Fennec - The Saharan Climate System

Lead Research Organisation: University of Reading
Department Name: Meteorology


The central Sahara has one of the most extreme climates on Earth. During the northern summer months, a large low pressure system caused by intense sunshine develops over a huge, largely uninhabited expanse of northern Mali, southern Algeria and eastern Mauritania. Temperatures in the high 40s are normal and uplift of dry air through more than 6000m of the atmosphere is routine in what is thought to be the deepest such layer on the planet. This large zone is also where the thickest layer of dust anywhere in the Earth's atmosphere is to be found. Although the central Sahara is extremely remote, it turns out to be vitally important to the world's weather and climate. The large low pressure system drives the West African Monsoon and the dry, dusty air layers are closely related to the tropical cyclones which form over the Atlantic Ocean. Likewise, the dusty air has a strong influence on the way the atmosphere is heated, a process which is poorly understood. It is not surprising that the models we use to predict weather and climate and which are a crucial tool for understanding how the atmosphere works, all have problems in dealing with the central Sahara. Insights into how the climate system works, improving the models and therefore the predictions have all been held back in the case of the Sahara by a lack of measurements of the atmosphere and the processes that make dust and extreme weather. This will always be the case until a team goes to the central Sahara and makes these measurements. A key part of this proposal aims to do just that. We want to set up an array of special instruments, at the surface in two carefully chosen places in the central Sahara, which will monitor the winds, temperatures, dust and so on for an entire year. We will add to this collection for a shorter period of even more intense measurements during the core summer month of June. We plan also to fly a instruments attached to an aeroplane overhead the surface array and across the desert so that we can get an idea of the structure of the atmosphere and how it changes through the day. To find out how dust storms work, we will leave 10 weather stations at places where we think dust storms happen frequently. Satellites play an essential role in measuring weather and climate and are especially useful in remote places. The best available information from satellites will help to quantify how weather and climate works in the Sahara. We also expect to improve the way the satellites are able to make their measurements too. Because models are so important to understanding and predicting weather, we will make heavy use of them in this work. We want to know how well the models work over the Sahara and what can be done to improve them. We are especially interested in seeing whether the models work better if we allow them to deal with small parts of the climate system or whether we can still represent extreme places in the Sahara by ignoring these details in the models.


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Description Airborne Saharan dust contains large particles which we have been able to measure for the first time from the NERC research aircraft during this project. The presence of these particles seems to depend on source mechanism and source region, and age of dust since uplifted. These particles affect the amount of absorption of solar radiation by the dust, which could have an impact on surface solar radiation and climate.
Exploitation Route These results could be used to improve weather and climate models, and to understand visibility forecasts. New measurements are being used to estimate the effect on heating rates in the atmosphere which could be used in dynamical models to examine the importance of dust for determining the structure of the Saharan boundary layer.
Sectors Environment

URL http://fennec.ouce.ox.ac.uk/
Description These findings continue to be used by other researchers, including to test satellite retrievals, to explore heating rate perturbations (MSc student at Reading) and will be used to estimate optical properties for dust in SWAMMA (NERC project started 1 July 2014). Also form part of data set used in NERC Fellowship belonging to Claire Ryder.
First Year Of Impact 2012
Sector Environment
Title FENNEC sizes 
Description PRocessed size distributions and optical properties for Saharan dust measurements from FENNEC aircraft campaigns 
Type Of Material Database/Collection of data 
Year Produced 2012 
Provided To Others? Yes  
Impact Queries from international academics about using data in satellite applications 
Description CALIOP collaboration with Vasilis Pappas 
Organisation University of Ioannina
Country Greece 
Sector Academic/University 
PI Contribution Vasilis Pappas from the University of Ioannina, Greece, visited the University of Reading for 3 months to work on a comparison of satellite measurements of vertical profile with aircraft based measurements. A publication is in preparation
Start Year 2013
Description Netsanet 
Organisation University of Sussex
Department Genome Damage and Stability Centre
Country United Kingdom 
Sector Academic/University 
PI Contribution Provided expertise and access to SOCRATES radiation code for PhD student
Collaborator Contribution PhD student undertaking research
Impact None yet. Paper in preparation
Start Year 2014
Description Into the Cauldron 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Into the Cauldron movie about FENNEC fieldwork shown at EGU (reading PDRA provided commentary for part of the movie)

People had an understanding of the nature of fieldwork in the Sahara
Year(s) Of Engagement Activity 2013
Description Saharan climate session at EGU 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Convened session on Saharan Climate at EGU 2013

requests for paper preprints
Year(s) Of Engagement Activity 2013