Week 5 - Global Climate Flashcards
What is weather?
The condition of the atmosphere at any given time and place.
What indicators make up the weather?
Barometric pressure, pressure tendency, surface air temperature, dew-point temperature, wind speed direction and characteristics, type and movement of clouds, visibility, precipitation.
What is barometric pressure?
Air pressure; controlled by altitude, temperature, rising or falling air.
What does pressure tendency mean?
Whether the pressure is rising or falling; if it’s rising it’s getting nicer, if it’s falling it’s getting yucky.
What is dewpoint temperature?
The temperature at which the air becomes saturated; 100% relative humidity.
What are the commonalities between the ITCZ and polar fronts?
Precipitation, low pressure, rising air
What is the difference between weather and climate?
Weather is day-to-day; climate is long-term big picture.
What is climate?
Climate is a synthesis of the changes in weather, from local to planetary, accounting for changes over time
Why is climate more than just average weather?
It’s also concerned with variability and extremes.
What controls climate?
Large scale circulation patterns, continentality, altitude, local geographic features, latitude.
How does latitude affect climate?
It controls seasonality, determines equatorial to polar regions, and is a major control in the amount of radiation received.
Are circulation patterns constant?
No, they shift with the seasons.
What happens to air temperature as altitude increases in the troposphere?
Air temp drops.
What happens to air temperature as altitude increases in the stratosphere?
Air temp rises.
What happens to air temperature as altitude increases in the mesosphere?
Air temp drops.
What happens to air temperature as altitude increases in the thermosphere?
Air temp rises.
Köppen Classification: Who and when?
Wladimir Köppen, a German climatologist, started the classification system in 1884 and continued working on it until his death in 1940.
Who assisted Köppen and from what year?
His student, Rudolph Geiger, from 1928 on.
What kind of classification system is the Köppen system?
Vegetation-based system. It’s an empirical system based on average monthly temperature, average monthly pp, and average yearly pp.
What are the five main climates in the Köppen-Geiger system?
Equatorial (A), arid (B), warm temperate (C), cool temperate snow (D), and polar (E).
What is the sixth classification used in the textbook, but not internationally accepted?
Highland climates.
Who added the highland climates to the Köppen-Geiger system?
Glenn Trewartha.
What is the bottom line for A climates?
Constant high temperatures; every month is above 18.
Af
Equatorial rainforest: No seasons. All 12 months have over 60mm of rain.
Where do Af climates occur?
Equatorial rainforests occur within 5-10 degrees of the equator.
What circulation pattern are Af climates dominated by?
Equatorial rainforests are dominated by the ITCZ.
What is the weather like in Af climates?
Lots of rain and clouds; 80-90% humidity.
What kind of clouds would you expect to find in Af climates in the afternoons?
Lots of cumulus clouds.
Am
Equatorial monsoon: Monsoons are seasonal changes in wind direction that bring moisture or dryness.
Where are Am climates most common?
Equatorial monsoons are most common in southern Asia and Africa.
As, Aw
Equatorial savanna; dry and wet seasons, but less pp than monsoon climates.
Where are As and Aw climates usually located?
Equatorial savannas are located on the outer edges of Equatorial-type climates; they are the transition to desert climates.
What’s the difference between As and Aw?
Aw - dry season is winter (most common); As - dry season is summer.
What does savanna mean?
From the Spanish “zavanna”, meaning “treeless plain”; however, there are some trees, just not many; precipitation supports mostly grass, rainy seasons are short.
How is a B climate classified?
Precipitation is less than potential evaporation.
What is potential evaporation?
Potential evapotranspiration is the amount of water that would be removed from the surface of a gridcell by evaporation and transpiration, if the amount of water already present in the cell were not a limiting factor.
BWh
Dry arid, low latitudes; dominated by sub-tropical high year round.
Describe the diurnal temperatures of BWh climates.
Wide diurnal temperature range due to lack of clouds.
BWk
Dry arid, mid-latitudes; usually caused by rain shadow or continentality.
What are the two main types of B climates?
Arid, deserts
Semiarid, steppe
What are steppe climates characterized by?
Grasslands
Where do steppe climates occur and why?
Steppe climates occur in mid-continental areas and are cause by mountains blocking moist air.
