribera del Duero are examples of Continental climates.


What is the effect of the Gulf Stream on Europe?

The Gulf Stream adds a warming effect to the climates of northern and western Europe.

Fun fact: Galway, Ireland has palm trees thanks to the Gulf Stream.


Name the cold air current that affects South Africa.

Benguela Current


Name the cold air current that affects Chile.

Humboldt Current


Name the cold air current that affects California.

California Current


Name the southwesterly wind that cools Swan District in Australia.

Fremantle Doctor


Name the southeasterly wind that cools down Cape Town, South Africa.

Cape Doctor

The Cape Doctor blows up through False Bay from spring (August/September) through late summer (May/April) clearing away smog, etc. and replacing it with fresh sea air.


Describe the 'Table cloth' phenomenon in South Africa.

The 'Table cloth' in South Africa is air that blows up from False Bay and picks up warm moisture from the Bay, then runs up against the eastern side of Table Mountain creating clouds, and then rainfall, on the eastern side of Table Mountain.


Why do rivers mitigate frost damage?

Because rivers' air currents keep air moving - instead of settling - in vineyards.


What encourages Noble Rot (Botrytis)?

When early morning mists or fog from nearby bodies of water create humid land conditions which are then followed by warm, dry, and sunny afternoons.  

The humidity allows the Botrytis spores to attack the grapes; the sun-filled afternoons allow the spores to germinate.

Sauternes and Tokaji are examples where this phenomenon happens.


What is the rain shadow effect?

As weather systems move from west to east, foul weather is stopped by or trapped in mountains thereby leaving the eastern side of mountains with brilliant sunshine and nice weather.  The western side gets all the rain and clouds.

The Vosges, Cascades, and Andes Mountains are all examples of mountain ranges that create rain shadows.


Because rain shadows provide warm, sunny weather for the eastern side of mountains, what does that allow vignerons in rain shadows to do?

Vignerons can plant vineyards at higher altitudes on the eastern side to help the vines find cool nights, down drafts, and drainage.

Salta, Argentina and Orange, Australia are examples of appellations planted at higher altitude on the eastern slopes of mountain ranges.


What is a diurnal shift?

A diurnal shift is the change in temperature from daytime to nighttime.

The larger the diurnal shift (lower lows, higher highs) the better it is for the vine; warm daytime temps help develop sugar and phenolic ripeness whereas cool nighttime temps help preserve acidity and freshness.


What does continentality mean?

Continentality is the difference of temperature between the coldest month and the hottest month in a region.

Regions with high continentality, such as landlocked regions like Ribera del Duero, have a big variation of temperature between their coldest winter months and their hottest summer months.


What is the Heat Summation Index and where is it generally used?

The Heat Summation Index, also known as the Winkler Index, is used predominantly in New World countries to classify their climates.

The Heat Summation Index is classified by Regions I, II, III, IV, and V.

This Index is based on the assumption that vines are not active below 50ºF.  Each day between April 1 - October 31 (the growing season) is considered a "degree day."  Each degree day has a value which is determined by taking the average daily temperature for that day and subtracting 50 from it (e.g. 90º as an average, subtract 50º from it, giving that degree day a value of 40º).  When each degree day's value is added up between April 1- Oct 31, that sum determines what Region class that appellation is in.

Region I - 1500 - 2500 degree days (e.g. Champagne)

Region II - 2500 - 3000 degree days (e.g. Bordeaux)

Region III - 3000 - 3500 degree days (e.g. Rioja)

Region IV - 3500 - 4000 degree days (e.g. Napa Valley)

Region V - 4000+ degree days (e.g. Jerez)


How do Europeans classify their climates?

By Zones.

Zone A - coldest, e.g. the UK and Mosel

Zone B - e.g. Alsace, Slovenia

Zone C1 - e.g. Bordeaux, Burgundy, northern Italy

Zone C2 - e.g. Languedoc-Roussillon, central Italy

Zone C3a - e.g. northern Greece, Bulgaria

Zone C3b - hottest, e.g. southern Italy, Corsica


What are the diferences between:

  • Macroclimate
  • Mesoclimate
  • Microclimate


  • refers to the climate of a region, e.g. Burgundy;


  • refers to the climate of a village or a cluster of vineyards on a slope, e.g. the village of Puligny-Montrachet or the Grand Cru slope of Chablis;


  • refers to the climate of a very small area, such as a single vineyard or even the climate within the vines and around the canopy, e.g. vines at the top of the hill vs. the bottom of the hill in Clos Saint-Jacques (Gevrey-Chambertin) or the terraces in Valtellina, Lombardy.


How can a viticulturist tweak a vine's microclimate?

Through canopy management.  

The viticulturist can either allow the canopy to become lush -- which allows for more shade and cooling effect in the fruit zone -- or by pulling shoots off the vine to allow the grapes more sun exposure.


Generally speaking, in what regions will one find the most vintage variation?

In regions that are *just* suitable for growing vines as they are susceptible to changes in weather.  These just-suitable growing areas do not have a consistent or stable climate year-in and year-out.

Regions such as Bordeaux, Chablis, and Mosel can have more vintage variation because they can be affected by heavy rainfall at harvest, springtime frost, or summertime hail.

Regions such as Mendoza, McLaren Vale, and Central California will not have as much vintage variation because they have much more stable, predictable climates.


What does 'earthing up' mean?

'Earthing up' is when a vicitulturist mounds up additional soil around the base of the vine's trunk to help retain warmth over winter.

This is done to young vines in particular to protect against deep winter freezes.


What are the 4 important protections a viticulturist can take against frost?

  1. Smudge pots which create a literal blanket of smoke to help keep the vineyard warm(er);
  2. Fans, wind machines, or helicopters to circulate warm air above the ground with the cold air that settled around the vines;
  3. Aspersion, when water is sprayed onto a vineyard so that a thin later of ice is formed on the vine which helps insulate it;
  4. Conscientious vineyard design to avoid depressions; can also high-train vines.


What happens to a vine when it suffers from drought conditions?

A vine will shut down if it doesn't have enough water to produce photosynthesis.

  • leaves will stop all work
  • sugars won't be produced
  • grapes won't ripen properly


What is the difference between altitude and aspect?

Altitude is height above sea level, e.g. the Uco Valley in Mendoza, Argentina is 3000 - 3900 feet above sea level (a.s.l.)

Apsect indicates the direction which a slope faces, e.g. top sites in Burgundy have a southeasterly aspect which provides them more gentle morning sun and protects them from hot afternoon sun.


Describe lake effect.

As large bodies of water take a long time to warm up and cool down, 'lake effect' has a moderating aspect on climate.

During the autumn, a lake that has warmed up over the summer releases its accumulated warmth to the surrounding land thereby extending the growing season for grapes and keeping away early frosts.

During the spring and early summer, the lake is still cold from winter.  As the land around a lake heats up, warm air rises from the earth which sucks in the cool air coming off the lake, creating on-shore breezes.




Why is rain at harvest not a good thing?

Rain close to harvest can result in:

  • Dilution of flavors in grapes
  • Dilution of sugars in grapes
  • Create rot

This is why winemakers will have to decide to pick either before a big rain or wait several days after the rain for the vines to metabolize the rainwater.


What is the damage that hail can do to a vineyard?

Hail can:

  • Perforate leaves rendering them unable to photosynthesize;
  • Damage bud wood, creating open wounds which invite bacteria;
  • Knock clusters or grapes off the vine, decreasing yields.