Dynamics-aerosol-chemistry-cloud interactions in West Africa
Aircraft activities
E-newsletter Sign Up

To subscribe to our E-newsletter please enter your details below and click 'Subscribe'

Full Name: *
Affiliation: *
Email Address: *

During the summer of 2016 three large European research aircraft flew to West Africa to sample the air over the region in a coordinated manner.


The three aircraft involved are German DLR Falcon, UK BAS Twin Otter,  French SAFIRE ATR © C. Flamant 

The main objective for the aircraft detachment was to build robust statistics of cloud properties in Southern West Africa in different chemical landscapes: from the background state over the Gulf of Guinea (marine aerosols or mix between marine aerosols and biomass burning aerosols) to ship/flaring emissions to the coastal strip of polluted megacities to the agricultural areas and forest areas further north, and eventually dust from Sahel/Sahara.

The project brought together three research aircrafts from three countries: the German Deutsches Zentrum für Luft- und Raumfahrt (DLR) Falcon 20, the French Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) ATR 42 and the British Antarctic Survey (BAS) Twin Otter. The aircraft component of the field phase of DACCIWA started on 27 June (first scientific flight on 29 June) and concluded on 16 July 2016 (last scientific flight). The three research aircrafts were deployed from the Lomé Military Airport and conducted a total of over 155 science flight hours, including hours sponsored through 3 European Facility for Airborne Research (EUFAR) projects. The aircrafts were used in different ways based on their strengths, but all three had comparable instrumentation with the capability to do gas-phase chemistry, aerosol and clouds, thereby generating a rich dataset of atmospheric conditions across the region.


Flight routes:
blue BAS TwinOtter,
 green: Safire ATR,
red: DLR Falcon

 

DACCIWA operations were coordinated from the DACCIWA Operations Center (DOC) located in Hotel Onomo in Lomé, ~15-20 minutes away from the Lomé Military Airport. The DOC began operations on 25 June to prepare forecasts for the first potential flight operations and to test communications with the 2 ground-based supersites (Savé, Benin and Kumasi, Ghana) as well as with the ground-based site in Ile-Ife (Nigeria). Forecasting support for the project was resumed on 15 July 2016. Two daily briefing meetings were organized at the DOC during the period of the aircraft detachment, at 1100 and 1900 UTC between 25 June and 15 July.

The overarching objective of the airborne component of the DACCIWA project was to accommodate the objectives of work packages WP3 (Chemistry), WP4 (cloud-aerosol interactions) and WP5 (Radiation) as thoroughly as possible, but also contribute to the experimental strategy of WP1 (Section 3) and WP2 (Section 5). For that purpose, six types of flight objectives were conducted over Togo (detachment base) and surrounding countries (Ivory Coast, Ghana, Benin and Nigeria): (i) Stratus clouds, (ii) Land-sea breeze clouds, (iii) Biogenic emission, (iv) Megacities emission (v) Flaring emission and (vi) Dust and biomass burning aerosol. The focuses of the 3 EUFAR projects were: (i) Ship tracks in the Gulf of Guinea, (ii) Mid-level clouds over Benin and (iii) Low-level atmospheric circulation in the Gulf of Guinea. Flight Plans were engineered so that they could accommodate several objectives.

 
DACCIWA operation center, briefing meeting © C. Flamant
 
Left: SAFIRE ATR scientist during research flight, middle: city of Lomé from aircraft, right: instrumentation inside the aircraft © Sébastien. Chastanet