REVIEW 4 major objections 5 minor 2 references
Martian atmospheric disturbances from orbital images and surface pressure at Jezero Crater, Mars, during Martian Year 36
T0 review · 4 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash
Pith's one-line read A year of Perseverance pressure data and orbiting images shows that Mars's 2-4 sol weather waves are baroclinic disturbances that grow with dust, and that regional dust storms double the daily pressure tides while shifting their phases in…
desk verdict Solid full-year Jezero pressure climatology; the 'model agreement' claim overstates support because the GCM run is dust-nudged. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The analysis rests on two linked tools. The first is the decomposition of the rover's pressure time series into six thermal-tide components, with periods of 24, 12, 8, 6, 4.8, and 4 hours, plus residual long-period oscillations obtained by subtracting the daily mean and seasonal trend. The second is baroclinic instability theory, quantified through the baroclinic index, the standard growth-rate estimate for weather disturbances powered by horizontal temperature contrasts; the paper evaluates it using climatological wind and temperature profiles near 60°N. Orbital images provide the spatial counterpart, showing polar-edge dust cyclones, the double annular cyclone, and the Aphelion Cloud Belt at known distances from Jezero. A Mars global climate model simulation, forced with that year's observed dust opacity maps, is the quantitative check connecting the dust cycle to the seasonal growth of wave amplitude.
What would settle it
A decisive test would be to run the same Mars global climate model without prescribing the observed Martian Year 36 dust opacity, using climatological dust instead, and check whether the 2-4 sol pressure oscillations still grow by a factor of two to four during the dusty season; if they do not, the reported agreement is an artifact of the dust forcing. A complementary check would compare Jezero pressure with the simultaneous pressure records at Gale, InSight, and Zhurong to verify that the 2-4 sol oscillations are coherent traveling waves with wavenumbers 1-3 rather than local noise.
Extended reading notes
Core claim
The paper's central claim is that Jezero's pressure record over Martian Year 36 splits cleanly into two dynamical regimes governed by dust. In the clear first half of the year, long-period pressure oscillations have small peak-to-peak amplitudes, averaging about 1.6 Pa. In the dusty second half they average about 4.2 Pa with peaks above 18 Pa, and the largest event, regional dust storm C, produced an oscillation of about 22 Pa just before the local dust maximum. The paper identifies these 2-4 sol oscillations as baroclinic waves from the northern hemisphere, compatible with the arc-shaped, spiral, and ring-like cyclones seen at the North Polar Cap edge in orbital images, and reports that a Mars global climate model run with the observed year's dust field reproduces the seasonal trend in amplitude and period. For the thermal tides, the diurnal and semidiurnal amplitudes rose by roughly a factor of two during each of the four dust storms, while the diurnal phase fell and the semidiurnal phase rose, a pattern the paper notes agrees with the response recorded at the Viking landers.
Load-bearing premise
The load-bearing premise is that the climate-model simulation is a fair test of the wave behavior even though its dust field is inserted from observed opacity maps whenever the simulated dust is too low; if the dust forcing, rather than the atmosphere's intrinsic baroclinic response, is what produces the agreement, the validation claim weakens.
Editorial extensions
If this is right
- Dust loading is the main seasonal switch: long-period wave amplitudes at Jezero grow from an average of 1.6 Pa in the clear season to 4.2 Pa in the dusty season, with peaks above 18 Pa.
- Regional dust storms act on the tides in a stereotyped way, raising diurnal and semidiurnal amplitudes by roughly a factor of two (10-20 Pa) while the diurnal phase drops and the semidiurnal phase rises.
- The 2-4 sol pressure oscillations are the surface expression of baroclinic waves generated near the North Polar Cap edge, so a rover at 18°N can sense high-latitude weather systems from 1,500 to 4,500 km away.
- Tide amplitudes track optical depth only during the dusty half-year; in the aphelion cloud belt the diurnal and semidiurnal components follow opposing trends tied to water-ice clouds.
