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Radiative-convective models of the atmospheres of Uranus and Neptune: heating sources and seasonal effects (2403.13399v1)

Published 20 Mar 2024 in astro-ph.EP

Abstract: The observations made during the Voyager 2 flyby have shown that the stratosphere of Uranus and Neptune are warmer than expected by previous models. In addition, no seasonal variability of the thermal structure has been observed on Uranus since Voyager 2 era and significant subseasonal variations have been revealed on Neptune. In this paper, we evaluate different realistic heat sources that can induce sufficient heating to warm the atmosphere of these planets and we estimate the seasonal effects on the thermal structure. The seasonal radiative-convective model developed by the Laboratoire de M\'et\'eorologie Dynamique is used to reproduce the thermal structure of these planets. Three hypotheses for the heating sources are explored separately: aerosol layers, a higher methane mole fraction, and thermospheric conduction. Our modelling indicates that aerosols with plausible scattering properties can produce the requisite heating for Uranus, but not for Neptune. Alternatively, greater stratospheric methane abundances can provide the missing heating on both planets, but the large values needed are inconsistent with current observational constraints. In contrast, adding thermospheric conduction cannot warm alone the stratosphere of both planets. The combination of these heat sources is also investigated. In the upper troposphere of both planets, the meridional thermal structures produced by our model are found inconsistent with those retrieved from Voyager 2/IRIS data. Furthermore, our models predict seasonal variations should exist within the stratospheres of both planets while observations showed that Uranus seems to be invariant to meridional contrasts and only subseasonal temperature trends are visible on Neptune. However, a warm south pole is seen in our simulations of Neptune as observed since 2003.

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References (126)
  1. Appleby, J. F. (1986). Radiative-convective equilibrium models of Uranus and Neptune. Icarus, 65(2-3):383–405.
  2. Appleby, J. F. (1990). CH 44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT nonlocal thermodynamic equilibrium in the atmospheres of the giant planets. Icarus, 85(2):355–379.
  3. Clouds, Hazes, and the Stratospheric Methane Abundance in Neptune. Icarus, 109(1):20–39.
  4. The oblateness of Uranus at the 1-μ𝜇\muitalic_μbar level. Icarus, 78(1):119–130.
  5. Bezard, B. (1990). Seasonal thermal structure of the atmospheres of the giant planets. Advances in Space Research, 10(1):89–98.
  6. Detection of the Methyl Radical on Neptune. Astrophysical Journal, 515(2):868–872.
  7. Voyager 2 ultraviolet spectrometer solar occultations at Neptune: constraints on the abundance of methane in the stratosphere. Journal of Geophysics Research, 97(E7):11681–11694.
  8. Absorption and scattering of light by small particles. Research supported by the University of Arizona and Institute of Occupational and Environmental Health. New York.
  9. Borysow, A. (1991). Modeling of collision-induced infrared absorption spectra of H 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPT-H 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPT pairs in the fundamental band at temperatures from 20 to 300 K. Icarus, 92(2):273–279.
  10. Semi-empirical Model of Collision-Induced Absorption Spectra of H 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPT-H 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPT Complexes in the Second Overtone Band of Hydrogen at Temperatures from 50 to 500 K. Icarus, 145(2):601–608.
  11. Theoretical Collision-induced Rototranslational Absorption Spectra for the Outer Planets: H 2-CH 4 Pairs. Astrophysical Journal, 304:849.
  12. Collision-induced Rototranslational Absorption Spectra of CH 4-CH 4 Pairs at Temperatures from 50 to 300 K. Astrophysical Journal, 318:940.
  13. Collision-induced Infrared Spectra of H 2-He Pairs at Temperatures from 18 to 7000 K. II. Overtone and Hot Bands. Astrophysical Journal, 341:549.
  14. Collision-induced Infrared Spectra of H 2-He Pairs Involving 0 1 Vibrational Transitions and Temperatures from 18 to 7000 K. Astrophysical Journal, 336:495.
  15. Ultraviolet Spectrometer Observations of Neptune and Triton. Science, 246(4936):1459–1466.
  16. Ultraviolet Spectrometer Observations of Uranus. Science, 233(4759):74–79.
  17. A pole-to-pole pressure-temperature map of Saturn’s thermosphere from Cassini Grand Finale data. Nature Astronomy, 4:872–879.
