2026
| Title: | Juno Microwave Radiometer Observations Reveal a Warmer Polar Atmosphere on Jupiter |
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| Authors: | Hu, Jiheng; Li, Cheng; Atreya, Sushil K.; Fletcher, Leigh N.; Galanti, Eli; Guillot, Tristan; Kaspi, Yohai; Li, Liming; Lian, Yuan; Mura, Alessandro; Orton, Glenn S.; Oyafuso, Fabiano A.; Smirnova, Maria; Waite, J. Hunter; Wong, Michael H.; Zhang, Zhimeng; Levin, Steven M.; Bolton, Scott J. |
| Affiliation: | AA(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA), AB(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA), AC(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA), AD(School of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK), AE(Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel), AF(Université Côte d'Azur, OCA, Lagrange CNRS, 06304 Nice, France), AG(Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel), AH(Department of Physics, University of Houston, Houston, TX 77204, USA), AI(Aeolis Research, Chandler, AZ 85286, USA), AJ(INAF-Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, 00133, Roma, Italy), AK(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AL(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AM(Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel), AN(Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL 35487, USA), AO(Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA; Carl Sagan Center for Science, SETI Institute, Mountain View, CA 94043, USA), AP(Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA), AQ(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AR(Southwest Research Institute, San Antonio, TX 78238, USA) |
| Journal: | The Astrophysical Journal, Volume 1006, Issue 1, id.94, 18 pp. |
| Publication Date: | Jul 2026 |
| Origin: | American Astronomical Society |
| Keywords: | Jupiter, Flyby missions, Atmospheric composition, Atmospheric structure, Water vapor, Microwave spectroscopy, 873, 545, 2120, 2309, 1791, 2251, Earth and Planetary Astrophysics |
| Abstract Copyright: | © 2026. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/1538-4357/ae6ef5 |
| Bibliographic Code: | 2026ApJ..1006...94H |
| Abstract: | 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 <inline-formula> <mml:math><mml:mn>354</mml:mn><mml:mo>.</mml:mo><mml:msubsup><mml:mrow><mml:mn>8</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>11.0</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>12.0</mml:mn></mml:mrow></mml:msubsup></mml:math> </inline-formula> ppmv (∼3 ± 0.1 × solar) and a water abundance of <inline-formula> <mml:math><mml:mn>1</mml:mn><mml:mo>.</mml:mo><mml:msubsup><mml:mrow><mml:mn>8</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>1.1</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>1.5</mml:mn></mml:mrow></mml:msubsup><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math> </inline-formula> ppmv (<inline-formula> <mml:math><mml:mo>∼</mml:mo><mml:mn>2</mml:mn><mml:mo>.</mml:mo><mml:msubsup><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>1.3</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>1.8</mml:mn></mml:mrow></mml:msubsup><mml:mo>×</mml:mo></mml:math> </inline-formula>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 1σ 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. |
| Title: | The effect of thermo-tidal winds on the expansion of local and regional dust storms on Mars |
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| Authors: | Toigo, Anthony D.; Richardson, Mark I.; Wang, Huiqun |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, USA), AB(Aeolis Research, USA), AC(Smithsonian Astrophysical Observatory, Harvard-Smithsonian Center for Astrophysics, USA) |
| Journal: | Icarus, Volume 450, id.116975. |
| Publication Date: | May 2026 |
| Origin: | Elsevier BV |
| Abstract Copyright: | © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| DOI: | https://doi.org/10.1016/j.icarus.2026.116975 |
| Bibliographic Code: | 2026Icar..45016975T |
| Abstract: | Recent imaging observations from the Emirates Exploration Imager show significant diurnal variation of dust storm evolution that is unresolved by traditional daily global mapping from sun synchronous orbit. Motivated by these observations, we present initial simulations from a global numerical model examining the diurnal evolution of transported, radiatively active dust from simulated dust sources. The simulations show that the expansion and mixing of large local and regional dust storms are strongly modified by the wide diurnal "reach" of thermo-tidal winds. In particular, thermo-tidal winds can rapidly spread dust between adjacent storms and can translate storms over significant distances, including transporting storm dust between different meteorological regimes. |
| Title: | The Dissipation Regime of Turbulence on Mars Observed With Microphone Data From the Mars 2020 Perseverance Rover |
