{"id":"7b264cdb-e609-4186-9203-0be953923c2f","arxiv_id":"2505.01397","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"Hot and warm tidally locked giants with similar Rossby, Froude, and Burger numbers display qualitatively similar circulation patterns, with quantitative differences governed by the Rossby deformation scale.","lead":"Simulations of two tidally locked exoplanets, one hot and one warm, show that their atmospheric circulations look alike when key dynamical numbers match. The study argues that the Rossby deformation scale, not temperature alone, sets the quantitative differences, which is useful for interpreting JWST and Ariel observations.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Similar circulations may reflect the identical thermal forcing anomaly imposed on both planets, not the dynamical parameters; with no control that varies LD independently, the causal attribution is underdetermined.","rationale":"The reader's CONDITIONAL verdict is appropriate. My concern is not that the simulations are incorrect but that the two-planet comparison cannot uniquely support the causal story. The paper compares planets with similar dynamical parameters and, by construction, the same thermal forcing anomaly (Delta-T_DN ~ 100 K at the top, zero at 1 bar). Since the forcing anomaly is the energy source driving the circulation, the observed qualitative similarity could simply be the response to identical forcing, with the dynamical parameters playing a secondary role. The unpublished forcing model (Section 2.2) compounds this because the reader cannot check whether the identical profiles are physically justified, but even if the profiles are accepted, the design confound remains. The paper's additional forcing experiment with an HD 209458b-like profile shows that changing forcing changes zonality, but it is not a control for LD. The attribution of quantitative HP/WP differences to LD is also confounded because LD, H, N, Omega, g, M, and R all change between the two planets; LD is never varied independently. This is an internal-validity issue, not a disagreement with current consensus. The proposed forcing-swap control is concrete and feasible: if the flow tracks the forcing profiles, the central claim overstates the role of dynamics; if the flow tracks the planet, the claim is supported. The simulations themselves are clearly described, use a well-tested pseudospectral code (BoB), and the presented fields and diagnostics are consistent with the reported qualitative patterns. There is no basis for rejection; the condition is that the causal attribution be tested with a control that separates forcing shape from dynamical parameters.","tokens_in":12269,"tokens_out":7844,"duration_ms":83757,"concrete_test":"Run two additional T341L50 simulations with identical numerics and initialization: (i) the warm-planet physical parameters forced with the hot-planet Teq(p) and tau_r(p) profiles, and (ii) the hot-planet physical parameters forced with the warm-planet Teq(p) and tau_r(p) profiles. At t >= 200 tau_p, compare PV and vorticity fields, equatorial jet width, and polar vortex centering with the original runs. If each swapped run resembles the forcing donor rather than the original planet, the similarity is a consequence of the identical forcing anomaly and the dynamical-parameter attribution is not supported. If each swapped run retains its planet's original morphology, the role of LD and the dynamical regime is strengthened.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The decisive weakness is experimental design, not the unpublished forcing model per se. Both simulated planets are forced with the same dayside heating geometry (cos lambda cos phi) and, by construction, the same vertical anomaly profile: Delta-T_DN ~ 100 K at p = 0.05 bar, decreasing linearly in log p to zero at p = 1 bar for both planets (Section 3, Fig. 1). The only thermal differences are the mean Teq and the relaxation timescale tau_r(p). If the qualitative circulation is controlled primarily by the shape and penetration depth of the thermal forcing anomaly, then two planets receiving identical anomalies would look similar regardless of their dynamical numbers. The paper's own HD 209458b-forcing experiment shows that changing the forcing anomaly changes quasi-zonal flows into azonal flows, which demonstrates forcing sensitivity but does not isolate the dynamical parameters. Conversely, the quantitative HP/WP differences are attributed to LD, yet the two planets also differ in mass, radius, gravity, rotation rate, scale height, and Brunt-Vaisala frequency; no simulation varies LD while holding forcing and other parameters fixed. Thus the central claim that comparable Rossby and Froude numbers and LD set the circulation is underdetermined by the two-planet comparison.