Absorption of sunlight by dust as inferred from satellite and ground-basedremote sensing

Dust absorption of solar radiation is not well known due to limitations in the accuracy of in situ measurements. Here we report two new independent re mote sensing techniques that provide sensitive measurements of dust absorpt ion. One uses satellite spectral measurements, the second ground based sky measurements. Both techniques demonstrate that Saharan dust absorption of s olar radiation is several times smaller than the current international stan dards. For example, at wavelength of 0.64 mum the dust single scattering al bedo is reported here as 0.97 +/-0.02 rather than 0.87 +/-0.04 in recent re view.