The Heights of the Reflecting Regions in the Troposphere

Observations upon the reflecting regions of the atmosphere show that in addition to the reflections from the E, F
l
, and F, regions, occasional reflections occur from heights of 50 and 25 (circa) kilometers. This has been called the D region. With a very short pulse (4 to 10 microseconds) and a rapid sweep upon the oscilloscope (18,000 inches per second), a reflecting region has been found within the troposphere. At the present time (summer, 1938) the region is about 1.8 kilometers high. This so-called C region changes its height with the change in weather. It may perhaps be influenced by magnetic storms, sunspots, and chromospheric eruptions.