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript presents high-resolution (T341L50) pseudospectral primitive-equation simulations of two tidally locked giant exoplanets, a hot planet modeled after KELT-11 b and a warmer planet modeled after WASP-39 b. The thermal forcing uses Newtonian relaxation with equilibrium temperature and relaxation time profiles constructed from an as-yet-unpublished self-consistent model. The authors report that, despite markedly different equilibrium temperatures, the two simulations develop qualitatively similar circulation patterns: quasi-zonal flows, turbulent equatorial flow, persistent polar anticyclones, and wavenumber-2 Rossby waves. They attribute quantitative differences in flow width, amplitude, vortex precession, and disk-integrated flux variability to the difference in Rossby deformation length L_D, and they use a quasigeostrophic beta-plane dispersion relation to identify the dominant Rossby mode as n ≈ 3.","tokens_in":12480,"tokens_out":5653,"duration_ms":61994,"significance":"If the causal attribution were established, the paper would make a useful contribution: it would show that qualitative circulation regimes of hot and warm tidally locked giants are controlled by nondimensional dynamical parameters (Rossby, Froude, Burger numbers) rather than by equilibrium temperature alone, with direct implications for interpreting phase curves and JWST/Ariel observations. The paper has real strengths: the code is well-tested and convergence-checked, both planets are run at identical resolution for long integration times, and the diagnostics (potential vorticity, relative vorticity, Hovmöller plots, disk-averaged flux time series) are appropriate and clearly presented. However, the central causal claim is underdetermined by the current experimental design: the two simulations share nearly identical thermal forcing geometry and vertical anomaly shape, so the qualitative similarity may reflect the forcing rather than the dynamical parameters, and no control experiment varies L_D while holding other parameters fixed. The unpublished forcing model also limits reproducibility.","major_comments":[{"comment":"The central claim that the qualitative circulation similarity is caused by comparable Rossby and Froude numbers, and that quantitative differences are caused by L_D, is underdetermined by the present design. Both planets are forced with the same lateral modulation cos λ cos φ and, by construction, the same vertical anomaly profile (ΔT_DN ≈ 100 K at 0.05 bar, decreasing linearly in log p to zero at 1 bar), yet they also differ in mass, radius, gravity, rotation rate, scale height, Brunt–Väisälä frequency, and wind speed (Table 1). The identical forcing shape alone could plausibly produce the observed qualitative similarity, and the HP/WP differences could be due to any of the simultaneously varying parameters rather than specifically to L_D. The authors should add a control experiment that varies L_D while holding the forcing profiles and other dynamical numbers fixed, or at minimum an experiment that swaps the Teq(p) and τ_r(p) profiles between the two planets; without such a test the attribution to L_D is not established.","section":"Section 3, Figure 1, Table 1"},{"comment":"The Teq(p) profiles that drive both simulations are computed with a self-consistent radiative-transfer/empirical model whose full description, validation, and fit parameters are deferred to an unpublished companion paper ('Skinner et al., in prep.'). Since the forcing profiles enter every result and their identical vertical structure is central to the similarity interpretation, this is a load-bearing reproducibility gap. The manuscript should either provide the essential details of the polynomial fit and validation or cite a publicly available published description; as written, the reader cannot check whether the two planets' forcing profiles are indeed physically consistent or whether the similarity of the circulations is an artifact of the assumed forcing.","section":"Section 2.2"},{"comment":"The Rossby wave analysis is presented as a prediction (\"Equation 2 predicts the dominant linear mode has n ≈ 3\"), but it is actually a consistency check: the phase speed c_p is measured from the simulation, the zonal wavenumber m = 2 is read off the same fields, and Eq. (2) is then inverted to obtain n. The mode structure is subsequently confirmed by visual inspection of the same fields. This circularity does not invalidate the identification, but it should be reframed honestly as a consistency check. The claim would be stronger if the authors specified a mode a priori and compared the predicted phase speed with the measured one, or if they presented the inferred n as a diagnostic rather than an independent prediction.","section":"Section 3, Eq. (2)"}],"minor_comments":[{"comment":"The text states that both planets have Ro ≲ 0.15 and Bu = O(1) in mid-to-high latitude regions, while Table 1 lists characteristic Rossby numbers of 0.45 and 0.32; please clarify that the former values are local, away from the equatorial jet, so the two statements are not contradictory.","section":"Section 