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

Abstract

The skill of a newly designed global atmospheric model of intermediate complexity - QTCM (for quasi-equilibrium tropical circulation model) in simulating the teleconnections is investigated. The role of the ENSO remote forcing over the Pacific surrounding regions is emphasized from sensitivity experiments to critical parameters of the model. The role of the tropical intraseasonal variability (ITV) on the simulated ENSO teleconnection pattern is estimated using the methodology proposed by Lin et al. (2000) allowing to damp the energy of ITV in the model. The reduction of intraseasonal variability allows emphasizing the forced response of the atmosphere and eases the detection of local coupled atmosphere-ocean patterns. It was shown that the simulated ITV has an impact on the ENSO teleconnection pattern both in the mid-latitudes and in regions of ascending and descending branches of Walker circulation cells in the tropics.