Measurements and Discrimination of Aerosol and Cloud Layers Using a Multi-Wavelength Elastic- Raman Lidar

Aerosols and clouds play an important role in air-quality, weather and climate relevant studies. The

correct discrimination of aerosol and cloud and their subtype classification are critical in the retrieval of

remote sensing measurements from ground and space. In this presentation, we provide visual vertically

resolved measurements of aloft aerosol and cloud layers from a multi-wavelength Elastic-Raman lidar

during the summer of 2016 in New York City. Then, we implement an algorithm based on one full day

(July 28, 2016) discriminating aerosol and cloud based on spectral dependence or attenuated color-ratio of

aerosols and clouds. The color-ratios at the three-wavelength pairs and the different thresholds are

examined for improving the detection sensitivity or capability. Furthermore, a wavelet-analysis technique

with different scales parameter is refined to estimate the heights of aerosol and clouds. The analysis of the

July 28, 2016 data showed that optically thin clouds can be misclassified as aerosols. Modifications will

be made to the algorithm, specifically the threshold values used for the color-ratio analysis, to reduce

misclassifications.