The intriguing circumpolar cyclone pattern at Jupiter's poles raises fundamental questions about how these systems are organized vertically and, further, how the planet's internal heat shapes and sustains them in the absence of solar insolation. We report recent close-in observations of Jupiter's north pole acquired by NASA's Juno Microwave Radiometer, which achieved comprehensive microwave mapping of the region at an unprecedentedly high resolution. Using six-channel measurements from 11 perijove passes (PJ51–PJ61) poleward of 75°N, we derive polar-mean nadir brightness temperatures and limb-darkening spectra that together point to two equally plausible atmospheric scenarios: (1) a dry adiabatic profile with slightly depleted ammonia gas at a few bars; or (2) a moist adiabatic profile with uniform ammonia. Markov chain Monte Carlo retrievals yield a deep ammonia abundance of 354.8_(−11.0)^(+12.0) ppmv (∼3 ± 0.1 × solar) and a water abundance of 1.8_(−1.1 + 1.5 × 10³ ppmv (∼2.1_(−1.3)^(+1.8) × solar), resembling previous estimates at lower latitudes. Remarkably, the north pole is found to be 6–7 K warmer than the equator at the 1 bar level, although the inferred difference is close to the 1 σ uncertainty level. If confirmed, this result would suggest an enhanced internal heat flux toward the poles, which is consistent with the more intense lightning activity observed at high latitudes.
", "doi": "10.3847/1538-4357/ae6ef5", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2026-07-20", "series_number": "1", "volume": "1006", "issue": "1", "pages": "94" }, { "id": "authors:qnqdp-hz154", "collection": "authors", "collection_id": "qnqdp-hz154", "cite_using_url": "https://authors.library.caltech.edu/records/qnqdp-hz154", "type": "article", "title": "Structure of Jupiter's High-Latitude Storms: Folded Filamentary Regions Revealed by Juno", "author": [ { "family_name": "Fletcher", "given_name": "L. N.", "orcid": "0000-0001-5834-9588" }, { "family_name": "Zhang", "given_name": "Z.", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" }, { "family_name": "Brown", "given_name": "S.", "orcid": "0000-0002-7566-8537", "clpid": "Brown-Shannon" }, { "family_name": "Oyafuso", "given_name": "F. A.", "orcid": "0000-0002-8862-8737", "clpid": "Oyafuso-Fabiano-A" }, { "family_name": "Rogers", "given_name": "J. H.", "orcid": "0000-0002-4239-5907" }, { "family_name": "Wong", "given_name": "M. H.", "orcid": "0000-0003-2804-5086" }, { "family_name": "Mura", "given_name": "A.", "orcid": "0000-0002-4552-4292" }, { "family_name": "Eichst\u00e4dt", "given_name": "G." }, { "family_name": "Orton", "given_name": "G. S.", "orcid": "0000-0001-7871-2823", "clpid": "Orton-Glenn-S" }, { "family_name": "Brueshaber", "given_name": "S." }, { "family_name": "Sankar", "given_name": "R.", "orcid": "0000-0002-6794-7587" }, { "family_name": "Li", "given_name": "C." }, { "family_name": "Levin", "given_name": "S. M.", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Biagiotti", "given_name": "F." }, { "family_name": "Guillot", "given_name": "T.", "orcid": "0000-0002-7188-8428" }, { "family_name": "Ingersoll", "given_name": "A. P.", "orcid": "0000-0002-2035-9198", "clpid": "Ingersoll-A-P" }, { "family_name": "Grassi", "given_name": "D." }, { "family_name": "Hansen", "given_name": "C. J.", "orcid": "0000-0001-5863-299X" }, { "family_name": "Bolton", "given_name": "S.", "orcid": "0000-0002-9115-0789" }, { "family_name": "Waite", "given_name": "J. H.", "orcid": "0000-0002-1978-1025" } ], "abstract": "Sprawling, turbulent cloud formations dominate the meteorology of Jupiter's mid-to-high latitudes, known as Folded Filamentary Regions (FFRs). A multi-wavelength characterization by Juno reveals the spatial distribution, vertical structure, and energetics of the FFRs. The cloud tops display multiple lobes of stratiform aerosols, separated by darker, cloud-free lanes, and embedded with smaller eddies and high-altitude cumulus clouds. These cyclonic FFRs are microwave-bright in shallow-sounding wavelengths (p < 5 bars) and microwave-dark in deep-sounding wavelengths (p > 10 bars), with