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drought

(Encyclopedia)drought, abnormally long period of insufficient rainfall. Drought cannot be defined in terms of inches of rainfall or number of days without rain, since it is determined by such variable factors as th...

convection

(Encyclopedia)convection, mode of heat transfer in fluids (liquids and gases). Convection depends on the fact that, in general, fluids expand when heated and thus undergo a decrease in density (since a given volume...

hail, in meteorology

(Encyclopedia)hail, precipitation in the form of pellets composed of ice or of ice and snow, occurring at any time of the year, usually during the passage of a cold front or during a thunderstorm. Small hailstones ...

Gobi

(Encyclopedia)Gobi gōˈbē [key], Mandarin Yintai shamo, great stony desert of N central Asia, c.500,000 sq mi (1,295,000 sq km), extending c.1,000 mi (1,610 km) from east to west across SE Mongolia and N China fr...

tundra

(Encyclopedia)tundra tŭnˈdrə [key], treeless plains of N North America and N Eurasia, lying principally along the Arctic Circle, on the coasts and islands of the Arctic Ocean, and to the north of the coniferous ...

rainmaking

(Encyclopedia)rainmaking, production of rain by artificial means now generally disregarded, though it is probable that rainmaking hastens or increases rainfall from clouds suitable for natural rainfall. Interest in...

Ekimov, Alexei

(Encyclopedia)Alexei Ekimov, 1945– , b. Leningrad, USSR, Russian physicist, studied at Leningrad State University and Ioffe Institute of the Russian Academy of Scie...

Fischer, Hans

(Encyclopedia)Fischer, Hans, 1881–1945, German organic chemist, Ph.D. Univ. of Marburg, 1904; M.D. Univ. of Munich, 1908. Fischer was a professor at the Univ. of Innsbruck from 1916 to 1918 and at the Univ. of Vi...

I

(Encyclopedia)I, 9th letter of the alphabet. This vowel can be pronounced with a short vowel sound, as the ĭ in sit, or with a long vowel sound, like the ī in ride. The Greek correspondent is iota. J is a formal ...

Onsager, Lars

(Encyclopedia)Onsager, Lars, 1903–76, American physical chemist, b. Oslo, Ph.D. Yale, 1935. Onsager taught at Brown Univ. from 1928 to 1933 and was on the faculty at Yale from 1933 until his retirement in 1972. H...