Development of a new over‐water Advanced Very High Resolution Radiometer dust detection algorithm

Abstract

Abstract A new over–water dust detection algorithm is developed and applied to the 5–channel Advanced Very High Resolution Radiometer (AVHRR) imager onboard the National Oceanic and Atmospheric Administration series of polar orbiting satellites. The algorithm has been developed to improve the distinction between dust and meteorological clouds for very optically thick dust storms that would have previously been flagged as cloud under the Clouds from AVHRR Extended cloud mask algorithm. The algorithm has been assessed by making daily comparisons with data from the Aerosol Robotic Network and by making a climatological comparison with METEOSAT and Total Ozone Mapping Spectrometer data over a portion of the North Atlantic. The new algorithm improves the separation of clouds and airborne dust. Application of the new product to the 5–channel AVHRR historic data sets can provide information on the global dust signal, especially on an interannual time scale. Acknowledgements Funding for this research was provided by the NOAA/NESDIS Polar Program and the NOAA/NESDIS/ORA AVHRR Reprocessing Program. The authors would like to thank Dr Isabelle Chiapello for providing TOMS and METEOSAT wintertime dust data and Dr Steve Ackerman, Dr Grant Petty, and Dr Dan Vimont for their comments on the overall work. We also would like to thank Didier Tanré, Sang‐Woo Kim, Robert Frouin, Hammad Benchekroun, Brent Holben and their staff for establishing and maintaining the Capo Verde, Che‐Ju, San Nichols and Dahkla AERONET sites used in this investigation. We are grateful to the reviewers for their insightful and constructive comments. The views, opinions, and findings contained in this report are those of the authors and should not be construed as an official National Oceanic and Atmospheric Administration or US Government position, policy, or decision.