Context: The permanent snow cover necessary for glacier formation is affected by factors such as the degree of slope on the land, amount of snowfall and the winds. Glaciers can be found in all latitudes except from 20° to 27° north and south of the equator where the presence of the descending limb of the Hadley circulation lowers precipitation so much that with high insolation snow lines reach above 6,500 m (21,330 ft). Between 19˚N and 19˚S, however, precipitation is higher and the mountains above 5,000 m (16,400 ft) usually have permanent snow.

Question: Do glaciers require permanent snow or only temporary coverage?
Answer: permanent snow cover

Question: Between which north latitudes are glaciers not found?
Answer: 20° to 27° north

Question: Between which latitudes to mountains tend to have permanent snow?
Answer: 19˚N and 19˚S

Question: Why do mountains between 19N and 19S tend to have snow?
Answer: precipitation is higher

Question: What affects the perminant ice layer needed for glaciers to form?
Answer: Unanswerable

Question: What can be found in every country from 20 degrees to 27 degess north and south of the equator?
Answer: Unanswerable

Question: At what lattitudes does the Hadley circulation rais percipitation?
Answer: Unanswerable

Question: At what latitudes does low percipitation lead to permanent snow?
Answer: Unanswerable