Abstract
As the most significant interannual variability in the climate system, El Niño-Southern Oscillation (ENSO) has critical effects on global weather and climate patterns. To simulate and predict ENSO, coupled general circulation models (CGCMs) have become a key tool. However, the accurate simulation of ENSO is still a challenge for CGCMs. The performance of El Niño simulations conducted through FIO-ESM v1.0 is examined based on the outputs of the Coupled Model Intercomparsion Project phase 5 (CMIP5) historical experiments. The results show that FIO-ESM v1.0 suffers from similar common problems to other CMIP5 models, including an eastward shift in the central locations of El Niño, adopting a regular period of roughly 3 years, addressing excessively high amplitude, spurious eastward propagation of El Niño events, and Aborted El Niño events. El Niño composite and mixed layer heat budget analyses indicate that these simulation biases are mainly associated with the mean state biases, including a warm Sea Surface Temperature (SST) bias for the central-eastern Pacific, a cold SST bias for the western and central Pacific, seasonal cycles of SST of the equatorial eastern Pacific, and weaker trade winds. Weaker SST-cloud-shortwave radiation feedback in La Niña events than in El Niño events is what creates spurious ENSO amplitude symmetry in the model. We suggest that the improvement of El Niño simulations may be realized by focusing on the mean state and SST-cloud-shortwave radiation feedback in the tropical region. Specifically, further incremental improvements in the mean state of the tropical Pacific should constitute the first step to realizing more accurate ENSO simulation.
Highlights
El Niño-Southern Oscillation (ENSO) is the strongest interannual variability and large-scale coupled atmosphere–ocean phenomenon that occurs in the climate system (Philander 1983, 1990; Wang and Picaut 2004; Sarachik and Cane 2010)
We found that Aborted El Niño events are stronger than the winter El Niño events (Fig. 2b), and the amplitudes of the winter El Niño events with peaks occurring in Nov(0) or Dec(0) were larger than those with peaks occuring in Jan(1)
FIO-ESM v1.0 El Niño simulations based on its Coupled Model Intercomparsion Project phase 5 (CMIP5) historical experiment outputs were evaluated
Summary
El Niño-Southern Oscillation (ENSO) is the strongest interannual variability and large-scale coupled atmosphere–ocean phenomenon that occurs in the climate system (Philander 1983, 1990; Wang and Picaut 2004; Sarachik and Cane 2010) It affects the sea surface temperature (SST), precipitation, and atmospheric circulation in the tropics but. The model exhibits good performance in terms of ENSO diversity (Matveeva et al 2018), spatial distributions of SST peaks during El Niño events (Graham et al 2017), relationships between ENSO and the Northern Hemisphere polar region (Roy et al 2019), and ENSO predictions (Song et al 2015) It still suffers from similar ENSO simulation biases similar to those of other CMIP5 models (Bellenger et al 2014; Taschetto et al 2014; Yun et al 2016). Further information on FIO-ESM v1.0 can be found in Qiao et al (2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
