Observations of the impact of a major Saharan dust storm on the atmospheric radiation balance

[1] Saharan dust storms have often been observed from space, but the full impact on the Earth’s radiation balance has been difficult to assess, due to limited observations from the surface. We present the first simultaneous observations from space and from a comprehensive new mobile facility in Niamey, Niger, of a major dust storm in March 2006. The results indicate major perturbations to the radiation balance both at the top of the atmosphere and at the surface. Combining the satellite and surface data, we also estimate the impact on the radiation balance of the atmosphere itself. Using independent data from the mobile facility, we derive the optical properties of the dust and input these and other information into two radiation models to simulate the radiative fluxes. We show that the radiation models underestimate the observed absorption of solar radiation in the dusty atmosphere. Citation: Slingo, A., et al. (2006), Observations of the impact of a major Saharan dust storm on the atmospheric radiation balance, Geophys. Res. Lett., 33, L24817,

[1]  Evgueni I. Kassianov,et al.  Retrieval of aerosol microphysical properties using surface MultiFilter Rotating Shadowband Radiometer (MFRSR) data: Modeling and observations , 2005 .

[2]  N. C. Strugnell,et al.  First operational BRDF, albedo nadir reflectance products from MODIS , 2002 .

[3]  Mark A. Miller,et al.  The Arm Mobile Facility and Its First International Deployment: Measuring Radiative Flux Divergence in West Africa , 2007 .

[4]  Catherine Gautier,et al.  SBDART: A Research and Teaching Software Tool for Plane-Parallel Radiative Transfer in the Earth's Atmosphere. , 1998 .

[5]  Nicolas Clerbaux,et al.  Can desert dust explain the outgoing longwave radiation anomaly over the Sahara during July 2003 , 2005 .

[6]  J. Schmetz,et al.  AN INTRODUCTION TO METEOSAT SECOND GENERATION (MSG) , 2002 .

[7]  B. Barkstrom,et al.  Clouds and the Earth's Radiant Energy System (CERES): An Earth Observing System Experiment , 1996 .

[8]  J. Schmetz,et al.  Supplement to An Introduction to Meteosat Second Generation (MSG) , 2002 .

[9]  K. Evans The Spherical Harmonics Discrete Ordinate Method for Three-Dimensional Atmospheric Radiative Transfer , 1998 .

[10]  P. Formenti,et al.  Radiative properties and direct radiative effect of Saharan dust measured by the C-130 aircraft during SHADE: 1. Solar spectrum , 2003 .

[11]  A. Prata A new long‐wave formula for estimating downward clear‐sky radiation at the surface , 1996 .

[12]  O. Boucher,et al.  A satellite view of aerosols in the climate system , 2002, Nature.

[13]  V. Pope,et al.  The impact of new physical parametrizations in the Hadley Centre climate model: HadAM3 , 2000 .

[14]  C. Velden,et al.  ARTICLES: The Impact of the Saharan Air Layer on Atlantic Tropical Cyclone Activity. , 2004 .

[15]  Piet Stammes,et al.  Effect of aerosols on the downward shortwave irradiances at the surface: Measurements versus calculations with MODTRAN4.1 , 2004 .

[16]  Stephen E. Schwartz,et al.  Comparison of model-estimated and measured diffuse downward irradiance at surface in cloud-free skies , 2000 .

[17]  Peter J. Lamb,et al.  African Droughts and Dust Transport to the Caribbean: Climate Change Implications , 2003, Science.

[18]  R. Allan,et al.  Exploitation of Geostationary Earth Radiation Budget data using simulations from a numerical weather prediction model: Methodology and data validation , 2005 .

[19]  N. Mahowald,et al.  Atmospheric global dust cycle and iron inputs to the ocean , 2005 .

[20]  J. Michalsky,et al.  Objective algorithms for the retrieval of optical depths from ground-based measurements. , 1994, Applied optics.

[21]  Daryl R. Myers,et al.  A method to calibrate a solar pyranometer for measuring reference diffuse irradiance , 2003 .

[22]  B. McArthur,et al.  Baseline surface radiation network (BSRN/WCRP) New precision radiometry for climate research , 1998 .

[23]  C. Thorncroft,et al.  African Monsoon Multidisciplinary Analysis: An International Research Project and Field Campaign , 2006 .

[24]  J. Barnard,et al.  Radiative Closure Studies for Clear Skies During the ARM 2003 Aerosol Intensive Observation Period , 2006 .

[25]  Gerald M. Stokes,et al.  The Atmospheric Radiation Measurement Program , 2003 .

[26]  Andreas H. Fink,et al.  Synoptic and dynamic aspects of an extreme springtime Saharan dust outbreak , 2006 .

[27]  D. Corney,et al.  The Geostationary Earth Radiation Budget project , 2005 .

[28]  Richard Washington,et al.  Dust and the low‐level circulation over the Bodélé Depression, Chad: Observations from BoDEx 2005 , 2006 .