PMID- 34717325
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20211031
IS  - 1089-7682 (Electronic)
IS  - 1054-1500 (Linking)
VI  - 31
IP  - 10
DP  - 2021 Oct
TI  - A flexible data-driven cyclostationary model for the probability density of El 
      Nino-Southern Oscillation.
PG  - 103126
LID - 10.1063/5.0060104 [doi]
AB  - Model simulations of El Nino-Southern Oscillation (ENSO) are usually evaluated by 
      comparing them to observations using a multitude of metrics. However, this 
      approach cannot provide an objective summary metric of model performance. Here, 
      we propose that such an objective model evaluation should involve comparing the 
      full joint probability density functions (pdf's) of ENSO. For simplicity, ENSO 
      state is defined here as sea surface temperature anomalies over the Nino 3 region 
      and equatorial Pacific thermocline depth anomalies. We argue that all ENSO 
      metrics are a function of the joint pdf, the latter fully specifying the 
      underlying stochastic process. Unfortunately, there is a lack of methods to 
      recover the joint ENSO pdf from climate models or observations. Here, we develop 
      a data-driven stochastic model for ENSO that allows for an analytic solution of 
      the non-Markov non-Gaussian cyclostationary ENSO pdf. We show that the model can 
      explain relevant ENSO features found in the observations and can serve as an ENSO 
      simulator. We demonstrate that the model can reasonably approximate ENSO in most 
      GCMs and is useful at exploring the internal ENSO variability. The general 
      approach is not limited to ENSO and could be applied to other cyclostationary 
      processes.
FAU - Olson, Roman
AU  - Olson R
AD  - Irreversible Climate Change Research Center, Yonsei University, Seoul 03722, 
      South Korea.
FAU - Fan, Yanan
AU  - Fan Y
AD  - School of Mathematics and Statistics and UNSW Data Science Hub, UNSW Sydney, 2052 
      Sydney, Australia.
FAU - An, Soon-Il
AU  - An SI
AUID- ORCID: 000000020003429X
AD  - Irreversible Climate Change Research Center, Yonsei University, Seoul 03722, 
      South Korea.
FAU - Kim, Soong-Ki
AU  - Kim SK
AUID- ORCID: 000000016586780X
AD  - Irreversible Climate Change Research Center, Yonsei University, Seoul 03722, 
      South Korea.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Chaos
JT  - Chaos (Woodbury, N.Y.)
JID - 100971574
SB  - IM
EDAT- 2021/11/01 06:00
MHDA- 2021/11/01 06:01
CRDT- 2021/10/31 20:27
PHST- 2021/10/31 20:27 [entrez]
PHST- 2021/11/01 06:00 [pubmed]
PHST- 2021/11/01 06:01 [medline]
AID - 10.1063/5.0060104 [doi]
PST - ppublish
SO  - Chaos. 2021 Oct;31(10):103126. doi: 10.1063/5.0060104.