Atmospheric aerosol distributions and cloud properties using multiwavelength Raman lidar measurements
Document ID: 246
Verghese, Sachin John1
Philbrick, C. Russell2
1 Ansys Inc., Canonsburg, PA. U.S.A.
2 North Carolina State University, Department of Physics, Raleigh, NC, U.S.A.
Abstract
Improved measurements of atmospheric aerosol properties are essential for a better understanding of the roles of aerosols in processes that modify the Earth’s radiation budget. Raman lidars have been used for a number of years to measure the profiles of N2, O2, H2O, O3, optical extinction, and temperature using the vibrational and rotational Raman scatter signals. Measurements obtained during several field campaigns have provided datasets for investigating aerosol and cloud properties. The extinction profiles at several wavelengths are used to observe changes in the aerosol sizes in the accumulation mode range. Models based on Mie scattering calculations are compared with measurements of multi-wavelength extinction to investigate changes in the size of particles as clouds develop and dissipate. We demonstrate the capability of this technique using the multi-wavelength extinction ratios to observe changes in particle sizes in the range 50 nm to 1.0 μm. An example is used to demonstrate changes in the size of cloud particles observed during formation and dissipation stages of cloud evolution using multi-wavelength aerosol extinction profiles. We also examine the relationships that exist as particle sizes increase or decrease by comparing multi-wavelength extinction coefficients with changes in relative humidity.
Keywords: aerosol properties, cloud properties, Raman lidar, optical extinction
| Citation: | "Atmospheric aerosol distributions and cloud properties using multiwavelength Raman lidar measurements", Verghese, S. J., C. R. Philbrick, Atmosphere, Vol. 3, MDPI (Multidisciplinary Digital Publishing Institute), Basel, Switzerland, 2012, pp. 1 - 17, DOI: 10.3390/atmos30x000x, ISSN: 2073-4433 |