Answer to Question 1
Answer: Highland climates are unique among those in the Koeppen system because their distribution is not governed by geographic location but rather by topography. These climates are found in large mountain or plateau areas. In high mountains large changes in the mean temperature can occur over short distances, simply as a function of elevation. The temperature situation becomes more complicated when one considers that changes in slope angle and aspect over short distances influence the intensity of solar radiation received.
Answer to Question 2
Answer: Subarctic climates occupy the northernmost extent of the severe midlatitude regions, with more than half of the area of Alaska and Canada having this type of climate. Summer temperatures are somewhat lower than those of the adjacent humid continental regions, but the major difference occurs in winter, when mean monthly temperatures can be extremely low. Tundra climates are named for the associated vegetation type that consists primarily of low-growing mosses, lichens, and flowering plants, with few woody shrubs and trees. Tundra climates have severe winters in which the Sun rises only briefly each day and never gets very high above the horizon. Under these conditions, radiational cooling at the surface leads to low temperatures and strong stabilityboth factors that inhibit precipitation. Thus, low winter precipitation is the rule. Surprisingly, perhaps, the winters in the tundra regions are often less severe than those of the adjacent and lower-latitude subarctic climates. This is because the tundra regions of North America, Greenland, and Asia are located nearer to major water bodies and thus have a lesser degree of continentality.
An example of a homeostatically controlled variable: blood levels of glucose in a human.
Controlled Experiments Manipulate a Variable
Example from Highland Papua New Guinea
Variable Gases of the Atmosphere
The Dry Climates (B)
Variable penetrance of mitochondrial mutations