Methods
The following observations were made in the field:
- Surface meteorology at 2 locations (16° 52' 53" N 18° 32' 54.8" E and 16° 58' 53" N 18° 28' 03.6" E) was observed using Davis Vantage Pro automatic weather stations. Observations include temperature, dew point temperature, wind speed and direction, pressure, solar and UV radiation. Observations were made at 2 minute intervals.
- Boundary layer meteorology. Wind speed and direction was observed using Pilot balloon tracking (PIBAL). Balloon ascents were performed 9 times per day. (Observations from a radiosonde mounted on a kite platform were undertaken until the kite tether snapped!)
- Observations of aerosol properties (optical depth, angstrom exponent, particle size distribution) (i) a Cimel-318 photometer (ii) a suite of microtops handheld photometers.
- Observations of optical and physical properties of near surface dust aerosols (size distribution, spectral absorption efficiency, spectral scattering efficiency, single scattering albedo, mass concentration, and chemical composition) using an in-situ vacuum pump Nuclepore dust sampler.
These will be supplemented by:
- Reanalyses data.
- Estimates of aerosols properties from remote sensing instruments including MODIS, ATSR and TOMS.
- Model simulations of (i) the regional climate using the MM5 regional model and the HadAM3 GCM (ii) dust emission and transport using the TM-3 tracer model.