Discussion 5

Global Climate Systems

I. Introduction:

Climate is what you expect. Weather is what you get.........

Generally speaking, climate is the average weather of a region.

II. Two Main Climate Indicators: The annual patterns of (1)temperature and (2) precipitation. This, in turn, is primarily determined by:

III. Main factors affecting temp and precip – Review!

A. Latitude: …affects day length and sun angle (which generally determine temp)

B. Proximity to oceans: …determines whether you’re likely to receive Maritime or Continental air masses

C. Prevailing winds: … determines where your weather (storms, air masses, etc) come from?

D. Altitude: High altitudes will be colder due to the Normal Lapse Rate.

IV. Global Precipitation Map: ( isohyets are lines of equal precip)

A. Recall the positions of:

1. Intertropical Convergence Zone (equatorial low pressure trough): high convectional rainfall

2. Hadley Cell

3. Subtropcial High Pressures: 30(North and South Latitude; generally clear weather

4. Trade winds

5. Westerlies: (the track of polar front cyclones; warm and cold fronts)

B. Review the following global precip. patterns

1. Where is the highest precipitation and why? Along the equator… ITCZ causes high convectional precipitation.

2. Why is there high precipitation in mountains? Orographic lifitng causes high precipitation.

3. Why is there low precipitation along the tropics of Cancer and Capricorn? Sub-tropical High Pressure influence suppresses cloud formation.

4. Why does the Andes' rainshadow desert switch from east slope to west slope? Because the prevailing winds are from the East at around 5-25° South Latitude and from the West at around 30-50° South Latitude.

5. Why are the interiors of N.America and Asia so dry? They are far from maritime air masses.

6. Why are many midlatitude east coasts wetter than midlatitude west coasts? East coasts receive wetter tropical air masses, while west coasts receive drier polar air masses

V. Climagraph: A graph showing both annual patterns of average monthly temperature and precipitation.

VI. Climate Types

A. Tropical Climates (warm season rains!!!)

1. Tropical Rainforest:

· What?: Warm, humid, and rainy in virtually all months

· Why?: ITCZ brings rain in all months (ALL ITCZ – ALL the time!)

· Where?: Located at or near Equator

2. Tropical Monsoon:

· What?: Extreme warm season rains, cool season drought

· Why?: ITCZ rains are summer only; winter is high pressure w/ no rain

· Where?: Generally north and south of Trop Rainforest

3. Tropical Savanna:

· Similar to Tropical Monsoon (above), but with much less rain.

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B. Dry Climates (desert is drier than a steppe; both are dry!)

1. Low Latitude Hot Steppe

2. Low-Latitude Hot Desert

3. Mid-Latitude Cold Desert

4. Mid-Latitude Cold Steppe

· What?: DRY, can be hot or cold

· Why?:

1. Constant sub-tropical high pressure and/or

2. Leeward sides of mountains (rainshadow) and/or

3. Continental locations (FAR from an ocean)

· Where?: See map for details

C. Mesothermal Climates (means "middle temperature" or mild)

1. Mediterranean:

· What?: Warm dry summer, cool rainy winter

· Why?: Sub-trop high pres. in summer, polar front cyclones in winter

· Where?: Midlatitude west coasts (near cold ocean currents)

2. Humid Subtropical: (not pictured below)

· What?: Warm or cool, almost always humid and rainy

· Why?: Strong flows of mT air in summer, polar front cyclones in winter

· Where?: Midlatitude east coast (near warm ocean currents)

D. Other Climates (be able to recognize polar, southern hemisphere, and other obvious climate patterns in a climagraph)

See sample questions on next page>>>>>>>>

Sample Questions: Questions similar to these will be on your exam. As you study you should anticipate how I might use these questions to create new questions on the same concepts.

1	During which month will Darwin, Australia most likely experience monsoon conditions? (Hint: Darwin is at approx. 12°S Latitude) A. July B. September C. March D. May E. January
2	The Patagonia desert is found around 35-45º South Latitude at the base of the Andes Mountains. Which side of these mountains is it likely found on? A. east side B. west side C. windward side D. south side E. north side
3	What are the three basic causes of deserts and dry conditions?
4	Which location has a Mediterranean climate? (map provided at time of exam)
5	Which location is under the influence of sub-tropical high pressure during summer months only? (map provided at time of exam)
6	Which location is under constant influence of the ITCZ? (map provided at time of exam)
7	See attached climagraphs. Which location is under the influence of subtropical high pressure for most of the year?
8	See attached climagraphs. Which climagraph shows a Southern Hemisphere monsoon pattern?
9	See attached climagraphs. Which climagraph illustrates conditions at the South Pole?
10	See attached climagraphs. Which climagraph shows a Southern Hemisphere Mediterranean climate?

GOOD NEWS!!! The practice questions above - plus many, many more – can be found in the online practice quizzes discussed in your syllabus and in class. You can take each quiz multiple times, and each time you will get some new questions. Once submitted, the quizzes are graded automatically, with the correct answers provided immediately. This is a great way to prepare for the exams!!!

Tropical Monsoon

Tropical Savanna

Tropical Rainforest

Fig. 7-8 page 233, 6th ed

Fig. 7-5 page 224, 7th ed

Fig. 7-5 page 226, 8th ed

Fig. 7-7 page 232, 6th ed

Fig. 7-4 page 223, 7th ed�Fig. 7-4 page 225, 8th ed

Fig. 7-6 page 232, 6th ed

Fig. 7-3 page 222, 7th ed�Fig. 7-3 page 224, 8th ed

CRITICAL

Fig. 7-24 page 250, 6th ed

Fig. 7-20 page 237, 7th ed�Fig. 7-19 page 240, 8th ed

Fig. 7-23 page 249, 6th ed

Fig. 7-19 page 237, 7th ed

Fig. 7-18 page 239, 8th ed

Low-Latitude Hot Desert

Mid-Latitude Cold Desert

Mediterranean Hot Summer

Mediterranean Cool Summer

Fig. 7-14b page 239, 6th ed

Not in 7th ed�Not in 8th ed

Fig. 7-14a page 239, 6th ed

Fig. 7-10 page 229, 7th ed�Fig. 7-10 page 230, 8th ed

Practice Map for Locating Climate Zones