Page 166 - Handbook of Gold Exploration and Evaluation

144 Handbook of gold exploration and evaluation

3.5 Temperature structure of the atmosphere (after Strahler and Strahler,
1992).

four major environmental layers: `troposphere', `stratosphere', `mesosphere',
and `thermosphere', based upon zones of temperature change. The atmopshere is
densest at sea level, thinning rapidly upward (Fig. 3.5). Climate is a generalised
term that describes prevailing conditions in a given region, e.g. temperature,
humidity, cloud cover and height, wind speed and direction, and precipitation.
These are also functions of weather but whereas weather, as a small component
of climate, refers to meteorological conditions at the time of reading, climate is
the average of meteorological conditions over long periods of time and takes
account of extremes, averages and frequencies of individual readings.

3.2.1 Sun±Earth space energy relationship

Solar radiation
Atmospheric temperature is a function of the modification of solar radiant energy
by air, clouds, land, sea and other water surfaces. Solar radiation is discharged
from the Sun in the form of electro-magnetic radiation divided roughly into:

· ultraviolet and shorter wavelengths (7.8%)
· visible light (47.3%)
· infra-red light (44.9%).