Improving the Representation of Raindrop Size Distributions Using the
In-situ Microphysics Observations Collected in Hurricanes
Raindrop Size Distributions (RSDs) samples from 17 flight missions
though 6 hurricanes collected by Precipitation Imaging Probe (PIP)
during National Oceanic and Atmospheric Administration’s hurricane field
program in 2020 are used to study gamma fits of the RSDs in hurricanes.
The method of moment (MM) is adopted for solving for the three
parameters in gamma distribution. The results show that the usage of
lower (higher) moments produces large biases for integral rain variables
(IRV) of higher (lower) moments. These biases can be alleviated by
extracting the best fits from five groups that use increasing higher
orders of moments for MM. An intercept (N0)— slope (λ) relation
identified from the fitted gamma distributions captures 92% of the
variance of the data, where the majority of remaining 8% can be further
captured by including the impact of liquid water content (LWC), as shown
in the results from a random forest regression model.