Microphysical parameterizations based on Convair-580 observations collected during ISDAC

In-situ observations collected with instrument mounted on the Canadian National Research Council (NRC) Convair-580 aircraft during The Indirect and Semi-Direct Aerosol Campaign (ISDAC) which took place over Barrow, Alaska, for the April of 2008 were used in this study. The measurements of liquid water content (LWC), total water content (TWC), droplet, ice, and aerosol particle spectra, temperature (T), relative humidity (RH), shortwave and infrared broadband radiative fluxes (SWBR and IRBR, respectively), and vertical air velocity (wa), representing the entire ISDAC project, were used in the analysis. Measurements were utilized for the parameterizations of i) Nd versus Na and wa (Nd and Na are total droplet and aerosol number concentrations, respectively), ii) Ni versus T and RH (Ni: total ice crystal number concentration), iii) cloud fraction Cf versus TWC and Ls (averaging scale), and iv) a better understanding of Arctic cloud processes and aerosol-cloud-climate interactions. Preliminary results suggest that parameterizations are found to be comparable with earlier works but a large variability over various scales is present. It is concluded that interactions among the microphysics, dynamics, and aerosols over the various scales and variability should be considered in the microphysical parameterizations and in the study of Arctic clouds effect on climate.