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| Authors: | Stott, Alexander E.; Murdoch, Naomi; Gillier, Martin; Martinez, German; Bertrand, Tanguy; Lorenz, Ralph; Newman, Claire; Hueso, Ricardo; de la Torre Juárez, Manuel; Banfield, Donald; Maurice, Sylvestre; Chide, Baptiste; Rodriguez Manfredi, Jose Antonio; Mimoun, David |
| Affiliation: | AA(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France;), AB(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France;), AC(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France;), AD(Centro de Astrobiologia (CAB), CSIC-INTA, Madrid, Spain), AE(Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA), Observatoire de Paris-PSL, CNRS, Sorbonne Université, Université de Paris Cité, Meudon, France;), AF(Johns Hopkins Applied Physics Lab, Laurel, MD, USA;), AG(Aeolis Research, Chandler, AZ, USA;), AH(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain;), AI(Jet Propulsion Laboratory—California Institute of Technology, Pasadena, CA, USA;), AJ(NASA Ames, Mountain View, CA, USA), AK(Institut de Recherche en Astrophysique et Planétologie (IRAP), Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France), AL(Institut de Recherche en Astrophysique et Planétologie (IRAP), Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France;), AM(Centro de Astrobiologia (CAB), CSIC-INTA, Madrid, Spain), AN(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France;) |
| Journal: | Geophysical Research Letters, Volume 53, Issue 8, id.e2025GL117975, 13 pp. |
| Publication Date: | Apr 2026 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, turbulence, winds, near-surface |
| Abstract Copyright: | © 2026 The Author(s). |
| DOI: | https://doi.org/10.1029/2025GL117975 |
| Bibliographic Code: | 2026GeoRL..5317975S |
| Abstract: | Turbulent winds are a regular occurrence in planetary boundary layers. Turbulence affects mixing, energy fluxes and forcing on the surface environment. Energy injected into an atmosphere generates eddies of many scales down to a size where molecular viscous forces dominate, termed the Kolmogorov length scale. Here, we present an analysis of the turbulent energy cascade at this scale, the transition between the inertial and dissipative regimes, for the first time on Mars. This analysis is based on data from the SuperCam microphone on the Perseverance mission. We find a distribution of power laws in the inertial regime predominantly between −3 and −1 and the distribution of the Kolmogorov length scale from 0.005 to 0.03 m. This yields estimates of the dissipation rate of turbulence between 0.0001 and 1 ${m}^{2}/{s}^{3}$. We compare these values to those calculated using Monin-Obukhov similarity theory, identifying potential shortcomings for its application on Mars without modification. |
| Title: | Atmospheric Dynamics of IR-Active Particles Released From Mars' Surface |
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| Authors: | Richardson, Mark I.; Ansari, Samaneh; Fan, Bowen; Ramirez, Ramses; Mohseni, Hooman; Mischna, Michael A.; Hecht, Michael H.; Steele, Liam J.; Sharipov, Felix; Kite, Edwin S. |
| Affiliation: | AA(Aeolis Research, Chandler, AZ, USA), AB(Northwestern University, Evanston, IL, USA), AC(University of Chicago, Chicago, IL, USA; Now at Yale University, New Haven, CT, USA;), AD(University of Central Florida, Orlando, FL, USA;), AE(Northwestern University, Evanston, IL, USA;), AF(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA;), AG(MIT Haystack Observatory, Westford, MA, USA;), AH(University of Chicago, Chicago, IL, USA; Now at European Center for Medium‐Range Weather Forecasts, Reading, UK), AI(Universidade Federal do Paraná, Curitiba, Brazil), AJ(University of Chicago, Chicago, IL, USA;) |
| Journal: | Geophysical Research Letters, Volume 53, Issue 6, id.e2025GL121051, 11 pp. |
| Publication Date: | Mar 2026 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Earth and Planetary Astrophysics, Geophysics |
| Abstract Copyright: | © 2026. The Author(s). |
| DOI: | https://doi.org/10.1029/2025GL121051 |
| Bibliographic Code: | 2026GeoRL..5321051R |
| Abstract: | Surface release of radiatively active particles, with high infrared- (IR-)to-visible extinction ratios, has been proposed as a method of warming Mars. However, to warm Mars using aerosols, particles released locally must disperse globally. Here we provide an initial reference study in a plume tracking, dry Martian atmospheric model to address this question. The winds that transport aerosols respond to the aerosol's IR forcing, implying strong radiative-dynamical feedbacks (RDF). We investigate RDF from surface release of two particle compositions: carbon (graphene) and metal (Al). Self-lofting helps particles rise and spread locally and regionally, and the Hadley cell strengthens under warming, aiding latitudinal mixing. Within our model, Mars RDF enable engineered-aerosol warming. Warming is slightly greater for three-dimensional vs. 1D-models and also depends on spectral resolution of radiative transfer. We assess implications for Mars warming. Many open atmospheric science questions remain, including the role of agglomeration, dry-deposition rate uncertainty, and modeling water cycle feedbacks. |