  18. Neptune’s far-infrared spectrum from the ISO long-wavelength and short-wavelength spectrometers. Icarus, 164(1):244–253.
  19. The first submillimeter observation of CO in the stratosphere of Uranus. Astronomy and Astrophysics, 562:A33.
  20. Infrared Observations of the Neptunian System. Science, 246(4936):1454–1459.
  21. The helium abundance of Uranus from Voyager measurements. Journal of Geophysical Research, 92(A13):15003–15010.
  22. The helium abundance of Neptune from Voyager measurements. Journal of Geophysical Research Supplement, 96(S01):18907.
  23. Temperature and circulation in the stratosphere of the outer planets. Icarus, 83(2):255–281.
  24. Thermal Structure and Para Hydrogen Fraction on the Outer Planets from Voyager IRIS Measurements. Icarus, 135(2):501–517.
  25. Neptune’s global circulation deduced from multi-wavelength observations. Icarus, 237:211–238.
  26. 1D photochemical model of the ionosphere and the stratosphere of Neptune. Icarus, 335:113375.
  27. ISO observations of Uranus: The stratospheric distribution of C_2H_2 and the eddy diffusion coefficient. Astronomy and Astrophysics, 333:L43–L46.
  28. Voyager infrared observations of Uranus’ atmosphere: Thermal structure and dynamics. Journal of Geophysical Research, 92(A13):15011–15018.
  29. Seasonal change on Saturn from Cassini/CIRS observations, 2004-2009. Icarus, 208(1):337–352.
  30. Neptune at summer solstice: Zonal mean temperatures from ground-based observations, 2003-2007. Icarus, 231:146–167.
  31. Ice Giant Circulation Patterns: Implications for Atmospheric Probes. Space Science Reviews, 216(2):21.
  32. Neptune’s atmospheric composition from AKARI infrared spectroscopy. Astronomy and Astrophysics, 514:A17.
  33. Hydrogen Dimers in Giant-planet Infrared Spectra. Astrophysical Journals, 235(1):24.
  34. Seasonal meridional energy balance and thermal structure of the atmosphere of Uranus: A radiative-convective-dynamical model. Icarus, 69(1):135–156.
  35. The correlated-k method for radiation calculations in nonhomogeneous atmospheres. Journal of Quantitiative Spectroscopy and Radiative Transfer, 42:539–550.
  36. A spatially resolved high spectral resolution study of Neptune’s stratosphere. Icarus, 214(2):606–621.
  37. Radiative-equilibrium model of Jupiter’s atmosphere and application to estimating stratospheric circulations. Icarus, 351:113935.
  38. Global climate modeling of Saturn’s atmosphere. Part I: Evaluation of the radiative transfer model. Icarus, 238:110–124.
  39. Temperature dependence of the hydrogen-broadening coefficient for theν𝜈\nuitalic_ν99{}_{9}start_FLOATSUBSCRIPT 9 end_FLOATSUBSCRIPT fundamental of ethane. Journal of Quantitative Spectroscopy and Radiative Transfer, 39:429–434.
  40. Mid-Infrared Ethane Emission on Neptune and Uranus. Astrophysical Journal, 644(2):1326–1333.
  41. Light scattering in planetary atmospheres. Space Science Reviews, 16(4):527–610.
  42. The upper atmosphere of Uranus: EUV occultations observed by Voyager 2. Journal of Geophysical Research, 92(A13):15093–15109.
  43. Meteorological Variability and the Annual Surface Pressure Cycle on Mars. Journal of Atmospheric Sciences, 50(21):3625–3640.
  44. 44{}^{4}start_FLOATSUPERSCRIPT 4 end_FLOATSUPERSCRIPTHe thermophysical properties: New ab initio calculations.
  45. The application of new methane line absorption data to Gemini-N/NIFS and KPNO/FTS observations of Uranus’ near-infrared spectrum. Icarus, 220(2):369–382.