BSh
Semiarid low latitudes; sub-tropical high in part of the year, with seasonal ITCZ influence.
BSk
Semiarid mid-latitude; sub-tropical high in part of the year, with seasonal mid-latitude cyclones.
What are C climates?
Warm temperate; warmest month above 10, coldest month between -3 and 18
Csa, Csb
Mediterranean climates; Csa - interior; Csb - coastal
What circulation patterns dominate Csa and Csb climates?
Mediterranean climates are dominated by the sub-tropical high in spring, summer, and fall, and by mid-latitude cyclones in winter.
What are the seasons like in Csa and Csb climates?
Mediterranean climates have hot, dry summers and mild, wet winters.
What kind of vegetation do Csa and Csb climates produce?
Mediterranean climates produce vegetation that is able to resist dry periods.
Cfa
Humid subtropical
Where are Cfa climates usually found?
Humid subtropical climates are usually found inland or on the east coast of continents. (think southeastern USA)
What are season like in Cfa climates?
Humid subtropical climates have hot and muggy summers with frequent thunderstorms, and winters are mild with precipitation coming from mid-latitude cyclones.
Cfb and Cfc
Maritime temperate
Where are Cfb and Cfc climates located?
Poleward of Mediterranean climates.
What factors dominate Cfb and Cfc climates?
Mid-latitude cyclones and oceans.
What is the difference between Cfb and Cfc climates?
Cfb - mild winter; Cfc - cool winter (Iceland)
What are the D climates?
Temperate snow. Warmest month above 10, coldest month below -3
What factors cause D climates?
Temperate snow climates are caused by cold air from polar regions meeting hot air from the tropics
Dfa and Dwa
Mid-latitude systems along the Polar Front with Continental Polar (CP) air masses dominating in winter
What’s the difference between Dfa and Dwa?
Dfa is wet all year; Dwa has dry winters.
Dfb and Dwb
Humid continental mild summer
What’s the difference between Dfb and Dwb?
Dfb is wet all year; Dwb has dry winters.
f
Wet
w
Wet and dry.
Dfc, Dwc, Dfd, Dwd
Boreal and Tundra climates
Dfc, Dfd: similarities and differences?
Both wet all year, but Dfc is “cool summer” and Dfd is “cold winter”
Dwc, Dwd: similarities and differences?
Both have dry winters, but Dwc is “cool summer” and Dwd is “cold winter”
What are the major weather controls for Dfc, Dwc, Dfd, Dwd climates?
These boreal and tundra climates are mostly controlled by the Continental Polar (CP) and Arctic air masses, with occasional mid-latitude cyclones.
What are the E climates?
Polar! (Bloody cold!)
ET
Polar tundra.
What are the major controls in ET climates?
Polar tundra climates are mostly controlled by Arctic and Antarctic air masses, Polar vortex, and proximity to oceans
EF
Polar icecap
What are the major controls in EF climates?
Polar icecap climates are mostly controlled by Arctic and Antarctic ice masses, with Polar vortex and high elevations
How is the Köppen system affected by climate change?
It seems to be fairly resistant to climate change; it can bounce back from a weirdo year.
What does the Köppen system relate?
Climate and vegetation.
The Köppen system is readily explainable in terms of…
…air masses and global circulation.
What are some of the problems with the Köppen system?
- Can the climate of one place be described as the same as the climate of another?
- The relationship with biomes–not complex enough.
- Issue of scale.
What is a biome?
An area of the world that has a distinctive eco-system.
How can classification be political?
It can affect the way people view an area; e.g. Australia not wanting to be classified as a desert when they’re promoting tourism and immigration.
Who put the Köppen system in an Australian textbook and what happened?
Australian geographer Griffith Taylor put the Köppen system in his textbook in 1920. The textbook was banned in Australia and Taylor eventually left for Canada, where he opened the first geography department in a university.
Thornthwaite’s Classification
Based on annual water budgets; groups climates according to precipitation and evaporation.
Strahler’s system
Classified by processes that cause climates; relates climate to air masses.
All models are ____, but some are _____.
All models are wrong, but some are useful.
What advantage does the Köppen system have over the Thornthwaite and Strahler?
There’s more data available on precipitation amounts and temperature.
What is Kelowna’s Köppen classification?
Dfb
