Matveeva T., Gushchina D., Dewitte Boris. (2018). The seasonal relationship between intraseasonal tropical variability and ENSO in CMIP5. Geoscientific Model Development, 11 (6), p. 2373-2392. ISSN 1991-959X.
Titre du document
The seasonal relationship between intraseasonal tropical variability and ENSO in CMIP5
Geoscientific Model Development, 2018,
11 (6), p. 2373-2392 ISSN 1991-959X
The El Nino-Southern Oscillation (ENSO) is tightly linked to the intraseasonal tropical variability (ITV) that contributes to energise the deterministic ocean dynamics during the development of El Nino. Here, the relationship between ITV and ENSO is assessed based on models from the Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5) taking into account the so-called diversity of ENSO, that is, the existence of two types of events (central Pacific versus eastern Pacific El Nino). As a first step, the models' skill in simulating ENSO diversity is assessed. The characteristics of the ITV are then documented revealing a large dispersion within an ensemble of 16 models. A total of 11 models exhibit some skill in simulating the key aspects of the ITV for ENSO: the total variance along the Equator, the seasonal cycle and the characteristics of the propagation along the Equator of the Madden-Julian oscillation (MJO) and the convectively coupled equatorial Rossby (ER) waves. Five models that account realistically for both the two types of El Nifio events and ITV characteristics are used for the further analysis of seasonal ITV / ENSO relationship. The results indicate a large dispersion among the models and an overall limited skill in accounting for the observed seasonal ITV / ENSO relationship. Implications of our results are discussed in light of recent studies on the forcing mechanism of ENSO diversity.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Sciences du milieu [021]
;
Limnologie physique / Océanographie physique [032]
