Drop breakup dependence on altitude: evidence by MW disdrometer Pludix data

In real rain breakup is mainly due to collision between drops of different sizes and occurs when the Collisional Kinetic Energy is not absorbed by the colliding drops. In this work, we observe and measure the dependence on altitude of the occurrence of collisional breakup in real rain, and estimate the limit drop terminal velocities and size at the breakup. Data from Pludix were collected at three locations at different elevations: collisional breakup position in the power spectrum of Pludix increases towards higher frequencies with increasing altitude. Terminal velocities and sizes of the drops at breakup were determined consequently, with drop sizes resulting in 4.55 +- 0.35 mm, 4.02 +- 0.32 mm and 3.16 +- 0.3 mm for altitudes of 15, 950 and 3300 m a.s.l. respectively.