Fluctuations and Latitude Effect of Cosmic Rays at High Altitudes and Latitudes

Using a newly developed ionization chamber, which transmits its information by radio, simultaneous balloon flights were made from widely separated stations in the summer of 1951. Bismarck, North Dakota (geomagnetic latitude, ${\lambda }_m$, 56°N) was used as a base station. Four flights were made from shipboard going north from Boston and five were made from Thule, Greenland (${\lambda }_m=88\mathrm{}°$N), simultaneous with those at Bismarck. In all, 28 successful flights were made by the two expeditions. In seeking to determine the geomagnetic effects on the low energy primaries, considerable information was gathered on the radiation that fluctuates from day to day. The following are the chief experimental findings together with some of the conclusions that may be drawn.