@article{fdi:010069500,
  title = {{I}mpact of the observed extratropics on climatological simulations of the {MJO} in a tropical channel model},
  author = {{H}all, {N}. {M}. {J}. and {T}hibaut, {S}. and {M}archesiello, {P}atrick},
  editor = {},
  language = {{ENG}},
  abstract = {{A} regional model is used to quantify the influence of the extratropics on simulated tropical intraseasonal variability. {T}he {W}eather {R}esearch and {F}orecasting ({WRF}) model is run in tropical channel mode with the boundaries at 30{N} and {S} constrained to 6-hourly reanalysis data. {E}xperiments with modified boundary conditions are carried out in which intraseasonal (20-100 days) timescales are removed, or in which only the annual and diurnal cycles are retained. {T}win runs are used to give an objective measure of the boundary-independant component of the variance in each case. {T}he model captures {MJO}-like propagating structures and shows greater zonal-wind variance in runs with full boundary conditions. {C}omparison between experiments indicates that about half the intraseasonal variance can be attributed to boundary influence, and specifically to the presence of an intraseasonal extratropical signal. {T}his signal is associated with stronger correlations between low-level zonal wind precursors in the {P}acific sector and {I}ndian {O}cean convective events. {T}emporal coherence between {MJO} events in the model and the observations is analysed by defining four phases based on convectively coupled signals in the low-level zonal wind. {T}he model can only match observed events above the level of chance when intraseasonal boundary information is provided. {R}esults are analysed in terms of 'primary' and 'successive' events. {A}lthough the model hindcast skill is generally poor, it is better for successive events.},
  keywords = {{MJO} ; {I}ntraseasonal variability ; {T}ropical-extratropical interactions ; {R}egional model ; {WRF} ; {PACIFIQUE} ; {OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {48},
  numero = {7-8},
  pages = {2541--2555},
  ISSN = {0930-7575},
  year = {2017},
  DOI = {10.1007/s00382-016-3221-5},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069500},
}