the transition potentially associated with the water condensation layer (6–7 bars). Associating microwave contrasts with temperature anomalies, this implies despinning of cyclonic eddies above/below their mid-planes. Despite deep roots (being detectable in wavelengths sounding ~ 100 bars), they are “pancake vortices” with horizontal extents at least an order of magnitude larger than their depth. In the northern hemisphere, FFRs are most common in cyclonic belts poleward of 40° N (all latitudes are planetocentric), particularly a North Polar Filamentary Belt (NPFB) near 66 – 70 °N that defines the transition from organized belts/zones to the chaotic polar domain. This distribution explains the high lightning rates from 45 - 80° N, peaking in a belt poleward of 52.3° N, which may trace the availability of water for moist convection. Many observed lightning flashes can be associated to specific FFRs containing bright storms, but some FFRs display no activity, suggesting quiescent periods during storm evolution. Analogies to Earth's oceanic eddies suggest that cyclones deform isentropic surfaces at their midplanes, raising deep water-rich layers upwards to promote moist convection, release latent heat, and inject clouds into the upper troposphere.
", "doi": "10.1029/2025je009315", "issn": "2169-9097", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research: Planets", "publication_date": "2026-01", "series_number": "1", "volume": "131", "issue": "1", "pages": "e2025JE009315" }, { "id": "authors:c3qfr-pk532", "collection": "authors", "collection_id": "c3qfr-pk532", "cite_using_url": "https://authors.library.caltech.edu/records/c3qfr-pk532", "type": "article", "title": "Europa's ice thickness and subsurface structure characterized by the Juno microwave radiometer", "author": [ { "family_name": "Levin", "given_name": "S. M.", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Zhang", "given_name": "Z.", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" }, { "family_name": "Bolton", "given_name": "S. J." }, { "family_name": "Brown", "given_name": "S." }, { "family_name": "Ermakov", "given_name": "A. I.", "orcid": "0000-0002-7020-7061" }, { "family_name": "Feng", "given_name": "J.", "orcid": "0000-0001-9904-3569" }, { "family_name": "Hand", "given_name": "K.", "orcid": "0000-0002-3225-9426", "clpid": "Hand-Kevin" }, { "family_name": "Misra", "given_name": "S.", "orcid": "0000-0003-1738-6635", "clpid": "Misra-Sidharth" }, { "family_name": "Siegler", "given_name": "M." }, { "family_name": "Stevenson", "given_name": "D.", "orcid": "0000-0001-9432-7159", "clpid": "Stevenson-D-J" }, { "family_name": "McKinnon", "given_name": "W." }, { "family_name": "Akiba", "given_name": "R.", "orcid": "0000-0002-2681-3195" } ], "abstract": "Jupiter’s moon Europa is thought to harbour a saltwater ocean beneath a variously disrupted ice shell, and it is, thus, one of the highest priority astrobiology targets in the Solar System. Estimates of the ice-shell thickness range from 3 km to over 30 km, and observations by the Galileo spacecraft indicated widespread regions of ice disruption (chaotic terrain) leading to speculation that the ice shell may contain subsurface cracks, faults, pores or bubbles. If persistent, subsurface cracks could provide pathways for habitability by facilitating the transport of oxygen and nutrients between the surface and the ocean. Here we report on observations of Europa’s subsurface ice shell obtained by the Juno microwave radiometer in 2022. For the idealized case of pure water ice, the data are consistent with the existence of a thermally conductive ice shell with a thickness of 29 ± 10 km and with the presence of cracks, pores or other scatterers extending to depths of hundreds of metres below the surface with a characteristic size smaller than a few centimetres in radius. An ice-shell salinity of 15 mg kg−1, as indicated by models based on terrestrial marine ice, would reduce our estimate of the thickness of the ice shell by about 5 km, substantially less than our 10 km uncertainty. The low volume fraction, small size and shallow depth of the scatterers indicate that the fracture interfaces observed at Europa’s surface are alone unlikely to be capable of carrying nutrients between the surface and the ocean.
