Estimating drizzle drop size and precipitation rate using two-colour lidar measurements

Estimating drizzle drop size and precipitation rate using two-colour lidar measurements

A method to estimate the size and liquid water content of drizzle drops using lidar measurements at two wavelengths is described. The method exploits the differential absorption of infrared light by liquid water at 905 nm and 1.5 μm, which leads to a different backscatter cross section for water drops larger than ≈50 μm. The ratio of backscatter measured from drizzle samples below cloud base at...

A method for estimating rain rate and drop size distribution from polarimetric radar measurements

Polarimetric radar measurements are sensitive to the size, shape and orientation of raindrops and provide information about drop size distribution (DSD), canting angle distribution and rain rate. In this paper, we propose and demonstrate a method for retrieving DSD parameters for calculating rain rate and the characteristic particle size. The DSD is assumed to be a Gamma distribution and the go...

Space-borne Measurements of Changes in Cloud Optical Thickness and Cloud Drop Size Associated with Precipitation

The cloud feedback problem is one of the largest uncertainties in climate studies because cloud formation and dissipation are complicated processes. Clouds have mutual relations to aerosols and precipitation. Increases in aerosol concentrations result in a decreased drop size and modify the cloud radiative forcing. Decreased drop size may also suppress precipitation. Precipitation is generated ...

Drop size ambiguities in the retrieval of precipitation profiles from dual-frequency radar measurements

The threat of flooding from landfalling tropical cyclones is a function of the local variation in rain rate and rain accumulation. To date, these have been inferred from single-frequency radar reflec-tivity measurements. However, the Tropical Rainfall Measuring Mission experience has confirmed that one of the main difficulties in retrieving rain profiles using a single-frequency radar is the un...

Testing Lidar-Radar Derived Drop Sizes Against In Situ Measurements