Remote ENSO forcing versus local air-sea interaction in QTCM: a sensitivity study to intraseasonal variability

摘要

The skill of a newly designed global atmospheric model of intermediatecomplexity - QTCM (for quasi-equilibrium tropical circulation model) insimulating the teleconnections is investigated. The role of the ENSO remoteforcing over the Pacific surrounding regions is emphasized from sensitivityexperiments to critical parameters of the model. The role of the tropicalintraseasonal variability (ITV) on the simulated ENSO teleconnection patternis estimated using the methodology proposed by Lin et al. (2000) allowing todamp the energy of ITV in the model. The reduction of intraseasonalvariability allows emphasizing the forced response of the atmosphere andeases the detection of local coupled atmosphere-ocean patterns. It was shownthat the simulated ITV has an impact on the ENSO teleconnection pattern bothin the mid-latitudes and in regions of ascending and descending branches ofWalker circulation cells in the tropics.