\nThunderstorms play a significant role in transporting heat from the deep interior to space on giant planets. We present observations of a 3,400-km wide thunderstorm complex in Jupiter’s North Equatorial Belt (NEB) during the 38th periapse of the Juno spacecraft on 29 Nov. 2021. Data were acquired by the Microwave Radiometer (MWR), the visible light JunoCam instrument, the Jovian InfraRed Auroral Mapper (JIRAM), and from supporting Earth-based imaging. This was the first time Juno was able to observe a thunderstorm at suitably low emission angles with multiple instruments at close range (∼5,690 km), making it the most comprehensive close-up assessment of a Jovian thunderstorm to date. Lightning detection confirmed the Storm’s vigorous convective nature. MWR brightness temperatures indicate this Storm appears to be wholly contained within the weather layer, i.e., no deeper than the expected base of the H\u2082O cloud, and not as a result of any detected deep-seated upwelling beneath the H\u2082O cloud base. Earth-based observations tracked it over its ∼ 2-week lifespan, providing evidence that mesoscale-to-synoptic-scale forcing mechanisms were involved in sustaining it, including the intriguing possibility of a humidity front (‘dryline’), a sharp gradient in the vapor abundance, promoting lift along a concentrated region.
", "doi": "10.1016/j.icarus.2025.116465", "issn": "0019-1035", "publisher": "Elsevier", "publication": "Icarus", "publication_date": "2025-05-15", "volume": "432", "pages": "116465" }, { "id": "authors:xjqdc-y0688", "collection": "authors", "collection_id": "xjqdc-y0688", "cite_using_url": "https://authors.library.caltech.edu/records/xjqdc-y0688", "type": "article", "title": "Long-lasting, deep effect of Saturn's giant storms", "author": [ { "family_name": "Li", "given_name": "Cheng", "orcid": "0000-0002-8280-3119", "clpid": "Li-Cheng" }, { "family_name": "de Pater", "given_name": "Imke", "orcid": "0000-0002-4278-3168", "clpid": "de-Pater-Imke" }, { "family_name": "Moeckel", "given_name": "Chris", "orcid": "0000-0002-6293-1797", "clpid": "Moeckel-Chris" }, { "family_name": "Sault", "given_name": "R. J.", "orcid": "0000-0001-9209-7716", "clpid": "Sault-Robert-J" }, { "family_name": "Butler", "given_name": "Bryan", "orcid": "0000-0002-5344-820X", "clpid": "Butler-Bryan" }, { "family_name": "deBoer", "given_name": "David", "orcid": "0000-0003-3197-2294", "clpid": "deBoer-David" }, { "family_name": "Zhang", "given_name": "Zhimeng", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" } ], "abstract": "Planetary-scale giant storms erupt on Saturn quasiperiodically. There have been at least six recorded occurrences of past eruptions, and the most recent one was in 2010, with its whole life span captured by the Cassini mission. In 2015, we used the Very Large Array to probe the deep response of Saturn's troposphere to the giant storms. In addition to the remnant effect of the storm in 2010, we have found long-lasting signatures of all mid-latitude giant storms, a mixture of equatorial storms up to hundreds of years old, and potentially an unreported older storm at 70\u00b0N. We derive an ammonia anomaly map that shows an extended meridional migration of the storm's aftermath and vertical transport of ammonia vapor by storm dynamics. Intriguingly, the last storm in 2010 splits into two distinct components that propagate in opposite meridional directions, leaving a gap at 43\u00b0N planetographic latitude.", "doi": "10.1126/sciadv.adg9419", "pmcid": "PMC10421028", "issn": "2375-2548", "publisher": "American Association for the Advancement of Science", "publication": "Science Advances", "publication_date": "2023-08-11", "series_number": "32", "volume": "9", "issue": "32", "pages": "eadg9419" }, { "id": "authors:zhpmg-mpz61", "collection": "authors", "collection_id": "zhpmg-mpz61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211103-145253753", "type": "article", "title": "Microwave