  46. Spectral analysis of Uranus’ 2014 bright storm with VLT/SINFONI. Icarus, 264:72–89.
  47. Multispectral imaging observations of Neptune’s cloud structure with Gemini-North. Icarus, 216(1):141–158.
  48. Hazy Blue Worlds: A Holistic Aerosol Model for Uranus and Neptune, Including Dark Spots. Journal of Geophysical Research (Planets), 127(6):e07189.
  49. Reanalysis of Uranus’ cloud scattering properties from IRTF/SpeX observations using a self-consistent scattering cloud retrieval scheme. Icarus, 250:462–476.
  50. Latitudinal variation in the abundance of methane (CH44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT) above the clouds in Neptune’s atmosphere from VLT/MUSE Narrow Field Mode Observations. Icarus, 331:69–82.
  51. HST/WFC3 observations of Uranus’ 2014 storm clouds and comparison with VLT/SINFONI and IRTF/Spex observations. Icarus, 288:99–119.
  52. Optical properties of carbonaceous dust analogues. Astronomy and Astrophysics, 332:291–299.
  53. Karkoschka, E. (1994). Spectrophotometry of the Jovian Planets and Titan at 300- to 1000-nm Wavelength: The Methane Spectrum. Icarus, 111(1):174–192.
  54. Karkoschka, E. (1997). Rings and Satellites of Uranus: Colorful and Not So Dark. Icarus, 125(2):348–363.
  55. The haze and methane distributions on Uranus from HST-STIS spectroscopy. Icarus, 202(1):287–309.
  56. The haze and methane distributions on Neptune from HST-STIS spectroscopy. Icarus, 211(1):780–797.
  57. Optical constants of organic tholins produced in a simulated Titanian atmosphere: From soft x-ray to microwave frequencies. Icarus, 60(1):127–137.
  58. Production and Optical Constants of Ice Tholin from Charged Particle Irradiation of (1:6) C 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPTH 66{}_{6}start_FLOATSUBSCRIPT 6 end_FLOATSUBSCRIPT/H 22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPTO at 77 K. Icarus, 103(2):290–300.
  59. Photometry from Voyager 2: Initial Results from the Uranian Atmosphere, Satellites, and Rings. Science, 233(4759):65–70.
  60. First results of Herschel-PACS observations of Neptune. Astronomy and Astrophysics, 518:L152.
  61. New constraints on the CH44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT vertical profile in Uranus and Neptune from Herschel observations. Astronomy and Astrophysics, 579:A121.
  62. A high-performance atmospheric radiation package: With applications to the radiative energy budgets of giant planets. Journal of Quantitiative Spectroscopy and Radiative Transfer, 217:353–362.
  63. Lindal, G. F. (1992). The Atmosphere of Neptune: an Analysis of Radio Occultation Data Acquired with Voyager 2. The Astronomical Journal, 103:967.
  64. The atmosphere of Uranus: Results of radio occultation measurements with Voyager 2. Journal of Geophysical Research, 92(A13):14987–15001.
  65. Retrieving Neptune’s aerosol properties from Keck OSIRIS observations. I. Dark regions. Icarus, 276:52–87.
  66. Margolis, J. S. (1993). Measurement of hydrogen-broadened methane lines in the ν𝜈\nuitalic_ν44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT band at 296 and 200K. Journal of Quantitative Spectroscopy and Radiative Transfer, 50(4):431–441.
  67. Thermal Structure of Uranus’ Atmosphere. Icarus, 138(2):268–286.
  68. Improved constraints on Neptune’s atmosphere from submillimetre-wavelength observations. Astronomy and Astrophysics, 429:1097–1105.
  69. Optical constants of liquid and solid methane. Ao, 33(36):8306–8317.
  70. Thermal conductivity of multicomponent gas mixtures. ii. The Journal of Chemical Physics, 31(2):511–514.
  71. Conversion of para and ortho hydrogen in the Jovian planets. Icarus, 49(2):213–226.
  72. Ab Initio Transport Coefficients of Gaseous Hydrogen. International Journal of Thermophysics, 31(4-5):740–755.
  73. The H33{}_{3}start_FLOATSUBSCRIPT 3 end_FLOATSUBSCRIPT+{}^{+}start_FLOATSUPERSCRIPT + end_FLOATSUPERSCRIPT ionosphere of Uranus: decades-long cooling and local-time morphology. Philosophical Transactions of the Royal Society of London Series A, 377(2154):20180408.
