Atmospheric aerosol distribution and cloud properties using Raman lidar
Document ID: 184
Verghese, Sachin John
Philbrick, C. Russell
The Pennsylvania State University, Department of Electrical Engineering, University Park, PA, U.S.A.
Abstract
Atmospheric aerosol measurements are essential to better understand their role as a feedback process in modifying the Earth’s radiation budget as well as their influence on human health. The PSU Raman lidars have been used for a number of years, in different locations, to measure the profiles of molecular nitrogen, molecular oxygen, water vapor and the rotational Raman scatter (the mixture of all molecular species) at both visible and ultraviolet wavelengths, and also ozone in the ultraviolet. An aerosol extinction profile, which provides an excellent method to describe aerosol distribution, is then obtained from the incremental extinction based on the difference in the slope of the measured profiles from the major molecular components known vertical gradient. The datasets collected by the PSU Raman lidars, during different campaigns, allow us to infer atmospheric aerosol size variations over different altitude regions by using extinction variations as a function of wavelength to describe the changes in the size distribution of aerosols. This variation in the extinction profiles at different wavelengths can also be used together with the water vapor profiles to study the formation, growth and dissipation of cloud structures. The change in the size of the cloud particles during the different stages can also be observed in the multi-wavelength aerosol extinction. The growth of a cloud, as particles absorb water, is usually associated with a decrease in the water vapor concentration around the cloud. Similarly, a dissipating cloud is characterized by an increase in the water vapor concentration surrounding the region.
| Citation: | "Atmospheric aerosol distribution and cloud properties using Raman lidar", Verghese, S. J., C. R. Philbrick, unknown publisher, 2005, pp. 1 - 5 |