Observation of aerosols and clouds in the western tropical Pacific using a two-wavelength polarization lidar on the research vessel Mirai

Observations of aerosols and clouds have been conducted in the Pacific with a ship-board Mie scattering lidar using the research vessel Mirai. The purpose of the observations is to obtain global distribution of aerosols and clouds over the Pacific Ocean for climatology and studies of radiative processes and ocean-atmosphere interaction. The data are used also in the study of data reduction and utilization methods for the space-borne lidars. The lidar for R/V Mirai is a two-wavelength Mie-scattering lidar (532 nm and 1064 nm) using a flashlamp pumped Nd:YAG laser. It has a depolarization receiver at 532 nm. We have performed observations in six cruises of R/V Mirai since 1999. Cloud distribution, cloud phase, vertical distribution of aerosol, wavelength dependence of aerosol backscatter, etc. have been analyzed. The parameters measured with the lidar, i.e. backscatter at two wavelengths and depolarization, are similar to space-borne lidars such as PICASSO and the Japanese "A-lidar". The results of the observations demonstrate the usefulness of a two-wavelength polarization lidar.