The logarithm of a ratio of two values for this quantity over the logarithm of a ratio of corresponding altitudes equals the Hellmann constant. Roughness length appears in an equation modeling the “log profile” of this quantity. This quantity deviates from ideal “geostrophic” values and increases logarithmically with altitude (0[1])due to the planetary boundary (0[1])layer. (0[1])This quantity is calculated (0[1])with pressure measurements from (*) Pitot (“PEE-toh”) tubes. (10[2]0[4])Sea conditions (10[1]0[1])can be used to infer this quantity (10[1])with the Beaufort scale. (10[6]0[2])A (10[1])four-cup (10[2])design (10[1])is used to measure (10[1])this quantity (10[3])with an anemometer. (10[2])Categories (10[1])of tornadoes are distinguished in the Fujita (10[1])scale (10[1])by, for 10 points, (10[1])what atmospheric quantity that can (10[1])be measured in knots? (10[2]0[1])■END■ (10[7])