@article{fdi:010062535,
  title = {{T}he self-organizing map, a new approach to apprehend the {M}adden-{J}ulian {O}scillation influence on the intraseasonal variability of rainfall in the southern {A}frican region},
  author = {{O}ettli, {P}. and {T}ozuka, {T}. and {I}zumo, {T}akeshi and {E}ngelbrecht, {F}. {A}. and {Y}amagata, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {M}adden-{J}ulian {O}scillation ({MJO}) is the major mode of intraseasonal variability (30-60 days) in the tropics, having large rainfall impacts globally, and possibly on southern {A}frica. {H}owever, the latter impact is not well understood and needs to be further explored. {T}he life cycle of the {MJO}, known to be asymmetric, has been nevertheless analyzed usually through methods constrained by both linearity and orthogonality, such as empirical orthogonal function analysis. {H}ere we explore a non-linear classification method, the self-organizing map ({SOM}), a type of artificial neural network used to produce a low-dimensional representation of high-dimensional datasets, to capture more accurately the life cycle of the {MJO} and its global impacts. {T}he classification is applied on intraseasonal anomalies of outgoing longwave radiation within the tropical region over the 1980-2009 period. {U}sing the {SOM} to describe the {MJO} is a new approach, complimentary to the usual real-time multivariate {MJO} index. {I}t efficiently captures this propagative phenomenon and its seasonality, and is shown to provide additional temporal and spatial information on {MJO} activity. {F}or each node, the subtropical convection is analyzed, with a particular focus on the southern {A}frica region. {R}esults show that the convection activity over the central tropical {I}ndian {O}cean is a key factor influencing the intraseasonal convective activity over the southern {A}frican region. {E}nhanced (suppressed) convection over the central {I}ndian {O}cean tends to suppress (enhance) convection over the southern {A}frican region with a 10-day lag by modulating the moisture transport.},
  keywords = {{I}ntraseasonal variability ; {M}adden-{J}ulian {O}scillation ; {S}elf-organizing ; map ; {S}ubtropical atmosphere response ; {S}outhern {A}frican rainfall},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {43},
  numero = {5-6},
  pages = {1557--1573},
  ISSN = {0930-7575},
  year = {2014},
  DOI = {10.1007/s00382-013-1985-4},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062535},
}