3, p. 6"},{"comment":"The text says \"emissivity is assumed to be zero\" immediately after defining a Stefan–Boltzmann disk-averaged flux; a zero-emissivity body emits no thermal flux. This is presumably a typo for emissivity equal to unity (or a blackbody), and it should be corrected.","section":"Section 3, Eq. (3)"},{"comment":"There are several typographical errors that should be fixed, including \"Rossby waves that gives rise\" in the abstract and \"distinct, differences\" in Section 4.","section":"Abstract and Section 4"},{"comment":"The statement that the p = 0.95 bar model fluxes \"match closely to full radiative transfer (RT) fluxes\" is not supported by any comparison shown in the paper, since the dynamical model does not include radiative transfer; please clarify the provenance of this claim.","section":"Figure 5 discussion, Section 3"}],"recommendation":"major_revision","confidential_remarks":"The paper fits the journal's scope and the simulations appear competently executed, but the design embeds part of the desired conclusion in the selection: the two planets were chosen for similar dynamical parameters and then forced with nearly identical thermal anomaly shapes. This is not a sign of misconduct, but the authors should state this design choice explicitly and address the underdetermination with additional control experiments or a substantially more cautious interpretation. I would be willing to review a revised version."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"First things first: this paper is worth sending to referees, but the central claim needs work. The qualitative result is real: two tidally locked giants with very different equilibrium temperatures end up with similar quasi-zonal flows, polar vortices, and Rossby waves. That is a genuinely useful data point for the warm-giant regime, which has been under-modeled. The quantitative story—that differences are set by the Rossby deformation scale LD—is not actually established by this design.\n\nThe two planets, KELT-11b and WASP-39b, differ in more than LD: mass, radius, gravity, scale height, Brunt–Väisälä frequency, and rotation rate all differ. More importantly, the thermal forcing anomaly has the same shape and penetration depth for both (ΔT_DN ≈ 100 K at p=0.05 bar, going to zero at p=1 bar). If the circulation pattern is largely controlled by the geometry and depth of the forcing, two planets receiving identical anomaly shapes would look similar regardless of their dynamical numbers. There is no simulation that varies LD while holding the forcing fixed, nor one that holds LD fixed and varies the forcing. The HD 209458b-forcing experiment shows that forcing matters, but it does not isolate LD. So the reader's conditional verdict is right, and the stress-test concern is not manufactured.\n\nTwo smaller points. The 'prediction' of n≈3 from the Rossby dispersion relation is a consistency check: cp and m=2 are measured from the same fields, so it does not independently confirm the wave interpretation. The forcing model is described as self-consistent but is unpublished, and the statement that the p=0.95 bar fluxes 'match closely to full RT fluxes' is asserted without a comparison shown. Both are fixable in revision.\n\nWhat the paper does well: the simulations are clearly described, the code is established, resolution checks are mentioned, and the diagnostics (PV, vorticity, Hovmöller plots) are appropriate. The qualitative similarity between the two planets is well supported by the figures. The HD209458 forcing experiment is a nice control in the right direction. The citation pattern looks normal; the heavy reliance on Skinner & Cho papers is justified given the method, and self-citation is not a problem here.\n\nWho should read it: GCM modelers and observers trying to interpret phase curves and emission maps of warm giants. It deserves a serious referee, but the referee should ask for at least one clean control experiment that varies LD independently of forcing, and a description of the forcing model that is actually in the paper. My recommendation: peer review with major revision, not desk reject.","headline":"A useful two-planet simulation study with a clear qualitative result, but the causal attribution to the Rossby deformation scale is not isolated by the design; worth sending to referees with a demand for control runs.","tokens_in":13057,"tokens_out":2707,"would_cite":false,"duration_ms":26325,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"The large-scale circulation of tidally locked giant planets is set by dynamical numbers, not by equilibrium temperature.","keywords":["Exoplanets","Exoplanet atmospheres","Exoplanet atmospheric dynamics","Hot Jupiters","Warm giant planets","Rossby deformation scale","Tidally locked planets","Hydrodynamic simulations"],"falsifier":"Run the same simulations with the two planets' thermal forcing profiles swapped or reshaped while keeping their dynamical parameters fixed, and check