Interrelation of aerosols, water vapor and clouds on a global scale Original Research Article

Each retrieval algorithm for atmospheric aerosols, clouds and water vapor from ADEOS/POLDER data is described. A POLDER sensor, mounted on the Earth observation satellite ADEOS in 1996, is a unique sensor which can gather multi-directional (up to 14) polarization measurements of one target. Atmospheric aerosol properties as optical thickness and Ångström exponent are derived from the POLDER polarization data at wavelengths of 0.670 and 0.865 μm. The polarization data at 0.865 μm. is also available for cloud retrieval. Two channels in the near infrared wavelengths are used to estimate the total column water vapor content. The first channel is in the water vapor absorption band of 0.910 μm. and the second is in the gas absorption-free band of 0.865 pin. In practice, a ratio of each reflectance for these two channels is used in this study. Then the obtained global maps of aerosol properties, cloud microphysics and water vapor content are compared with one another. It is shown that column number density of aerosols has a negative correlation with the effective radius of cloud particles and proportionally correlates with the optical thickness and the column number density of cloud particles. These results confirm the indirect effect of aerosols, namely aerosols play sufficient role as cloud condensation nuclei (CCN).