258 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
continent nearly twice the size of the United States, having an ice- 
covered surface 2 miles above sea level, lies at the Pole and is sur- 
rounded by the great southern ocean. This high central plateau, 
sheathed in darkness for 6 months each year, is a focal point for 
inward-circling storms and outward surges of cold air. The weather 
conditions in the Antarctic are nearly incredible; for example, wind 
velocities at Adelie Land have averaged 110 miles per hour for a day, 
more than 60 miles per hour for a month, and about 40 miles per hour 
for an entire year. The American IGY party now maintaining a 
vigil at the South Pole has already recorded temperatures below 
— 100° F. with 15- to 20-knot winds. 
As is well known, the testing of large atomic weapons produces 
considerable amounts of radioactive substances, some of which decay 
rather slowly. A large part of the radioactive material produced by 
atomic weapons tests is injected into upper strata of the air and can 
be used by meteorologists as a tracer of atmospheric movements, for 
example, to determine the rate at which the air at different levels is 
carried from the Northern to the Southern Hemisphere and vice 
versa, and the rate of mixing between the upper and the lower atmos- 
phere. An important IGY objective will be worldwide measurements 
of these artificially radioactive substances. 
GAINS AND LOSSES 
A slight excess or deficit in the input of solar energy over the output 
of infrared radiation from the earth may cause large changes in 
weather and, if long continued, in climate. At present we are unable 
to determine whether such differences between income and outgo exist. 
Here the earth satellite program shows great promise; one of the 
first satellites will carry relatively simple equipment for measuring 
the difference between the amounts of incoming and outgoing radia- 
tion at all points over its path. Later satellite experiments will 
include actual mapping of the earth’s cloud and snow cover, allowing 
accurate and continuous measurements of the amount of sunlight 
reflected from the earth, a quantity that can at present only be rather 
crudely estimated. 
A change in average air temperature represents, of course, a gain 
or loss of heat from the air, but it need not represent a gain or loss 
from the ocean-atmosphere-glacier system of the earth. On the other 
hand, an excess of heat could be stored for long periods on the earth 
without much change in the temperature of the lower air. There are 
two great mechanisms for this one: one is the melting of ice caps, the 
other is the heating of the deep waters of the ocean. The latter has by 
far the larger capacity. The energy required to melt all the ice in 
Antarctica is equivalent to about 214 years’ supply from the sun at the 
present rate of 175,000 calories per square centimeter each year. This 
