Significant variability of microphysical characteristics existed in the “21•7” Henan extremely heavy rainfall event

This study is led by Dr. Gang Chen (Nanjing Joint Institute for Atmospheric Sciences) and Prof. Kun Zhao (Key Laboratory for Mesoscale Severe Weather/MOE and School of Atmospheric Science, Nanjing University). Based on the combined observations of a dense network of disdrometers and two polarimetric radars, the international team of scientists presented evidence of the substantial microphysical variability in the “21·7” Henan EHR event.

The team found the mean sizes and number concentrations of raindrops were widely distributed when analyzing the datasets of 50 disdrometers. All the datasets were objectively clustered into five groups by a K-means clustering algorithm. Distinctive rain rates, Dm –log10(Nw) , and rainfall contributions of raindrop sizes were obtained among the five groups, indicating the variability of precipitation microphysics in the “21·7” Henan EHR event. Microphysical structures of convection were provided by the supporting polarimetric radar observations, distinctions of convection depths, ice hydrometeors distributions, and mean raindrop size and number concentration in warm cloud layers existed in different rainfall groups. Deeper (shallower) convection was also found in the plain (mountain) regions, causing larger (smaller) raindrop sizes at surface.

These new exciting results add to the growing evidence that substantial microphysical variability can exist in individual precipitation event, and lay the foundation for future efforts to improve quantitative precipitation estimation and forecast performances.

See the article:

Chen G, Zhao K, Lu Y, Zheng Y, Xue M, Tan Z M, Xu X, Huang H, Chen H, Xu F, Yang J, Zhang S, Fan X. 2022. Variability of microphysical characteristics in the “21.7” Henan extremely heavy rainfall event. Science China Earth Sciences, https://doi.org/10.1007/s11430-022-9972-9

---

---