- Tidal phase changes can begin 1-3 sols before the local dust opacity peaks, so pressure tides may act as an early indicator of approaching dust storms.
Reading between the lines
- The climate-model agreement is not a free prediction, because the model is constrained with the observed dust opacity maps; a fairer test of the baroclinic interpretation would rerun the model with climatological dust and see whether the wave amplitude still grows.
- If a polar-edge cyclone's pressure influence really extends two to three times beyond its visible dust and cloud size, then simultaneous pressure records at Jezero, Gale, InSight, and Zhurong during this same year could map high-latitude storm passages that imaging alone cannot track.
- The full-day phase reversal during dust storm C, occurring before the local opacity maximum, suggests the tide reacts to the horizontal spread of dust over thousands of kilometres rather than just the local column; that could make tide phase a remote gauge of dust-storm extent.
- The empirical tide-opacity combination (roughly half diurnal, half semidiurnal, with small contributions from higher components) is fit to one year at one site; checking whether the same weights hold in other years and at other landers would show whether it is a general Martian relation or a local seasonal accident.
Signed reviews
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper presents a one-Martian-year (MY36 to early MY37) study of atmospheric disturbances at Jezero Crater, combining Perseverance MEDA surface-pressure measurements with orbital imaging from MEX/VMC and MRO/MARCI. It characterizes thermal tides up to the sixth component, long-period (>1 sol) pressure oscillations, dust storms, the Aphelion Cloud Belt, and polar cyclones, and it correlates the seasonal evolution of tidal amplitudes and phases with local aerosol optical depth. The central claims are that the four identified dust storms increased diurnal and semidiurnal tidal amplitudes while producing inverse phase responses, and that the dominant 2-4 sol pressure oscillations are baroclinic in origin, with amplitudes that increase with dust content and with periods and amplitudes in good agreement with LMD Martian PCM simulations. A supporting survey of polar-cap-edge cyclones suggests that some of the observed pressure oscillations may be linked to distant cyclonic vortices.
Significance. If the results hold, the paper provides a valuable multi-instrument, full-season record of Martian synoptic and planetary-scale disturbances at a single site, extending earlier work (Paper 1) to a complete Martian year and adding higher-order tidal components (S1-S6). The descriptive catalog of polar cyclones, dust storms, and their apparent pressure signatures is a useful reference for future comparative studies with other landers. The paper's strengths include the use of established, publicly available pressure-reduction methods, the explicit comparison with MCD and MarsWRF tidal predictions, and the openly available datasets. However, the claim of 'good agreement with theoretical predictions' is weakened by the fact that the PCM simulation is constrained with observed MY36 dust opacity maps rather than being a free-running prediction, and there is an internal inconsistency regarding whether all four dust storms produced inverse tidal phase responses.
major comments (4)
- [§7.2 and Abstract] The statement that the observed 2-4 sol baroclinic wave activity is 'in good agreement with theoretical predictions by model calculations' is overstated. The PCM simulation described in §7.2 is not free-running: it is constrained by MCS- and EMIRS-derived MY36 column opacity maps, and dust is injected whenever the simulated column opacity falls below the observed map value. The simulated growth of wave amplitudes during the dusty season is therefore a radiatively forced response to the observed dust forcing, not an independent theoretical prediction. The abstract and Summary should be rephrased to say 'consistent with a dust-assimilating PCM simulation,' or the authors should add a genuinely free-running simulation (or a sensitivity run with climatological dust) to validate the dust-wave trend independently.
- [Abstract, §8 Summary, and §6.8] There is a direct internal inconsistency about whether all four dust storms produced inverse phase responses. The abstract states that 'Three regional dust storms and one polar storm extending over Jezero produced an increase in the diurnal and semidiurnal amplitudes but resulted in inverse responses in their phases,' and the §8 Summary bullet 'Dust Storms and tides' includes the four storms and states that the semidiurnal phase showed punctual increases during the four storms. However, §6.8 explicitly reports that for DS-NPC 'their phases do not show a change in sols 650-660,' and §6.6 already flagged that 'the case of storm DS-NPC is less obvious.' The abstract and Summary must be revised to exclude DS-NPC from the generalized phase-response statement or to explicitly qualify the exception.
- [§7.2 and §8 Summary, 'Dust Cyclones' bullet] The Summary states that the polar-cap-edge cyclones 'are most probably behind the pressure oscillations detected at Perseverance,' but the body text in §7.2 only offers this as a possibility, noting that if the oscillation were related to the cyclones, the pressure disturbance would need a radius of action 2-3 times larger than the vortex size. The evidence presented is temporal coincidence and distance (1500-4500 km), with no quantitative lag-correlation or composite analysis tying individual cyclone passages to individual pressure oscillations. This causal attribution is load-bearing for the 'Dust Cyclones' summary claim and should either be softened to a hypothesis or supported by a statistical association test between cyclone events and pressure oscillation timings.
- [§5, Figure 3b] The dominant-period claim of 2-4 sols rests on the time separation between consecutive peaks in the detrended pressure series, yielding a mean of 3.8 ± 1.9 sols. This method does not provide a spectral estimate with confidence intervals, and the large scatter makes the 'dominant period' identification fragile. A Lomb-Scargle periodogram or wavelet analysis of the detrended pressure would better support the central period range used to argue for baroclinic waves. If such an analysis is already available from Paper 1's methodology, it should be reported here; otherwise the period distribution should be presented as a descriptive peak-count statistic rather than as a validated dominant period.
minor comments (5)
- [§7.1, Figure 16] The linear relation is printed as '1.6 0.3τ +' in the text; this should read '1.6 + 0.3τ' both in the text and in the figure caption.
- [§4] The sentence 'In general the Martian PCM results reproduce the behavior of the tidal amplitudes reasonably well' is ambiguous because the preceding paragraph compares with the Mars Climate Database and MarsWRF, while the PCM simulation is introduced later in §7.2. Please clarify which model output is shown in Figure 2 and use consistent terminology for MCD, MarsWRF, and PCM.
- [§7.2] The phrase 'two-moment aerosol sizes distributions' should be 'two-moment aerosol size distributions,' and the equation for the baroclinic index is garbled in the typeset text and should be reformatted.
- [References] The reference to 'Laboratoire de Météorology Dynamique' should be 'Laboratoire de Météorologie Dynamique.'
- [§6.4] The sentence 'This is consistent with the high density cloud detection from Ls ∼ 130°-150° by two different Perseverance instruments by Toledo et al. (2023) and Patel et al. (2023)' would read more clearly as 'consistent with the high-density cloud detections from Ls ∼ 130°-150° reported by Toledo et al. (2023) and Patel et al. (2023).'
Circularity Check
The only load-bearing 'prediction' is a dust-constrained PCM simulation; the tide–dust correlations are explicitly empirical, so the observational core is not circular.
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fitted input called prediction
[Abstract and Section 7.2 (Long-period waves, PCM simulation)]
"The simulation has been carried out over multiple annual cycles for MY36 using the available MCS- and EMIRS-derived column opacity maps for that year (Montabone et al., 2023), as a constraint for the simulation to match. In practice, dust is injected from the surface into the PBL when the simulated dust column opacity is lower than that in the column opacity map so that the aerosol and temperature distributions could reach a seasonally equilibrated state."