observations reveal the deep extent and structure of Jupiter's atmospheric vortices", "author": [ { "family_name": "Bolton", "given_name": "S. J.", "orcid": "0000-0002-9115-0789", "clpid": "Bolton-Scott-J" }, { "family_name": "Levin", "given_name": "S. M.", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Guillot", "given_name": "T.", "orcid": "0000-0002-7188-8428" }, { "family_name": "Li", "given_name": "C.", "orcid": "0000-0002-8280-3119" }, { "family_name": "Kaspi", "given_name": "Y.", "orcid": "0000-0003-4089-0020" }, { "family_name": "Orton", "given_name": "G.", "orcid": "0000-0001-7871-2823", "clpid": "Orton-Glenn-S" }, { "family_name": "Wong", "given_name": "M. H.", "orcid": "0000-0003-2804-5086" }, { "family_name": "Oyafuso", "given_name": "F.", "orcid": "0000-0002-8862-8737", "clpid": "Oyafuso-Fabiano-A" }, { "family_name": "Allison", "given_name": "M.", "orcid": "0000-0001-9841-193X" }, { "family_name": "Arballo", "given_name": "J.", "orcid": "0000-0002-4487-4274", "clpid": "Arballo-John" }, { "family_name": "Atreya", "given_name": "S.", "orcid": "0000-0002-1972-1815" }, { "family_name": "Becker", "given_name": "H. N.", "orcid": "0000-0001-5777-9850", "clpid": "Becker-Heidi-N" }, { "family_name": "Bloxham", "given_name": "J.", "orcid": "0000-0001-8556-2675" }, { "family_name": "Brown", "given_name": "S. T.", "orcid": "0000-0002-7566-8537", "clpid": "Brown-Shannon-T" }, { "family_name": "Fletcher", "given_name": "L. N.", "orcid": "0000-0001-5834-9588" }, { "family_name": "Galanti", "given_name": "E.", "orcid": "0000-0002-5440-8779" }, { "family_name": "Gulkis", "given_name": "S.", "orcid": "0000-0002-4480-3628", "clpid": "Gulkis-Samuel" }, { "family_name": "Janssen", "given_name": "M.", "orcid": "0000-0001-5476-731X", "clpid": "Janssen-Michael-A" }, { "family_name": "Ingersoll", "given_name": "A.", "orcid": "0000-0002-2035-9198", "clpid": "Ingersoll-A-P" }, { "family_name": "Lunine", "given_name": "J. L.", "orcid": "0000-0003-2279-4131", "clpid": "Lunine-Jonathan-Irving" }, { "family_name": "Misra", "given_name": "S.", "orcid": "0000-0003-1738-6635", "clpid": "Misra-Sidharth" }, { "family_name": "Steffes", "given_name": "P.", "orcid": "0000-0003-3962-8957" }, { "family_name": "Stevenson", "given_name": "D.", "orcid": "0000-0001-9432-7159", "clpid": "Stevenson-D-J" }, { "family_name": "Waite", "given_name": "J. H.", "orcid": "0000-0002-1978-1025" }, { "family_name": "Yadav", "given_name": "R. K.", "orcid": "0000-0002-9569-2438" }, { "family_name": "Zhang", "given_name": "Z.", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" } ], "abstract": "Jupiter's atmosphere has a system of zones and belts punctuated by small and large vortices, the largest being the Great Red Spot. How these features change with depth is unknown, with theories of their structure ranging from shallow meteorological features to surface expressions of deep-seated convection. We present observations of atmospheric vortices using the Juno spacecraft's Microwave Radiometer. We found vortex roots that extend deeper than the altitude at which water is expected to condense, and we identified density inversion layers. Our results constrain the three-dimensional structure of Jupiter's vortices and their extension below the clouds.", "doi": "10.1126/science.abf1015", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2021-11-19", "series_number": "6570", "volume": "374", "issue": "6570", "pages": "968-972" }, { "id": "authors:ff2pm-gkf96", "collection": "authors", "collection_id": "ff2pm-gkf96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210301-102111253", "type": "article", "title": "Jupiter's Temperate Belt/Zone Contrasts Revealed at Depth by Juno Microwave Observations", "author": [ { "family_name": "Fletcher", "given_name": "L. N.", "orcid": "0000-0001-5834-9588", "clpid": "Fletcher-Leigh-N" }, { "family_name": "Oyafuso", "given_name": "F. A.", "orcid": "0000-0002-8862-8737", "clpid": "Oyafuso-Fabiano-A" }, { "family_name": "Allison", "given_name": "M.", "orcid": "0000-0001-9841-193X", "clpid": "Allison-Michael-D" }, { "family_name": "Ingersoll", "given_name": "A.", "orcid": "0000-0002-2035-9198", "clpid": "Ingersoll-A-P" }, { "family_name": "Li", "given_name": "L.", "orcid": "0000-0002-5257-9849", "clpid": "Li-Liming" }, { "family_name": "Kaspi", "given_name": "Y.", "orcid": "0000-0003-4089-0020", "clpid": "Kaspi-Yohai" }, { "family_name": "Galanti", "given_name": "E.", "orcid": "0000-0002-5440-8779", "clpid": "Galanti-Eli" }, { "family_name": "Wong", "given_name": "M. H.", "clpid": "Wong-Mike-H" }, { "family_name": "Orton", "given_name": "G. S.", "orcid": "0000-0001-7871-2823", "clpid": "Orton-Glenn-S" }, { "family_name": "Duer", "given_name": "K.", "clpid": "Duer-Keren" }, { "family_name": "Zhang", "given_name": "Z.", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" }, { "family_name": "Li", "given_name": "C.", "orcid": "0000-0002-8280-3119", "clpid": "Li-Cheng-CIT-Planetary Sciences" }, { "family_name": "Guillot", "given_name": "T.", "orcid": "0000-0002-7188-8428", "clpid": "Guillot-Tristan" }, { "family_name": "Levin", "given_name": "S. M.", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Bolton", "given_name": "S.", "orcid": "0000-0002-9115-0789", "clpid": "Bolton-Scott-J" } ], "abstract": "Juno microwave radiometer (MWR) observations of Jupiter's midlatitudes reveal a strong correlation between brightness temperature contrasts and zonal winds, confirming that the banded structure extends throughout the troposphere. However, the microwave brightness gradient is observed to change sign with depth: the belts are microwave-bright in the p < 5 bar range and microwave-dark in the p > 10 bar range. The transition level (which we call the \"jovicline\") is evident in the MWR 11.5 cm channel, which samples the 5\u201314 bar range when using the limb-darkening at all emission angles. The transition is located between 4 and 10 bars, and implies that belts change with depth from being NH\u2083-depleted to NH\u2083-enriched, or from physically warm to physically cool, or more likely a combination of both. The change in character occurs near the statically stable layer associated with water condensation. The implications of the transition are discussed in terms of ammonia redistribution via meridional circulation cells with opposing flows above and below the water condensation layer, and in terms of the \"mushball\" precipitation model, which predicts steeper vertical ammonia gradients in the belts versus the zones. We show via the moist thermal wind equation that both the temperature and ammonia interpretations can lead to vertical shear on the zonal winds, but the shear is ~50 x weaker if only NH\u2083 gradients are considered. Conversely, if MWR observations are associated with kinetic temperature gradients then it would produce zonal winds that increase in strength down to the \"jovicline\", consistent with Galileo probe measurements; then decay slowly at higher pressures.", "doi": "10.1029/2021JE006858", "issn": "2169-9097", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research: Planets", "publication_date": "2021-10", "series_number": "10", "volume": "126", "issue": "10", "pages": "Art. No. e2021JE006858" }, { "id": "authors:4berb-c9p05", "collection": "authors", "collection_id": "4berb-c9p05", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200818-104028139", "type": "article", "title": "Residual Study: Testing Jupiter Atmosphere Models Against Juno MWR Observations", "author": [ { "family_name": "Zhang", "given_name": "Zhimeng", "orcid": "0000-0002-1558-4948", "clpid": "Zhang-Zhimeng" }, { "family_name": "Adumitroaie", "given_name": "Virgil", "orcid": "0000-0001-7239-0069", "clpid": "Adumitroaie-Virgil" }, { "family_name": "Allison", "given_name": "Michael", "orcid": "0000-0001-9841-193X", "clpid": "Allison-Michael" }, { "family_name": "Arballo", "given_name": "John", "clpid": "Arballo-John" }, { "family_name": "Atreya", "given_name": "Sushil", "orcid": "0000-0002-1972-1815", "clpid": "Atreya-Sushil-K" }, { "family_name": "Bjoraker", "given_name": "Gordon", "clpid": "Bjoraker-Gordon" }, { "family_name": "Bolton", "given_name": "Scott", "orcid": "0000-0002-9115-0789", "clpid": "Bolton-Scott-J" }, { "family_name": "Brown", "given_name": "Shannon", "orcid": "0000-0002-7566-8537", "clpid": "Brown-Shannon-T" }, { "family_name": "Fletcher", "given_name": "Leigh