whether the circulation pattern stays qualitatively the same; alternatively, monitor long-baseline phase curves of both planets and look for the predicted flux oscillation amplitudes and periods of roughly $4\\tau_p$ for KELT-11b and $3\\tau_p$ for WASP-39b.","tokens_in":12017,"feed_emoji":"🌀","tokens_out":12044,"duration_ms":108679,"temperature":0.7,"pith_summary":"The paper sets out to show that the broad pattern of a tidally locked giant planet's atmosphere is governed by a few dynamical parameters, not by how hot the planet is. It simulates a KELT-11b-like hot Jupiter and a WASP-39b-like warm Jupiter at identical resolution and with nearly the same thermal forcing shape, while arranging for their Rossby, Froude, and Burger numbers to be comparable. In both simulations the atmosphere organizes into the same qualitative circulation: a turbulent eastward equatorial jet, quasi-zonal mid-latitude flow near 20 degrees, anticyclonic polar vortices, and large-scale Rossby waves. The differences that do appear, such as jet width and strength, whether polar vortices sit on the pole or precess, and the amplitude and period of disk-integrated flux oscillations, track the difference in Rossby deformation scale. If the claim holds, the observable weather of warm giant planets can be predicted from dynamical similarity rather than from equilibrium temperature alone.","feed_headline":"Temperature is not what sets a giant planet's weather","feed_subtitle":"Simulations of KELT-11b and WASP-39b suggest Rossby and Froude numbers control the weather, not temperature.","key_machinery":"The argument is carried by a parameter-similarity construction rather than by a single formula. The planets are chosen so that their Rossby number $Ro$, Froude number $Fr$, Burger number $Bu = (L_D/L)^2$, and deformation scale $L_D$ are comparable; the qualitative circulation is then read as a function of this dynamical regime. Within that regime, $L_D$ does the quantitative work: it sets the horizontal length scale over which waves and vortices interact, so a larger $L_D$ widens the equatorial jet, softens its potential-vorticity gradients, and lets polar vortices couple to and precess around the equatorial flow. The interpretation of the deep Rossby waves uses the quasi-geostrophic $\\beta$-plane dispersion relation $c_p = -\\beta/(n(n+1)/R^2 + 1/L_D^2)$, which with the planets' parameters predicts a dominant total wavenumber $n \\approx 3$ and the observed mode-2, period-about-$3\\tau_p$ waves, matching the simulations.","core_discovery":"On the paper's own terms, the result is that two tidally locked gas giants with markedly different equilibrium temperatures, KELT-11b and WASP-39b, develop atmospherically similar circulation when their key dynamical numbers match. The common pattern consists of a broad prograde equatorial flow with turbulent vortices and Rossby-wave undulations, quasi-zonal flow in the extratropics, and a cyclonic ring around an anticyclonic polar vortex in each hemisphere. Quantitative contrasts are attributed to the Rossby deformation scale $L_D$: the hot planet's larger $L_D$ (about $1.5R$) produces broader, roughly 60 to 100 percent stronger equatorial potential-vorticity features, more pronounced wave undulations, and polar vortices that are displaced from the pole and precess with a period near $4\\tau_p$, whereas the warm planet's smaller $L_D$ (about $R$) produces a narrower jet, sharper potential-vorticity gradients on the jet flanks, and centered polar vortices. The paper's central claim is that the qualitative circulation regime depends on the dynamical parameter set, with equilibrium temperature entering mainly through its secondary influence on $L_D$, not as the controlling variable.","pith_inferences":["I would read the paper as implying that the hot versus warm giant-planet division is not a dynamical classification; replacing it with a similarity grouping in $(Ro, Fr, Bu, L_D)$ space would make circulation predictions portable across planets that are observationally very different.","A direct extension is to simulate a planet with WASP-39b's temperature but KELT-11b's deformation scale, or vice versa; the paper's logic predicts the circulation should follow $L_D$, not temperature.","Because the two forcing profiles were intentionally given the same shape, the cleanest test of the paper's interpretation is a twin simulation in which the forcing shapes are allowed to differ; if the circulation pattern breaks, forcing shape is doing part of the organizing work.","The predicted flux oscillation periods of a few orbit periods are within reach of long-baseline JWST phase-curve monitoring, so the dynamical-similarity claim is observationally testable rather than purely numerical."],"forward_implications":["Giant exoplanets currently classified as hot or warm should be expected to share the same qualitative circulation whenever their Rossby, Froude, and Burger numbers and deformation scale are similar, regardless of