Advantages of G-Band Radar in Multi-Frequency, Liquid Phase Microphysical Retrievals

Radar based microphysical retrievals of cloud and droplet properties are vital for informing model parameterisations of clouds and precipitation. But these retrievals often do not capture the details of small droplets in light rain or drizzle. A state-of-the-art G-band radar is used here to improve retrievals in two cases studies with light rain or drizzle. Improvements were seen, as compared to W-band radar, in the retrieval of vertical wind speed, due to the location of Mie minima at smaller droplet sizes with the G-band radar. This, in turn, had an impact on the retrieval of the drop size distribution, allowing for improved accuracy in the retrieval of the characteristic drop diameter and improvements in the retrieval of the smallest droplet sizes. The increased attenuation received at G-band also allowed for better retrievals of differential attenuation (and therefore liquid water content) when paired with W-band or Ka-band as compared to the W-band and Ka- band pairing alone. This is particularly noticeable in periods of light rain where the W-band and Ka-band radars receive negligible attenuation while the attenuation at G-band is much greater, allowing for the more accurate measuring of differential attenuation.