Articles | Volume 33, issue 3
https://doi.org/10.5194/npg-33-373-2026
© Author(s) 2026. This work is distributed under the Creative Commons Attribution 4.0 License.
An improved noise model for representing westerly wind bursts in the recharge oscillator model of ENSO
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- Final revised paper (published on 20 Jul 2026)
- Preprint (discussion started on 08 Jan 2026)
Interactive discussion
Status: closed
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
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- RC1: 'Comment on egusphere-2025-6535', Anonymous Referee #1, 16 Feb 2026
- RC2: 'Comment on egusphere-2025-6535', Anonymous Referee #2, 28 Apr 2026
- AC1: 'Comment on egusphere-2025-6535', Georg Gottwald, 25 Jun 2026
Peer review completion
AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
AR by Georg Gottwald on behalf of the Authors (25 Jun 2026)
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ED: Referee Nomination & Report Request started (25 Jun 2026) by Christian Franzke
RR by Anonymous Referee #1 (01 Jul 2026)
ED: Publish as is (05 Jul 2026) by Christian Franzke
AR by Georg Gottwald on behalf of the Authors (07 Jul 2026)
This manuscript describes the role of various noise approximations to the role of Westerly Wind bursts (WWBs) on the development of large amplitude El Nino events. The finding that conditional additive and multiplicative (CAM) noise is a reasonable approximation to intermittent WWBs with impacts on asymmetries between El Nino and La Nina events is perhaps not unsurprising given the literature on applications of noise in linear inverse models (LIMs). However the demonstration within a simplified framework of the recharge oscillator model is somewhat novel. In general, this work is well described, clear and accessible to a wide audience. It is entirely appropriate for NPG.
Given the effort to produce the conditional noise model (CON) I am somewhat confused that this is not at all mentioned in the abstract nor why the paper only has a focus on large amplitude El Nino and not on the ability to reproduce the observed La Nina amplitudes.
Specific comments:
Paragraph 1; Line 1: Reference [1] is to an ECMWF tech. report from 1997. I suggest replacing this with a more up to date reference that takes into account the most recent decades.
Paragraph 2; Line 1: What is the "inferred measure of the time-integrated wind stress associated with WWBs"? Is it simply wind stress anomalies? Please explicitly state what is calculated in Figure 1. Also why use CESM rather than a reanalysis e.g. ERA5. I would further suggest combining the observed time integrated wind stress due to WWBs with the observed NINO3 index and demonstrate i.e. quantify the relationship.
Page 2: regarding Gaussian multiplicative noise on East Pacific SST, please provide references to the "... emerging consensus in the ENSO literature".
Page 3: Last sentence before section"Noise Models": missing section number. i.e., "in section ? we will discuss ..."
Sentence following Equation 8: \nu_{2} is undefined.
Page 6: Combine Fig3 with new Fig1 observed WWBs.
Fig 4: Please quantify the differences between observed and estimated variance and skewness. By eye, it appears that OU is a better fit than either CAM or CON.
Fig5: I do not see the relevance of these timeseries segments. Please provide a quantitative measure or drop the figure.
Fig8: Please provide a table with the dates of the chosen events. Further, it is quite obvious that many of these events are not monotonically increasing until at least t=-6 months. Choosing only the 4 most extreme cases does not strengthen the argument when all chosen cases are exceeding the threshold.