| Title: | Reconciling Jupiter's vertical motions with the observed cloud structure in the upper troposphere |
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| Authors: | Mendonça, João M.; Schneider, Tapio; Liu, Junjun; Lian, Yuan |
| Affiliation: | AA(National Space Institute, Technical University of Denmark, Elektrovej, 2800 Kgs. Lyngby, Denmark;), AB(California Institute of Technology, Pasadena, CA 91125, USA), AC(California Institute of Technology, Pasadena, CA 91125, USA), AD(Aeolis Research, Chandler, AZ, 85224, USA) |
| Journal: | Icarus, Volume 443, id.116766. |
| Publication Date: | Jan 2026 |
| Origin: | Elsevier BV |
| Keywords: | Atmospheres, Dynamics, Jupiter, Atmosphere, Jovian planets, Meteorology, Earth and Planetary Astrophysics |
| Abstract Copyright: | © 2025 The Authors. Published by Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2025.116766 |
| Bibliographic Code: | 2026Icar..44316766M |
| Abstract: | The eddy fluxes of angular momentum in Jupiter's upper troposphere are known to converge in prograde jets and diverge in retrograde jets. Away from the equator, this implies convergence of the Eulerian mean meridional flow in zones (anticyclonic shear) and divergence in belts (cyclonic shear). It indicates lower-tropospheric downwelling in zones and upwelling in belts because the mean meridional circulation almost certainly closes at depth. Yet the observed banded structure of Jupiter's clouds and hazes suggests that there is upwelling in the brighter zones and downwelling in the darker belts. Here, we show that this apparent contradiction can be resolved by considering not the Eulerian but the transformed Eulerian mean circulation, which includes a Stokes drift owing to eddies and is a better approximation of the Lagrangian mean transport of tracers such as ammonia. The potential vorticity structure inferred from observations paired with mixing length arguments suggests that there is transformed Eulerian mean upwelling in zones and downwelling in belts. Simulations with a global circulation model of Jupiter's upper atmosphere demonstrate the plausibility of these inferences and allow us to speculate on the band structure at deeper levels. |
| Title: | Equatorial Waves Associated with Dust Storms as Simulated in a Mars General Circulation Model |
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| Authors: | Wang, Huiqun; Richardson, Mark I.; Toigo, Anthony D. |
| Affiliation: | AA(Smithsonian Astrophysical Observatory, Center for Astrophysics Harvard-Smithsonian, Cambridge, MA, USA), AB(Aeolis Research, Chandler, AZ, USA), AC(John Hopkins University Applied Physics Laboratory, Laurel, MD, USA) |
| Journal: | The Planetary Science Journal, Volume 7, Issue 1, id.1, 23 pp. |
| Publication Date: | Jan 2026 |
| Origin: | American Astronomical Society |
| Keywords: | Solar system terrestrial planets, Mars, Atmospheric dynamics, Atmospheric circulation, 797, 1007, 2300, 112 |
| Abstract Copyright: | © 2026. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/ae28d2 |
| Bibliographic Code: | 2026PSJ.....7....1W |
| Abstract: | Equatorial atmospheric waves provide a mechanism for variability on a wide range of timescales and for disturbances in one part of the tropics to influence other tropical locations around the globe. A Mars general circulation model is used to investigate how equatorial waves behave under different atmospheric dust loading scenarios and when perturbed by dust storms. Such waves may be important for understanding triggering of distant dust storms or additional dust lifting centers within large storms. Equatorial waves appear to change when dust storm sequences cross the equator or when background dust amounts significantly vary, with eastward- and westward-propagating waves within a wide spectral interval being amplified in general. Specifically, many low-frequency, long-wavelength equatorial waves become prominent during prescribed dust storm episodes. Their horizontal wave structures seen in the 100 Pa geopotential field show a resemblance to equatorial Rossby, Kelvin, and mixed Rossby─gravity waves. Waves with different wave periods and zonal wavenumbers evolve with time and interfere with each other, leading to complex time-dependent eddy patterns. This study shows that both dust storms and background dust can significantly influence the spectra and structures of eddies in the tropical Martian atmosphere. |