Observational study on relationship between aerosol and CCN spectra, and effect of observation-constrained CCN on WRF-simulated precipitation

The objective of this study is twofold. First, we analyze aerosol and CCN observations collected on the ground and in the air during 2005-2007 in North China to empirically examine the spatial and temporal distributions of aerosol and CCN, and the relationship between aerosol properties, activation ratio defined as the ratio of CCN to aerosol concentration, and CCN spectra. Then the results including vertical distribution and the activation spectrum of CCN are used to constrain the WRF microphysics scheme and to simulate a precipitation system. The aerosol effect on precipitation is investigated by comparing the simulation with the original scheme and precipitation measurements.