@article{fdi:010062701,
  title = {{C}onvection activity over the {G}uinean coast and {C}entral {A}frica during northern spring from synoptic to intra-seasonal timescales},
  author = {{K}amsu-{T}amo, {P}. {H}. and {J}anicot, {S}erge and {M}onkam, {D}. and {L}enouo, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study proposes an overview of the main synoptic, medium-range and intraseasonal modes of convection and precipitation in northern spring ({M}arch-{J}une 1979-2010) over {W}est and {C}entral {A}frica, and to understand their atmospheric dynamics. {I}t is based on daily {N}ational {O}ceanic and {A}tmospheric {A}dministration outgoing longwave radiation and {C}loud {A}rchive {U}ser {S}ervice {T}b convection data, daily {TRMM} and {G}lobal {P}recipitation {C}limatology {P}roject rainfall products and daily {ERA}-{I}nterim reanalysis atmospheric fields. {I}t is first shown that mesoscale convective systems can be modulated in terms of occurrences number and intensity at such time scales. {B}ased on empirical orthogonal function analyses on the 2-90-day filtered data it is shown that the main mode of convective and rainfall variability is located along the {G}uinean coast with a moderate to weak extension over {C}entral {A}frica. {C}orresponding regressed deseasonalised atmospheric fields highlight an eastward propagation of patterns consistent with convectively coupled equatorial {K}elvin wave dynamics. {T}hen a singular spectrum analysis combined with a {H}ierarchical {A}scendant {C}lassification enable to define objectively the main spectral bands of variability within the 2-90-day band, and highlight three main bands, 2-8-, 8-22- and 20-90-day. {W}ithin these three bands, space-time spectral decomposition is used to identify the relative impacts of convectively coupled equatorial {K}elvin, {R}ossby and inertia-gravity waves, as well as {M}adden-{J}ulian {O}scillation ({MJO}) signal. {I}t confirms that eastward propagating signals (convectively coupled equatorial {K}elvin wave and {MJO}) are highly dominant in these convection and precipitation variability modes over the {G}uinean coast during northern spring. {S}o, while rain-producing individual systems are moving westward, their activity are highly modulated by sub-regional and regional scales envelops moving to the east. {T}his is a burning issue for operational forecasting centers to be able to monitor and predict such eastward propagating envelops of convective activity.},
  keywords = {{S}ynoptic variability ; {I}ntra-seasonal variability ; {A}frican monsoon ; {C}onvectively coupled equatorial wave ; {AFRIQUE} {DE} {L}'{OUEST} ; {AFRIQUE} {CENTRALE} ; {ZONE} {EQUATORIALE} ; {SAHARA} ; {GUINEE} {COTE}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {43},
  numero = {12},
  pages = {3377--3401},
  ISSN = {0930-7575},
  year = {2014},
  DOI = {10.1007/s00382-014-2111-y},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062701},
}