ENSO feedbacks and their relationships with the mean state in a flux adjusted ensemble

Abstract

in using the total linear BJ index alone to assess the reasons for ENSO amplitude biases and its future change in models.

Dynamical and Thermodynamic Elements of Modeled Climate Change at the East African Margin of Convection

“…It is true that the multimodel mean projects an El Niño‐like state (Collins et al, ; Tierney et al, ), with increased precipitation in the central and eastern equatorial Pacific in all seasons. However, competing feedback processes control intensity, duration, and variability of ENSO events (Ferrett & Collins, ). Discrepancies in the strength of these competing feedbacks could result in an erroneous shift of climate toward an El Niño‐like base state in response to rising greenhouse gases (Cane et al, ; Clement et al, ; Coats & Karnauskas, ; Kohyama et al, ; Kohyama & Hartmann, ).…”

What Controls ENSO‐Amplitude Diversity in Climate Models?

“…The BJ index has been used to study ENSO-amplitude diversity among CGCMs (Ferrett & Collins, 2016;Kim et al, 2014;Kim & Jin, 2011). The BJ index has also been used to study potential ENSO changes in a warmer climate (Ferrett & Collins, 2016;Kim & Jin, 2011). The BJ index has also been used to study potential ENSO changes in a warmer climate (Ferrett & Collins, 2016;Kim & Jin, 2011).…”

“…In theory, a larger BJ index is associated with larger ENSO amplitude. Further, the potential influence from atmospheric noise has been discussed in this context (Ferrett & Collins, 2016). However, this correlation breaks down in models participating in CMIP5 (due to a few outliers).…”

“…One example is the Bjerknes Stability (BJ) index (Jin et al, 2006), which approximates the growth rate of SST anomalies (T) in the eastern equatorial Pacific by the recharge oscillator framework (Jin, 1997) and allows examination of the positive and negative feedbacks relevant to ENSO. The BJ index has been used to study ENSO-amplitude diversity among CGCMs (Ferrett & Collins, 2016;Kim et al, 2014;Kim & Jin, 2011). A recent study by An et al (2017) showed that the diversity in the thermocline feedback is highly correlated to ENSOamplitude diversity.…”

“…A recent study by An et al (2017) showed that the diversity in the thermocline feedback is highly correlated to ENSOamplitude diversity. The BJ index has also been used to study potential ENSO changes in a warmer climate (Ferrett & Collins, 2016;Kim & Jin, 2011). In theory, a larger BJ index is associated with larger ENSO amplitude.…”