Page 392 - Fundamentals of Air Pollution 3E

Fig. 21-1. World network of radiosonde stations. Ten stations, one in the Atlantic and nine in the Pacific, are not shown.
Each dot represents a station at which an upper-air sounding is made each day at 0000 hr GMT, at 1200 hr GMT, or both.
Source: the Secretary-General, World Meteorological Organization, Geneva.