Better-than-New LIDAR Provides 24/7 Atmospheric Aerosol Data


Researchers from eight institutions led by Pacific Northwest National Laboratory solved a six year old software and hardware problem that had perplexed scientists studying atmospheric aerosols for climate research. Not only did they fix the problem, but the instrument now performs better than it did when it was new. A lidar, similar to a radar that calculates distances by bouncing radio waves off of objects, measures how light bounces off aerosols in the sky. Aerosols, tiny particles suspended in the atmosphere, absorb and scatter sunlight, which can contribute to climate change. Aerosol measurements from the Raman LIDAR at the DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains site in Oklahoma were substantially off when compared to benchmark data collected by a NASA instrument known as the Ames Airborne Tracking Sunphotometer. The scientists developed new algorithms to substantially improve the accuracy of the Raman LIDAR aerosol data. These improvements will enhance the accuracy of aerosol data and will help reduce scientific uncertainties in computer models used to simulate climate change. Much of the uncertainty in projections of global climate change is due to the complexity of clouds, aerosols, and cloud-aerosol interactions and to the difficulty of incorporating this information into climate models. Improved data processing for the Raman LIDAR will provide quality data to help determine how aerosols affect cloud formation and the energy balance from the sun.


B. Schmid, C.J. Flynn, R.K. Newsom, D.D. Turner, R.A. Ferrare, M.F. Clayton, E. Andrews, J.A. Ogren, R.R. Johnson, P.B. Russell, W.J. Gore and R. Dominguez. August 2009. Validation of aerosol extinction and water vapor profiles from routine Atmospheric Radiation Measurement Program Climate Research Facility measurements, J. Geophys. Res., 114, D22207, doi:10.1029/2009JD012682, Nov. 28, 2009.