N.", "orcid": "0000-0001-5834-9588", "clpid": "Fletcher-Leigh-N" }, { "family_name": "Guillot", "given_name": "Tristan", "orcid": "0000-0002-7188-8428", "clpid": "Guillot-Tristan" }, { "family_name": "Gulkis", "given_name": "Samuel", "orcid": "0000-0002-4480-3628", "clpid": "Gulkis-Samuel" }, { "family_name": "Hodges", "given_name": "Amoree", "orcid": "0000-0002-4894-5826", "clpid": "Hodges-Amoree" }, { "family_name": "Ingersoll", "given_name": "Andrew", "orcid": "0000-0002-2035-9198", "clpid": "Ingersoll-A-P" }, { "family_name": "Janssen", "given_name": "Michael", "orcid": "0000-0001-5476-731X", "clpid": "Janssen-Michael-A" }, { "family_name": "Levin", "given_name": "Steven", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Li", "given_name": "Cheng", "orcid": "0000-0002-8280-3119", "clpid": "Li-Cheng-CIT-Planetary Sciences" }, { "family_name": "Li", "given_name": "Liming", "orcid": "0000-0002-5257-9849", "clpid": "Li-Liming" }, { "family_name": "Lunine", "given_name": "Jonathan I.", "orcid": "0000-0003-2279-4131", "clpid": "Lunine-Jonathan-Irving" }, { "family_name": "Misra", "given_name": "Sidharth", "orcid": "0000-0003-1738-6635", "clpid": "Misra-Sidharth" }, { "family_name": "Orton", "given_name": "Glenn", "orcid": "0000-0001-7871-2823", "clpid": "Orton-Glenn-S" }, { "family_name": "Oyafuso", "given_name": "Fabiano", "orcid": "0000-0002-8862-8737", "clpid": "Oyafuso-Fabiano-A" }, { "family_name": "Steffes", "given_name": "Paul", "orcid": "0000-0003-3962-8957", "clpid": "Steffes-Paul-G" }, { "family_name": "Wong", "given_name": "Michael H.", "orcid": "0000-0003-2804-5086", "clpid": "Wong-Michael-H" } ], "abstract": "The Juno spacecraft provides unique close\u2010up views of Jupiter underneath the synchrotron radiation belts while circling Jupiter in its 53\u2010day orbits. The microwave radiometer (MWR) onboard measures Jupiter thermal radiation at wavelengths between 1.37 and 50 cm, penetrating the atmosphere to a pressure of a few hundred bars and greater. The mission provides the first measurements of Jupiter's deep atmosphere, down to ~250 bars in pressure, constraining the vertical distributions of its kinetic temperature and constituents. As a result, vertical structure models of Jupiter's atmosphere may now be tested by comparison with MWR data. Taking into account the MWR beam patterns and observation geometries, we test several published Jupiter atmospheric models against MWR data. Our residual analysis confirms Li et al.'s (2017, https://doi.org/10.1002/2017GL073159) result that ammonia depletion persists down to 50\u201360 bars where ground\u2010based Very Large Array was not able to observe. We also present an extension of the study that iteratively improves the input model and generates Jupiter brightness temperature maps which best match the MWR data. A feature of Juno's north\u2010to\u2010south scanning approach is that latitudinal structure is more easily obtained than longitudinal, and the creation of optimum two\u2010dimensional maps is addressed in this approach.", "doi": "10.1029/2020ea001229", "issn": "2333-5084", "publisher": "American Geophysical Union", "publication": "Earth and Space Science", "publication_date": "2020-09", "series_number": "9", "volume": "7", "issue": "9", "pages": "Art. No. e2020EA001229" }, { "id": "authors:yjh1m-kjz33", "collection": "authors", "collection_id": "yjh1m-kjz33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191223-105236594", "type": "article", "title": "The water abundance in Jupiter's equatorial zone", "author": [ { "family_name": "Li", "given_name": "Cheng", "orcid": "0000-0002-8280-3119", "clpid": "Li-Cheng" }, { "family_name": "Ingersoll", "given_name": "Andrew", "orcid": "0000-0002-2035-9198", "clpid": "Ingersoll-A-P" }, { "family_name": "Bolton", "given_name": "Scott", "orcid": "0000-0002-9115-0789", "clpid": "Bolton-Scott-J" }, { "family_name": "Levin", "given_name": "Steven", "orcid": "0000-0003-2242-5459", "clpid": "Levin-Steven-M" }, { "family_name": "Janssen", "given_name": "Michael", "orcid": "0000-0001-5476-731X", "clpid": "Janssen-Michael-A" }, { "family_name": "Atreya", "given_name": "Sushil", "orcid": "0000-0002-1972-1815", "clpid": "Atreya-Sushil-K" }, { "family_name": "Lunine", "given_name": "Jonathan", "orcid": "0000-0003-2279-4131", "clpid": "Lunine-Jonathan-Irving" }, { "family_name": "Steffes", "given_name": "Paul", "orcid": "0000-0003-3962-8957", "clpid": "Steffes-Paul-G" }, { "family_name": "Brown", "given_name": "Shannon", "orcid": "0000-0002-7566-8537", "clpid": "Brown-Shannon-T" }, { "family_name": "Guillot", "given_name": "Tristan", "orcid": "0000-0002-7188-8428", "clpid": "Guillot-Tristan" }, { "family_name": "Allison", "given_name": "Michael", "orcid": "0000-0001-9841-193X", "clpid": "Allison-Michael" }, { "family_name": "Arballo", "given_name": "John", "clpid": "Arballo-John" }, { "family_name": "Bellotti", "given_name": "Amadeo", "orcid": "0000-0003-2867-4173", "clpid": "Bellotti-Amadeo-A" }, { "family_name": "Adumitroaie", "given_name": "Virgil", "orcid": "0000-0001-7239-0069", "clpid": "Adumitroaie-Virgil" }, { "family_name": "Gulkis", "given_name": "Samuel", "orcid": "0000-0002-4480-3628", "clpid": "Gulkis-Samuel" }, { "family_name": "Hodges", "given_name": "Andrew", "clpid": "Hodges-Andrew" }, { "family_name": "Li", "given_name": "Liming", "orcid": "0000-0002-5257-9849", "clpid": "Li-Liming" }, { "family_name": "Misra", "given_name": "Sidharth", "orcid": "0000-0003-1738-6635", "clpid": "Misra-Sidharth" }, { "family_name": "Orton", "given_name": "Glenn", "orcid": "0000-0001-7871-2823", "clpid": "Orton-Glenn-S" }, { "family_name": "Oyafuso", "given_name": "Fabiano", "orcid": "0000-0002-8862-8737", "clpid": "Oyafuso-Fabiano-A" }, { "family_name": "Santos-Costa", "given_name": "Daniel", "clpid": "Santos-Costa-Daniel" }, { "family_name": "Waite", "given_name": "Hunter", "clpid": "Waite-Hunter" }, { "family_name": "Zhang", "given_name": "Zhimeng", "clpid": "Zhang-Zhimeng" } ], "abstract": "Oxygen is the most common element after hydrogen and helium in Jupiter's atmosphere, and may have been the primary condensable (as water ice) in the protoplanetary disk. Prior to the Juno mission, in situ measurements of Jupiter's water abundance were obtained from the Galileo probe, which dropped into a meteorologically anomalous site. The findings of the Galileo probe were inconclusive because the concentration of water was still increasing when the probe ceased sending data. Here we report on the water abundance in the equatorial region (0 to 4 degrees north latitude), based on data taken at 1.25 to 22\u2009GHz from the Juno microwave radiometer, probing pressures of approximately 0.7 to 30 bar. Because Juno discovered the deep atmosphere to be surprisingly variable as a function of latitude, it remains to confirm whether the equatorial abundance represents Jupiter's global water abundance. The water abundance at the equatorial region is inferred to be 2.5^(+2.2)_(\u22121.6) ppm, or 2.7^(+2.4_(\u22121.7) times the elemental ratio of protosolar oxygen to hydrogen (1\u03c3 uncertainties). If this reflects the global water abundance, the result suggests that the planetesimals that formed Jupiter were unlikely to have been water-rich clathrate hydrates.", "doi": "10.1038/s41550-020-1009-3", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2020-06", "series_number": "6", "volume": "4", "issue": "6", "pages": "609-616" }, { "id": "authors:j31kv-2p439", "collection": "authors", "collection_id": "j31kv-2p439", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181129-110052269", "type": "article", "title": "VLA multi-wavelength microwave observations of Saturn's C and B rings", "author": [ { "family_name": "Zhang", "given_name": "Z.", "clpid": "Zhang-Zhimeng" }, { "family_name": "Hayes", "given_name": "A. G.", "clpid": "Hayes-A-G" }, { "family_name": "de