equilibrium temperature.","The Rossby deformation scale, not temperature, sets the width and strength of the equatorial jet, the geometry of polar vortices, and therefore the amplitude and period of time-variable disk-integrated flux.","Phase-curve and emission-map observations from current and upcoming space telescopes can be used to infer which dynamical regime a planet sits in, because the simulations predict specific flux oscillation periods and amplitudes near $4\\tau_p$ for the hot planet and $3\\tau_p$ for the warm planet.","If the thermal forcing is made strong and deep, as for HD 209458b, the circulation of both planets becomes predominantly azonal, so forcing strength controls whether the quasi-zonal regime is realized at all."],"supporting_citations":[{"why":"Supplies the Newtonian relaxation thermal forcing scheme that drives the simulated circulations.","marker":"A. P. Showman & T. Guillot 2002"},{"why":"Establishes the parameter-based classification of giant-planet circulations that motivates choosing these two planets.","marker":"J. Y-K. Cho et al. 2008"},{"why":"Provides the primitive-equation model and numerical setup the simulations are identical to.","marker":"J. W. Skinner & J. Y.-K. Cho (2025)"},{"why":"Gives the physical parameters of KELT-11b used for the hot-planet simulation.","marker":"J. Pepper et al. 2017"},{"why":"Gives the physical parameters of WASP-39b used for the warm-planet simulation.","marker":"F. Faedi et al. 2011"},{"why":"Underlies the self-consistent thermal forcing profiles and the choice of pressure range from mid-infrared contribution functions.","marker":"Q. Changeat et al. 2024"},{"why":"Defines the potential vorticity and Rossby deformation scale used to interpret the flows.","marker":"A. Gill 1982"},{"why":"Supplies the quasi-geostrophic beta-plane Rossby wave dispersion relation used to identify the mode-2 waves.","marker":"F. B. Lipps 1964"},{"why":"Supports the claim that a smaller deformation scale sharpens potential-vorticity gradients on jet flanks.","marker":"D. Dritschel & M. McIntyre 2008"}],"fun_headline_variants":["Hot and warm giant exoplanets share weather when dynamics match","For giant planets, dynamics beat temperature in setting circulation","Rossby and Froude numbers, not heat, govern giant exoplanet weather","Similar dynamical regimes yield alike circulation on hot and warm giants","Giant exoplanet circulation: same pattern despite big temperature gap"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"Everything rests on the two planets being given essentially the same day-night forcing pattern, with the vertical profile of the temperature difference having the same shape and going to zero at 1 bar, so the shared circulation may largely reflect the shared forcing rather than the shared dynamical numbers standing alone.","fun_headline_variants_meta":{"raw":{"variants":["Hot and warm giant exoplanets share weather when dynamics match","For giant planets, dynamics beat temperature in setting circulation","Rossby and Froude numbers, not heat, govern giant exoplanet weather","Similar dynamical regimes yield alike circulation on hot and warm giants","Giant exoplanet circulation: same pattern despite big temperature gap"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000529,"raw_usage":{"total_tokens":2556,"prompt_tokens":958,"completion_tokens":1598,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":574,"completion_tokens_details":{"reasoning_tokens":1509}},"tokens_in":574,"tokens_out":1598,"duration_ms":12592,"temperature":1.0,"reasoning_tokens":1509,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-16T04:20:56.231471+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Run the same simulations with the two planets' thermal forcing profiles swapped or reshaped while keeping their dynamical parameters fixed, and check whether the circulation pattern stays qualitatively the same; alternatively, monitor long-baseline phase curves of both planets and look for the predicted flux oscillation amplitudes and periods of roughly $4\\tau_p$ for KELT-11b and $3\\tau_p$ for WASP-39b.","supporting_citations":[{"cited_title":"W., & Cho, J","cited_arxiv_id":null,"evidence_quote":"Provides the primitive-equation model and numerical setup the simulations are identical to."},{"cited_title":"E., Collins, K","cited_arxiv_id":null,"evidence_quote":"Gives the physical parameters of KELT-11b used for the hot-planet simulation."},{"cited_title":"C., Anderson, D","cited_arxiv_id":null,"evidence_quote":"Gives the physical parameters of WASP-39b used for the warm-planet simulation."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the quasi-geostrophic beta-plane Rossby wave dispersion relation used to identify the mode-2 waves."},{"cited_title":"2008, Journal of the Atmospheric Sciences, 65, 855","cited_arxiv_id":null,"evidence_quote":"Supports the claim that a smaller deformation scale sharpens potential-vorticity gradients on jet flanks."}],"review_version":1}