  74. Atmospheric implications of the lack of H33{}_{3}start_FLOATSUBSCRIPT 3 end_FLOATSUBSCRIPT+{}^{+}start_FLOATSUPERSCRIPT + end_FLOATSUPERSCRIPT detection at Neptune. Philosophical Transactions of the Royal Society of London Series A, 378(2187):20200100.
  75. Atmospheric chemistry on Uranus and Neptune. Philosophical Transactions of the Royal Society of London Series A, 378(2187):20190477.
  76. Seasonal stratospheric photochemistry on Uranus and Neptune. Icarus, 307:124–145.
  77. Photochemistry and diffusion in Jupiter’s stratosphere: Constraints from ISO observations and comparisons with other giant planets. Journal of Geophysical Research (Planets), 110(E8):E08001.
  78. An analysis of Neptune’s stratospheric haze using high-phase-angle voyager images. Icarus, 113(2):232–266.
  79. Solar System Observations with the James Webb Space Telescope. Publications of the ASP, 128(960):025004.
  80. Uranian ring photometry: Results from Voyager 2. Journal of Geophysical Research, 92(A13):14969–14978.
  81. Global upper-atmospheric heating on Jupiter by the polar aurorae. Nature, 596(7870):54–57.
  82. Thermal imaging of Uranus: Upper-tropospheric temperatures one season after Voyager. Icarus, 260:94–102.
  83. Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere. Icarus, 243:494–513.
  84. The albedo, effective temperature, and energy balance of Neptune, as determined from Voyager data. Journal of Geophysical Research, 96:18921–18930.
  85. The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data. Icarus, 84(1):12–28.
  86. Nature of the stratospheric haze on Uranus: Evidence for condensed hydrocarbons. Journal of Geophysical Research, 92(A13):15037–15065.
  87. High-phase-angle observations of Neptune at 2650 and 7500 Å: Haze structure and particle properties. Icarus, 99(2):302–317.
  88. Properties of scatterers in the troposphere and lower stratosphere of Uranus based on Voyager imaging data. Icarus, 89(2):359–376.
  89. New accurate theoretical line lists of 1212{}^{12}start_FLOATSUPERSCRIPT 12 end_FLOATSUPERSCRIPTCH44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT and 1313{}^{13}start_FLOATSUPERSCRIPT 13 end_FLOATSUPERSCRIPTCH44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT in the 0-13400 cm-11{}^{1}start_FLOATSUPERSCRIPT 1 end_FLOATSUPERSCRIPT range: Application to the modeling of methane absorption in Titan’s atmosphere. Icarus, 303:114–130.
  90. Solar heating of the Uranian mesopause by dust of ring origin. Icarus, 88(2):429–447.
  91. Aerosols and methane in the ice giant atmospheres inferred from spatially resolved, near-infrared spectra: I. Uranus, 2001-2007. Icarus, 310:54–76.
  92. Subseasonal Variation in Neptune’s Mid-infrared Emission. The Planetary Science Journal, 3(4):78.
  93. Uranus in Northern Midspring: Persistent Atmospheric Temperatures and Circulations Inferred from Thermal Imaging. Astronomical Journal, 159(2):45.
  94. Neptune’s upper stratosphere, 1983-1990: ground-based stellar occultation observations III. Temperature profiles. Astronomy and Astrophysics, 288:985–1011.
  95. Longitudinal variations in the stratosphere of Uranus from the Spitzer infrared spectrometer. Icarus, 365:114506.
  96. The upper atmosphere of uranus from stellar occultations. i. methods and validation. The Planetary Science Journal, 4(10):199.
  97. Sromovsky, L. A. (2005). Accurate and approximate calculations of Raman scattering in the atmosphere of Neptune. Icarus, 173(1):254–283.
  98. High S/N Keck and Gemini AO imaging of Uranus during 2012-2014: New cloud patterns, increasing activity, and improved wind measurements. Icarus, 258:192–223.
  99. Spatially resolved cloud structure on Uranus: Implications of near-IR adaptive optics imaging. Icarus, 192(2):527–557.
