@article{fdi:010070323,
  title = {{S}easonal cycle of desert aerosols in western {A}frica : analysis of the coastal transition with passive and active sensors},
  author = {{S}enghor, {H}. and {M}achu, {E}ric and {H}ourdin, {F}. and {G}aye, {A}. {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he impact of desert aerosols on climate, atmospheric processes, and the environment is still debated in the scientific community. {T}he extent of their influence remains to be determined and particularly requires a better understanding of the variability of their distribution. {I}n this work, we studied the variability of these aerosols in western {A}frica using different types of satellite observations. {S}ea-{W}i{FS} ({S}ea-{V}iewing {W}ide {F}ield-of-{V}iew {S}ensor) and {OMI} ({O}zone {M}onitoring {I}nstrument) data have been used to characterize the spatial distribution of mineral aerosols from their optical and physical properties over the period 2005-2010. {I}n particular, we focused on the variability of the transition between continental western {A}frican and the eastern {A}tlantic {O}cean. {D}ata provided by the lidar scrolling {CALIOP} ({C}loud-{A}erosol {L}idar with {O}rthogonal {P}olarization) onboard the satellite {CALIPSO} ({C}loud {A}erosol {L}idar and {I}nfrared {P}athfinder {S}atellite {O}bservations) for the period 2007-2013 were then used to assess the seasonal variability of the vertical distribution of desert aerosols. {W}e first obtained a good representation of aerosol optical depth ({AOD}) and singlescattering albedo ({SSA}) from the satellites {S}ea{W}i{FS} and {OMI}, respectively, in comparison with {AERONET} estimates, both above the continent and the ocean. {D}ust occurrence frequency is higher in spring and boreal summer. {I}n spring, the highest occurrences are located between the surface and 3 km above sea level, while in summer the highest occurrences are between 2 and 5 km altitude. {T}he vertical distribution given by {CALIOP} also highlights an abrupt change at the coast from spring to fall with a layer of desert aerosols confined in an atmospheric layer uplifted from the surface of the ocean. {T}his uplift of the aerosol layer above the ocean contrasts with the winter season during which mineral aerosols are confined in the atmospheric boundary layer. {R}adiosondes at {D}akar {W}eather {S}tation (17.5 degrees {W}, 14.74 degrees {N}) provide basic thermodynamic variables which partially give a causal relationship between the layering of the atmospheric circulation over western {A}frica and their aerosol contents throughout the year. {A} {SSA} increase is observed in winter and spring at the transition between the continent and the ocean. {T}he analysis of mean {NCEP} ({N}ational {C}enters for {E}nvironmental {P}rediction) winds at 925 h{P}a between 2000 and 2012 suggest a significant contribution of coastal sand sources from {M}auritania in winter which would increase {SSA} over the ocean.},
  keywords = {{AFRIQUE} {DE} {L}'{OUEST} ; {ATLANTIQUE} {EST}},
  booktitle = {},
  journal = {{A}tmospheric {C}hemistry and {P}hysics},
  volume = {17},
  numero = {13},
  pages = {8395--8410},
  ISSN = {1680-7316},
  year = {2017},
  DOI = {10.5194/acp-17-8395-2017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070323},
}