I PART I. 1. Sierra Madre Occidental, Sierra Madre Oriental 7. - 28,000, false 8. This causes greater heating of the ground and results in an ascending air mass. As this air rises in the atmosphere, it cools as elevation increases. This causes water vapor to condense out of the air column and fall as precipitation.
Arid regions have a high coefficient of variation for annual precipitation.
In the latter example, this may result in population-wide death of individuals due to insufficient water being available. The seasonal amount of precipitation can, and does, vary in the North American deserts. Winter-occurring precipitation is more likely to be stored in the soil as winter temperatures are lower. Caliche is an accumulation of CaCO3. The accumulation occurs at the wetting depth for the region.