  100. Methane on Uranus: The case for a compact CH 44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT cloud layer at low latitudes and a severe CH 44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT depletion at high-latitudes based on re-analysis of Voyager occultation measurements and STIS spectroscopy. Icarus, 215(1):292–312.
  101. The methane distribution and polar brightening on Uranus based on HST/STIS, Keck/NIRC2, and IRTF/SpeX observations through 2015. Icarus, 317:266–306.
  102. Methane depletion in both polar regions of Uranus inferred from HST/STIS and Keck/NIRC2 observations. Icarus, 238:137–155.
  103. An Analysis of the Voyager 2 Ultraviolet Spectrometer Occultation Data at Uranus: Inferring Heat Sources and Model Atmospheres. Icarus, 101(1):45–63.
  104. Concerning the rototranslational absorption spectra of He-CH44{}_{4}start_FLOATSUBSCRIPT 4 end_FLOATSUBSCRIPT pairs. Journal of Molecular Spectroscopy, 129(1):45–58.
  105. Uranus’ cloud particle properties and latitudinal methane variation from IRTF SpeX observations. Icarus, 223(2):684–698.
  106. Constraints on Neptune’s haze structure and formation from VLT observations in the H-band. Icarus, 350:113808.
  107. Constraints on Uranus’s haze structure, formation and transport. Icarus, 333:1–11.
  108. Rapid calculation of radiative heating rates and photodissociation rates in inhomogeneous multiple scattering atmospheres. Journal of Geophysical Research, 94:16287–16301.
  109. The habitability of Proxima Centauri b. II. Possible climates and observability. Astronomy and Astrophysics, 596:A112.
  110. An investigation of the temperature variations in Neptune’s upper stratosphere including a July 2008 stellar occultation event. Icarus, 232:22–33.
  111. Wallace, L. (1983). The seasonal variation of the thermal structure of the atmosphere of Uranus. Icarus, 54(1):110–132.
  112. Wallace, L. (1984). The seasonal variation of the thermal structure of the atmosphere of Neptune. Icarus, 59(3):367–375.
  113. Wang, Y. (1993). Energy Balance and Solar Heating in Neptune’s Upper Atmosphere. PhD thesis, University of Arizona.
  114. Uranus and Neptune Albedos May Need Revision. In AGU Fall Meeting Abstracts, volume 2022, pages P32E–1865.
  115. Clouds and aerosols in the Uranian atmosphere. In Bergstralh, J. T., Miner, E. D., and Matthews, M. S., editors, Uranus, pages 296–324. University of Arizona.
  116. Temperature and aerosol structure of the nightside Uranian stratosphere from Voyager 2 photopolarimeter stellar occultation measurements. Journal of Geophysical Research, 92(A13):15030–15036.
  117. Fractal Organic Hazes Provided an Ultraviolet Shield for Early Earth. Science, 328(5983):1266.
  118. Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling. Astronomy and Astrophysics, 522:A22.
  119. Analysis of Raman scattered LY-α𝛼\alphaitalic_α emissions from the atmosphere of Uranus. Geophysics Research Letters, 14(5):483–486.
  120. The Distribution Hydrocarbons in Neptune’s Upper Atmosphere. Icarus, 104(1):38–59.
  121. The far ultraviolet reflection spectrum of Uranus: Results from the Voyager encounter. Icarus, 77(2):439–456.
  122. Uranus after Solstice: Results from the 1998 November 6 Occultation. Icarus, 153(2):236–247.
  123. Zhang, X. (2023a). The Inhomogeneity Effect. I. Inhomogeneous Surface and Atmosphere Accelerate Planetary Cooling. The Astrophysical Journal, 957(1):20.
  124. Zhang, X. (2023b). The Inhomogeneity Effect. II. Rotational and Orbital States Impact Planetary Cooling. The Astrophysical Journal, 957(1):21.
  125. Aerosol influence on energy balance of the middle atmosphere of Jupiter. Nature Communications, 6:10231.
  126. Modeling of collision-induced infrared absorption spectra of H22{}_{2}start_FLOATSUBSCRIPT 2 end_FLOATSUBSCRIPT pairs in the first overtone band at temperatures from 20 to 500K. Icarus, 113(1):84–90.

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