Michael R. McGowen, Morgan L. McCarthy, Felix G. Marx, Natacha Aguilar, Merel L. Dalebout, Sascha Dreyer, Oscar E. Gaggiotti, Sabine S. Hansen, Anton van
Favour,Biplane to Moniplane,Aircraft Development 1919-30, ISBN 0851778747 JamesR. Hansen,The Bird Is on the Wing: Aerodynamics and the Progress of the American
1974 年由James E. Hansen和Larry Travis提出,定义为液滴尺寸分布的三阶矩与二阶矩之比,用于反演遥感数据。 从物理的角度来看,它是云滴粒子的面积加权半径。在数学上,计算公式为 r e = ∫ 0 ∞ π ⋅ r 3 ⋅ n ( r ) d r ∫ 0 ∞ π ⋅ r 2 ⋅ n