Troitskii, Semen Ivanovich

Born Jan. 28 (Feb. 9), 1889, in St. Petersburg; died Apr. 28,1934, in Leningrad. Soviet meteorologist.

Troitskii graduated from the University of St. Petersburg in 1913. In 1920 he joined the staff of the Main Physical Observatory (renamed the Main Geophysical Observatory in 1924).

Troitskii’s major works dealt with the use of aerological obser vational data for weather forecasting. He developed a theory of wind variation with height and carried out studies in aeroclima-tology and military meteorology.