acp-15-8479-2015.pdf (9.44 MB)
Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations
journal contribution
posted on 2023-06-08, 22:35 authored by C L Ryder, J B McQuaid, C Flamant, R Washington, H E Brindley, E J Highwood, J H Marsham, D J Parker, Martin ToddMartin Todd, J R Banks, J K Brooke, S Engelstaedter, V Estellés, P Formenti, L Garcia-Carreras, C Kocha, F Marenco, P Rosenberg, H Sodemann, C J T Allen, A Bourdon, M Bart, C Cavazos-Guerra, S Chevaillier, J Crosier, E Darbyshire, A R Dean, J R Dorsey, J Kent, D O'Sullivan, K Schepanski, K Szpek, A WoolleyThe Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under light dust loadings. These results provide insights into boundary layer and dust processes in the SHL region – a region of substantial global climatic importance.
Funding
Fennec - The Saharan Climate System; G0400; NERC-NATURAL ENVIRONMENT RESEARCH COUNCIL; NE/G01826X/1
History
Publication status
- Published
File Version
- Published version
Journal
Atmospheric Chemistry and Physics DiscussionsISSN
1680-7375Publisher
European Geosciences UnionExternal DOI
Issue
1Volume
15Page range
199-290Department affiliated with
- Geography Publications
Research groups affiliated with
- Sussex Sustainability Research Programme Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2015-09-21First Open Access (FOA) Date
2019-08-16First Compliant Deposit (FCD) Date
2019-08-16Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC