Jupiter’s dense cloud layers often obscure visible flashes, especially from deeper or “stealth” storms. Optical detections (from earlier missions or Juno’s cameras) can underestimate intensity because light is scattered or absorbed.

Microwave signals, however, pass through clouds more effectively, providing a clearer view of the true power released inside these convective towers. This explains why earlier data sometimes suggested more modest strengths, while deeper probing reveals far more extreme events.

Lightning on Jupiter was first confirmed decades ago, but Juno’s close orbits since 2016 have revolutionized our understanding. Unlike Earth—where lightning is most common near the equator over land—Jovian lightning occurs at higher latitudes and is tied to the planet’s rapid rotation, internal heat, and vast scale. These findings help model convection and electricity in hydrogen atmospheres, with potential insights for both planetary science and extreme weather physics on Earth.

The exact upper limits remain an active area of research, as pulse duration and exact energy conversion involve some modeling assumptions. Still, the data clearly show Jupiter hosts electrical discharges on a super-planetary scale.

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Radio Pulse Power Distribution of Lightning in Jupiter’s 2021–2022 Stealth Superstorms

“Radio Pulse Power Distribution of Lightning in Jupiter’s 2021–2022 Stealth Superstorms” is the title of a peer-reviewed paper published on March 20, 2026, in AGU Advances (DOI: 10.1029/2025AV002083), led by Michael H. Wong (UC Berkeley) with co-authors including Ivana Kolmašová and others from the Juno team.

Title: Radio Pulse Power Distribution of Lightning in Jupiter’s 2021–2022 Stealth Superstorms

Authors: Michael H. Wong (lead), Ivana Kolmašová, Fabiano A. Oyafuso, and Juno team co-authors

Published: 20 March 2026 in AGU Advances (open access)

DOI: 10.1029/2025AV002083

peer-reviewed

Abstract

Surveys and observations of lightning on Jupiter prior to the NASA Juno mission used night-side imaging approaches, and a common conclusion was that the optical energy was similar to the highest energy terrestrial lightning flashes, or superbolts. We use data from the Juno Microwave Radiometer (MWR) to measure the first radio pulse power distribution of Jovian lightning. The power distribution measurement was enabled by unique meteorological conditions in Jupiter’s North Equatorial Belt (NEB) in 2021–2022, as the belt transitioned from an anomalously quiescent (non-convective) state to its more typical configuration with small moist convective plumes scattered in longitude. During this transition, convective plumes in the NEB occurred only in isolated storms we label “stealth superstorms.” The isolated nature of these storms (as lightning sources) resolved the degeneracy between pulse location and pulse strength, allowing measurement of a pulse power distribution with statistical median values ranging from 27 to 214 W over the MWR bandpass, well within the observational sensitivity range. The MWR thus measures typical pulse power in the storms, rather than high-power outliers. Pulse power in the stealth superstorms may be comparable to terrestrial lightning radio emission, or up to a million times more powerful, depending on uncertainties in unresolved pulse duration and lightning spectral energy distributions. Future studies may determine whether the lightning pulse power in stealth superstorm is typical or anomalous of Jupiter’s lightning in general.

Previous studies of Jovian lightning (mostly optical night-side imaging from Galileo, Cassini, or Juno) often concluded that Jupiter’s flashes were comparable to Earth’s rare “superbolts.” Those observations were biased toward the brightest events. This paper provides the first statistical radio pulse power distribution for Jupiter lightning, using a unique meteorological window that let the team pin down source locations and thus calculate true source powers (not just received signal strength).

In 2021, Jupiter’s North Equatorial Belt (NEB) went unusually quiet. Convection then re-emerged as isolated, long-lived “stealth superstorms” at a single active longitude (~9.5°N planetocentric). These storms were hard to see in many optical wavelengths (hence “stealth”) but produced strong lightning. Because they were isolated, Juno’s Microwave Radiometer (MWR) could attribute radio pulses to a known storm rather than facing the usual power/location degeneracy.

Data and Methods

• Instrument: Juno MWR Channel 1 (600 MHz / 50 cm wavelength)
• Detection: Lightning appears as brief spikes in brightness temperature, usually spanning one or more 0.1-second integration periods (actual discharge duration is much shorter — milliseconds, per Juno Waves instrument).
• Geometry: Juno flew over the active longitude during four perijoves (PJ38, 39, 44, 47) between September 2021 and December 2022.
• Key innovation: Using spacecraft pointing, antenna gain pattern (21° FWHM beam, but detectable at larger off-boresight angles), and distance to Jupiter, the team computed isotropic radiated source powers for each pulse.

Total detections: 613 radio pulses across the four encounters.
Rate: Average ~3 pulses per second during the storm passes (one pass alone had 206 pulses).

Main Result:

The combined power distribution from all four perijoves is roughly log-normal in shape, with a clear peak (mode) and median that fall comfortably inside the MWR’s sensitivity range.

• Median source powers (over the MWR bandpass) ranged from 27 W to 214 W depending on the specific perijove.
• The distribution shows that MWR was detecting typical Jovian lightning activity, not just rare superbolt outliers.
• Weakest pulses: comparable in radio power to terrestrial lightning.
• Stronger pulses: reach ~100× (or higher) the radio power of typical Earth lightning (after accounting for bandpass differences).
• The peaked shape argues against the idea that earlier observations were dominated by extreme events; Juno was seeing the bulk of the distribution.

Comparison to Earth Lightning

Direct comparison is tricky because:

• MWR measures at 600 MHz.
• Terrestrial datasets (e.g., FORTE satellite or WWLLN) use very different frequency bands (often kHz range).

Using published power-law spectral models (e.g., Oh 1969; Weidman et al. 1981) to extrapolate, the authors conclude that the radio pulse powers in these stealth superstorms are likely in the range of ~1 to 100 times those of terrestrial lightning. Some interpretive upper bounds (depending on spectral assumptions and exact energy metrics) can reach much higher factors, which is why popular articles sometimes cite “up to a million times” in extreme scenarios.Important caveat: MWR’s 0.1 s integration can sum energy from multiple discharges, and the paper focuses on radio pulse power, not total optical/thermal/electromagnetic energy of the bolt.

Key Takeaways (from the paper)

• The isolation of the stealth superstorms broke the power/location degeneracy and enabled the first true source-power distribution.
• Jupiter’s lightning in these storms occurs at a high rate (~3 pulses/s) and spans a wide but statistically peaked power range.
• Microwave observations reveal activity that can be hidden or underestimated in optical data.
• This improves our understanding of charge separation and convection in Jupiter’s ammonia–water–hydrogen atmosphere.

The paper includes supporting data on Dryad (lightning pulse listings from the four perijoves).

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The Spectral extrapolation

Spectral extrapolation is one of the trickiest and most important parts of the 2026 Wong et al. paper. It is required because you cannot directly compare the raw radio powers measured by Juno’s Microwave Radiometer (MWR) at 600 MHz with the vast majority of terrestrial lightning radio datasets, which are recorded at much lower frequencies.

Why Extrapolation Is Needed

• Juno MWR Channel 1 measures lightning as radio pulses at 600 MHz (50 cm wavelength, VHF band).
• Most Earth lightning radio power statistics come from:
  • WWLLN (World Wide Lightning Location Network): primarily 5–18 kHz (VLF/LF).
  • FORTE satellite: different bands, often lower frequencies.
• The frequency gap is enormous — roughly 4–5 orders of magnitude (from ~10 kHz to 600 MHz). Lightning radio emission is not flat across frequencies; its power drops off sharply at higher frequencies according to a power-law spectrum.

Direct numerical comparison of “received power” or “source power” would be meaningless without adjusting for this frequency dependence.

The Terrestrial Spectral Models Used

The paper relies on two classic references for the frequency dependence of terrestrial lightning radio emission:

• Oh (1969) — “Measured and Calculated Spectral Amplitude Distribution of Lightning Sferics” — Provides a broad model spanning ~1 kHz to 10 GHz. It was one of the early attempts to predict the average spectral shape of sferics (lightning radio pulses) over a very wide frequency range.
• Weidman et al. (1981) — “Lightning amplitude spectra in the interval from 100 kHz to 20 MHz” — Gives more detailed, piecewise power-law behavior based on measurements of return strokes:
  • ≈ f⁻¹ (1/f) from ~100 kHz to 2 MHz
  • ≈ f⁻² from 2 MHz to 10 MHz
  • ≈ f⁻⁵ (very steep drop) above 10 MHz

These are amplitude spectra (or spectral density), so power scales with the square of amplitude. The steep fall-off at higher frequencies means that the same physical lightning discharge radiates far less power at 600 MHz than at 10 kHz.

How the Paper Applies Extrapolation

The authors take the modal (peak/typical) power from the terrestrial distributions (WWLLN and FORTE) and use the Oh (1969) and Weidman et al. (1981) spectral shapes to “shift” those values up to 600 MHz. They then compare the extrapolated terrestrial modal power with the actual source powers measured for Jupiter’s stealth superstorm lightning pulses (median values 27–214 W in the MWR bandpass, with some events reaching several megawatts).

Main conclusion from the paper:

“If we use these spectra to extrapolate lightning modal power from WWLLN and FORTE to the 600-MHz frequency of MWR, we find that Jovian lightning is likely to be in the range of 1 to 100 times more powerful than terrestrial lightning.”

This 1–100× range is the most defensible result using the published spectral models.

Depending on the chosen power-law index and these assumptions, the scaling factor can become extremely large — leading to the up to ~10⁶ (one million times) upper-bound numbers that appear in press coverage. The paper itself is more cautious and emphasizes the 1–100× range as the most plausible for typical events.

In short, the spectral extrapolation is the main source of uncertainty in the Earth–Jupiter power comparison. The paper’s core advance (the statistical power distribution from the isolated stealth superstorms) is robust, but translating those 600 MHz powers into an exact “X times stronger than Earth” multiplier remains model-dependent.