The abstract's 'good agreement with theoretical predictions by model calculations' and Section 7.2's 'the model reproduces the main trend observed with MEDA' are presented as independent theoretical support, but the simulation is not free-running: it is constrained to the observed MY36 dust column opacity maps, with dust injected whenever the simulated opacity falls below the map. The dusty-season growth of 2–4 sol pressure oscillations is therefore a radiatively forced response to the observed dust field, not an independent prediction from first principles. The agreement is a consistency check with a dust-assimilating simulation; calling it a theoretical prediction makes the model output look like independent confirmation of the very dust–wave trend that was partly put into the model.
full rationale
The observational core—MEDA pressure tides and long-period waves, orbital cyclone tracking, dust storm chronology—is self-contained and does not reduce to its inputs. The tide–dust amplitude relations in Section 7.1 and Figure 16 are explicitly empirical (fitted mixture percentages and the linear 1.6 + 0.3τ relation), so they are not disguised predictions; they are characterizations of the data. The main circularity-adjacent step is the PCM comparison in Section 7.2, where the 'theoretical prediction' is actually a simulation nudged to observed MY36 dust maps, so the wave–dust agreement is partly forced by the input dust. This raises the score but does not invalidate the paper's central observational claims, which stand independently. Separately, there is an internal inconsistency between Section 6.8 ('their phases do not show a change in sols 650-660') and the abstract/Section 8 claim that all four dust storms produced inverse tidal phase responses; this is a correctness issue, not circularity.
Assumptions & free parameters
free parameters (3)
- Tide amplitude mixture percentages =
S1 27%, S2 53%, S3 16%, S4 4% (alternative: 50% S1 + 50% S2)
- Linear amplitude vs opacity relation coefficients =
1.6 and 0.3 (amplitude = 1.6 + 0.3 tau)
- Effective dust particle radius in PCM simulation =
3 micrometers
assumptions (3)
- domain assumption The Lindzen-Farrell baroclinic index with fixed coefficient 0.31 estimates the maximum growth rate of baroclinic disturbances on Mars.
- domain assumption MCD standard climatology and average solar conditions are representative of the temperature and zonal wind fields used to compute the baroclinic index.
- domain assumption Pressure oscillations at Jezero reflect synoptic-scale wave activity rather than local crater effects or instrumental artifacts.
Cite this review
Pith. "Pith review of Martian atmospheric disturbances from orbital images and surface pressure at Jezero Crater, Mars, during Martian Year 36." pith.science (2026). https://pith.science/paper/7IRTLZEX
@misc{pith2026250105337,
author = {Pith},
title = {Pith review of: Martian atmospheric disturbances from orbital images and surface pressure at Jezero Crater, Mars, during Martian Year 36},
year = {2026},
howpublished = {\url{https://pith.science/paper/7IRTLZEX}},
note = {Machine review of arXiv:2501.05337}
}
abstract
We present a study of atmospheric disturbances at Jezero Crater, Mars, using ground-based measurements of surface pressure by the Perseverance rover in combination with orbital images from the Mars Express and Mars Reconnaissance Orbiter missions. The study starts at Ls $\sim$ 13.3{\deg} in MY36 (March 6th, 2021) and extends up to Ls $\sim$ 30.3{\deg} in MY37 (February 28th, 2023). We focus on the characterization of the major atmospheric phenomena at synoptic and planetary-scales. These are the thermal tides (measured up to the sixth component), long-period pressure oscillations (periods > 1 sol), the Aphelion Cloud Belt, and the occasional development of regional dust storms over Jezero. We present the seasonal evolution of the amplitudes and phases of the thermal tides and their relation with the atmospheric dust content (optical depth). Three regional dust storms and one polar storm extending over Jezero produced an increase in the diurnal and semidiurnal amplitudes but resulted in inverse responses in their phases. We show that the primary regular wave activity is due to baroclinic disturbances with periods of 2-4 sols and amplitudes $\sim$ 1-15 Pa increasing with dust content, in good agreement with theoretical predictions by model calculations. The spacecraft images show a number of arc-shaped, spiral and irregular cyclonic vortices, traced by dust and clouds at the edge of the North Polar Cap, that could be behind some of the pressure oscillations measured at Jezero.
Figures
Figures from the paper (2 more)
Reference graph
Works this paper leans on
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Reviewed August 10, 2026 · model on record in the stance chip above.
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