Aerosol-Cloud Interaction measurements using Ground Based Remote Sensing Systems over urban coastal area

The interaction between aerosol particles and cloud plays an important role in studies of climate radiation. In particular, it is generally assumed that increases in aerosol loading results in higher concentration of cloud condensation nuclei which ultimately lead to increase cloud droplet number concentration and smaller cloud droplets effective radius. In this paper, direct ground based method is used to assess the Aerosol-Cloud Interaction at City College of New York (CCNY) based on the synergistic measurements by using microwave radiometer (MWR), multi filter rotating shadow band radiometer (MFRSR), light detection and ranging (LIDAR) systems, and Santa Barbara Discrete Ordinate Radiative Transfer (SBDART) model. The SBDART model is used to create the look-up-table for atmospheric transmittance which will then be used with MWR and MFRSR data. MFRSR provides transmittance, MWR gives liquid water path (LWP) and LIDAR offers aerosol extinction nearby clouds. The measured transmittance and LWP are function of cloud optical depth (COD) and cloud droplet effective radius (Reff). A method of iterative inversion algorithm is developed to obtain the COD and Reff. Then, aerosol extinction and cloud Reff are acquired to evaluate the correlation between them. Afterward, determining the effect of particle size in aerosol-cloud interaction by classification of aerosol type using Aerosol Robotic Network (AERONET) data will be presented. Finally, we assess MODIS and GOES satellite retrievals of COD & Reff against out ground based retrievals and illustrate the potential and limitations of satellite retrievals.