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Titel |
Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations |
VerfasserIn |
C. L. Ryder, J. B. McQuaid, C. Flamant, P. D. Rosenberg, R. Washington, H. E. Brindley, E. J. Highwood, J. H. Marsham, D. J. Parker, M. C. Todd, J. R. Banks, J. K. Brooke, S. Engelstaedter, V. Estellés, P. Formenti, L. Garcia-Carreras, C. Kocha, F. Marenco, 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, J. Trembath, A. Woolley |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 14 ; Nr. 15, no. 14 (2015-07-30), S.8479-8520 |
Datensatznummer |
250119939
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Publikation (Nr.) |
copernicus.org/acp-15-8479-2015.pdf |
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Zusammenfassung |
The Fennec climate programme 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 (Service des Avions Français Instrumentés pour la
Recherche en Environnement) Falcon 20 is described, with specific focus on instrumentation
specially developed for 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 sizes of 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 (Spinning Enhanced Visible Infra-Red
Imager)
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 cloud condensation nuclei (CCN) and ice nuclei (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 Mountains, (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 (AERosol Robotic NETwork) 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. |
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