Assessing the performance of Ka-band millimeter-wavelength cloud radar
retrieval of microphysical parameters in central China Monsoon frontal
clouds
Abstract
This study investigates the microphysical properties of the Monsoon
frontal cloud (MFC), which were inhomogeneous and exhibited scale
differences based on observations and simulations. This research aims to
better understand MFC microphysical processes, which are crucial for
comprehending the precipitation mechanism during the summer of the
middle and lower reaches of the Yangtze river. The results show that the
Ka-band Precipitation Radar (KPR) measured reflectivity factor (dBZKPR)
agrees well with the observed reflectivity (dBZobs), with a correlation
coefficient of 0.78 and a mean bias of 2.45 dBZ along the aircraft
flight track, indicating the reliability of KPR for detecting and
retrieving cloud microphysical properties. Based on this, four
approaches were conducted to create the relationships between radar
reflectivity (Z) and microphysical parameters such as liquid water
content (LWC) and effective diameter (De) which were then validated.
Differential precipitation and non-precipitation clouds proved effective
in predicting LWC using dBZKPR, while De required the further division
of LWC into seven bins at 100.5 g m-3 intervals. The empirical formulas
used in this study produced results closest to observation data compared
to previous studies. Detailed criteria for using these formulas were
quantified, including differentiating grounded echoes and the size of
the retrieved LWC values. This study sheds light on the microphysical
properties of the MFC and provides insights into the precipitation
mechanism of the middle and lower reaches of the Yangtze river during
the summer.