0000000000280118
AUTHOR
Guillaume A. D'almeida
Development of a New Sunphotometer and Establishment of a Network Across Africa for the Investigation of the Transport of Sahara Dust
The matter of this project is the investigation of the large scale south transport of Saharan dust originated by critical weather conditions such as sandstorm and dustvi/ind. A new sensitive sunphoto-meter has been developed for this purpose. With ten instruments a network has been installed southerly of the Sahara across Africa. It is the aim to determine the main sources of the mineral dust and its further transport to the South.
Number, Mass and Volume Distributions of Mineral Aerosol and Soils of the Sahara
Abstract A direct method will be described to determine the complete mineral size distribution in aerosol (xylene-insoluble component) and soils (water-insoluble component) covering a size range from 0.01 up to 100 μm and 1000 μm radius, respectively, by using a combination of a scanning electron microscope, optical microscope and sieving. Aerosol and soil samples from the Sahara have been investigated. All mineral aerosol size distributions indicate a maximum between 0.06 and 0.08 μm radius and mineral particles have been found in the Aitken size range down to 0.02 μm radius. The concentration decrease toward larger particles is not uniform and shows considerable variations below 0.5 μm an…
New sunphotometer for network operation.
A handheld sunphotometer has been developed and is described. It operates for 9 wavelengths in the visible and near infrared. The sensitivity range is rather broad, so it can be used in turbid as well as clear atmospheres. The operation is simple, and a digital readout helps prevent operator biases. The instrument is sun powered and suitable for network operations. Determination of the atmospheric turbidity due to aerosol and the column content of O3, NO2, H2O is possible.