美洲榆上升羽流

Science. 1965 Apr 16;148(3668):392-3. doi: 10.1126/science.148.3668.392.

An unusual example of convection was recently seen above large elm trees shortly after sunset. The condensation of transpirational moisture in air that was cooler than that within the tree crowns is believed to account for the readily visible convective motion above the trees.

近日日落不久后，在大片榆树上方观察到一个不寻常的对流现象。据信，树冠内空气比周围空气温度高时，蒸腾作用产生的水汽在空气冷却时凝结，导致树木上方出现明显的对流运动。