Fennec is a large-scale, international, multi-institutional, multi-platform, observational, modelling and satellite climate program in the Saharan Heat Low region (southern Algeria, eastern Morocco, Northern Mauritania, Northern Mali and Northern Niger). The Saharan Heat Low is a key component of the West African Monsoon and is the location of the largest mineral aerosol loadings on the planet in the northern summer. The inhospitable, vast area of the Heat Low has virtually no routine meteorological observations. Knowledge of the key atmospheric processes in this important region is therefore very limited and this knowledge deficit results in reduced performance of both weather and climate prediction in and well beyond the north/west African region. The Fennec project is designed to addres