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Obtaining Accurate Aerosol Extinction and Backscatter Coefficients Using Ceilometers

ORAL

Abstract

How different types of aerosols in our atmosphere explicitly affect quality and visibility on any given day is not quite clear. The aerosol extinction coefficient - $\alpha $ - and backscatter coefficient - $\beta $ -- can indicate these characteristics. Ceilometers can measure the backscatter power due to aerosols, but when diffuse sunlight reaches the ceilometer's sensors, it can alter the retrieval signal. Using this data leads to less accurate calculations. To obtain accurate calculations, a smoothing function was created to alleviate background noise. The results of the function were compared to Savitzky-Golay filtering of the backscatter power; the respective method's gradients showed the generated function produced more distinct atmospheric layers. With this new smoothing method, it is hypothesized that more accurate values for $\beta $ and $\alpha $ can be evaluated with the LIDAR Equation. The proposed process uses ceilometer data to calculate $\beta $ and the LIDAR ratio, which together can yield $\alpha $. The accuracy of the calculated $\alpha $, and thus the effectiveness of the smoothing function, can be tested by comparing the Aerosol Optical Depth (AOD), derived from $\alpha $, to sun photometer data AOD measurements.

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Authors

  • Sarah Bowers

    University of Maryland, Baltimore County

  • Abdul Qadeer Rehan

    University of Tennessee, University of York, Old Dominion University, Massachusetts Institute of Technology, Old Dominion University, Massachusetts Institute of Technology, Lawrence Berkeley National Laboratory, University of California, Berkeley, Institute of Physics - University of Sao Paulo, Naval Research Laboratory, St. Cloud State University, University of Illinois at Urbana-Champaign, Space Sciences Laboratory, Virginia Polytechnic Institute and State University, Space Sciences Laboratory, University of California Berkeley, University of Maryland - Baltimore County, Sandia National Laboratories, Pacific Northwest National Laboratory, Federal University of Bahia; University of Brasília, Federal University of Bahia, Department of Applied Physics, Yale University & Department of Physics, Yale University, Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Department of Physics, University of Illinois at Urbana-Champaign & Current affiliation: Seagate Research Group, Seagate Technology, Department of Physics and Astronomy, Wayne State University, Department of Physics, University of Illinois at Urbana-Champaign, Department of Applied Physics, Yale University, Swarthmore College, Western Washington University, Departments of Chemistry and Physics and The Baruch 60 Center for Biochemical Solar Energy Research at Rensselaer Polytechnic Institute, University of Florida, Wayne State University, Vanderbilt University, University of Maryland, College Park, NASA GSFC, CfA, California Institute of Technology, Skidmore College, Durham University, University of Alberta, University of Michigan, Curtin University, Michigan State University, University of Nevada, University of Chicago, Duke University, Cornell, Pennsylvania State University, New York University Abu Dhabi, NASA Ames Research Center, Kenyon Coll, Kenyon College, University of Texas at Austin, Flatiron Institute, University of California, Los Angeles, Ohio State University, University of Pennsylvania, HERA, HERA, Rochester Institute of Technology, Howard Community College, Carleton College, California State University at Long Beach, Bishop Ireton High School, Fayetteville State University, Univ of Oklahoma, University of Massachusetts Amherst, Carnegie Observatories, San Diego State University, Associate of the National Institute of Standards and Technology, National Institute of Standards and Technology, NTT Basic Research Laboratories and NTT Research Center for Theoretical Quantum Physics, JILA, University of Colorado, 440 UCB, Boulder, CO, Department of Physics, 390 UCB University of Colorado, University of Washington, James Franck Institute, Enrico Fermi Institute, University of Chicago Department of Physics, Princeton University, Department of Physics, Arizona State University, Indiana Univ - Bloomington, National Autonomous University of Mexico, Harvard University, Nagoya University, Toyota Technological Institute, University of Tokyo, Zhejiang University, Clark University, Natl Univ of Singapore, University of Richmond