Related Programmes

The African Monsoon Multidisciplinary Analysis (AMMA) is a major international experiment to study the West African monsoon system during 2006. It includes the Dust and Biomass Experiment, DABEX in January to February, which will study the aerosols from both biomass burning and Saharan dust outbreaks (bottom left). In the summer, AMMA will focus on aspects of deep convection in the region where the ITCZ meets the Saharan Air Layer (bottom right). Dynamical interactions in this region influence the growth of tropical depressions that can grow into Atlantic hurricanes.

Aircraft measurements will make an important contribution to AMMA and DABEX. The new UK research aircraft, operated by the Facility for Airborne Atmospheric Measurements (FAAM), will be based in Niamey and Dakar.

The US Atmospheric Radiation Measurement (ARM) program runs several comprehensive surface stations (see map right). Unfortunately, none of these is visible from GERB. However, ARM have developed the ARM Mobile Facility (see pictures below) that can be deployed anywhere in the world.

A proposal to send the AMF to Niamey, in Niger, during the AMMA experiment in 2006, almost directly beneath MSG, was submitted by Tony Slingo of ESSC in 2004. The AMF was deployed in late November 2005 and started collecting data from December.

The AMF includes a comprehensive suite of instruments, including radiometers for both broadband and spectrally resolved radiation fields, meteorological measurements and active instruments for probing the vertical structure of the atmosphere.

ARM Mobile Facility (AMF) at Niamey, Niger, Africa

METEOSAT-8 (as MSG-1), the first in a new series of geostationary meteorological satellites was launched on 28th August 2002, and currently operates at longitude 3.4° W. METEOSAT-8 carries the SEVIRI (Spinning Enhanced Visible and Infra-red Radiometer) instrument and the GERB (Geostationary Earth Radiation Budget) scientific instrument. METEOSAT-9 (as MSG-2) was launched on 21st December 2005 and is scheduled to move to 0° in August 2006. The SEVIRI and GERB sensors on this satellite are operating successfully.

SEVIRI images the Earth disk at visible through infra-red wavelengths in 12 channels ranging from 0.4µm to 13µm, at a spatial resolution of 1 (visible channels) to 3 km (IR channels) every 15 minutes.

GERB (see schematic below) is the first broadband radiometer in geostationary orbit, and will be flown on METEOSAT-10 and 11. (Harries et al., Bull. Amer. Meteorol. Soc., in press). The basic GERB resolution at nadir is ~40 km, but combined processing using SEVIRI leads to the ARCH resolution-enhanced product shown bottom right.