Pater", "given_name": "I.", "orcid": "0000-0002-4278-3168", "clpid": "de-Pater-I" }, { "family_name": "Dunn", "given_name": "D. E.", "clpid": "Dunn-D-E" }, { "family_name": "Janssen", "given_name": "M. A.", "orcid": "0000-0001-5476-731X", "clpid": "Janssen-M-A" }, { "family_name": "Nicholson", "given_name": "P. D.", "orcid": "0000-0003-2275-4463", "clpid": "Nicholson-P-D" }, { "family_name": "Cuzzi", "given_name": "J. N.", "clpid": "Cuzzi-J-N" }, { "family_name": "Butler", "given_name": "B. J.", "orcid": "0000-0002-5344-820X", "clpid": "Butler-B-J" }, { "family_name": "Sault", "given_name": "R. J.", "orcid": "0000-0001-9209-7716", "clpid": "Sault-R-J" }, { "family_name": "Chatterjee", "given_name": "S.", "orcid": "0000-0002-2878-1502", "clpid": "Chatterjee-S" } ], "abstract": "We present multi-wavelength VLA observations in the microwave of Saturn's rings. The data were obtained over two observational windows and cover a range from the Q to S bands (0.7\u201313\u202fcm). Key ring particle properties are determined in the C and B rings such as particle porosity and non-icy material fraction in order to compare them directly with previously derived results using the 2-cm Cassini RADAR radiometry data (Zhang et al., 2017a, b). We confirm that these new data are consistent with the particles in the C ring being quite porous with porosity values of roughly 75\u201390% depending on different scattering phase functions, as well as the presence of a \"hot band\" in the middle C ring which is associated with both an anomalously high non-icy material fraction and low opacity relative to the rest of the C ring. Furthermore, with our multi-wavelength study we find that the amount of intrinsic thermal emission is almost constant with wavelength, which is unexpected since particles tend to become more absorbing at higher frequencies. If we assume that the non-icy material in the rings is intramixed within the ring particles, this result suggests a corresponding decrease in the imaginary part of the non-icy material dielectric constant at higher frequencies, which is most noticeable in the middle C ring. We do not see evidence for such decrease in the B ring particles. If true, this supports the idea that the non-icy material in the middle C ring has a different origin, and that the larger particles in the middle C ring may be composed of a rocky core covered by a porous, icy mantle. If the non-icy materials in the middle C ring are embedded as large chunks, a core-mantle model for the ring particles there naturally explains this almost constant intrinsic thermal emission. Furthermore, because the VLA has more complete azimuthal angle coverage than the Cassini radiometry observations, we are able to investigate the ring brightness in more detail. In particular, we notice a flatter scattering profile than that predicted by using a pure Mie phase function at higher frequencies (Q and K bands; 0.7\u20131.3\u202fcm) for azimuthal angles between |40|o and |60|o. We can match the observed scattering profile better by introducing a semi-empirical phase function for large particles to account for nonsphericity effects. Finally, the non-icy material fraction in the B ring is less than 1%, which is in agreement with that derived from Cassini observations. The frequency-dependence of the B ring thermal emission sets the lower limit of B ring particle porosity. We confirm that the B ring particles are likely over 80% porous, which at the same time explains the high opacity in the B ring as measured from density waves. Because we are limited by the signal-to-noise ratio, the optical depth of the middle B ring could be higher than the currently accepted values. However, we found that even if the middle B ring is six times more optically thick than the value measured from UVIS occultations, the surface mass density is still likely to be less than 300\u202fg/cm^2, while the exposure time to non-icy pollutants due to micrometeoroid bombardment is less than 200\u202fMyr.", "doi": "10.1016/j.icarus.2018.08.014", "issn": "0019-1035", "publisher": "Elsevier", "publication": "Icarus", "publication_date": "2019-01-01", "volume": "317", "pages": "518-548" } ]