Editing Great Red Spot (section)

== Internal depth and structure ==
[[File:Telescopes and Spacecraft Join Forces to Probe Deep into Jupiter's Atmosphere (49892941386).png|thumb|400x400px|Clockwise from top left: [[Hubble Space Telescope|Hubble]] image of [[visible spectrum]]; [[infrared]] from the [[Gemini Observatory]];
multiwavelength composite of Hubble and Gemini data showing visible light in blue and thermal infrared in red; [[ultraviolet]] image from Hubble; visible light detail <ref>{{cite journal |last1=Wong |first1=Michael H. |last2=Simon |first2=Amy A. |last3=Tollefson |first3=Joshua W. |last4=de Pater |first4=Imke |last5=Barnett |first5=Megan N. |last6=Hsu |first6=Andrew I. |last7=Stephens |first7=Andrew W. |last8=Orton |first8=Glenn S. |last9=Fleming |first9=Scott W. |last10=Goullaud |first10=Charles |last11=Januszewski |first11=William |last12=Roman |first12=Anthony |last13=Bjoraker |first13=Gordon L. |last14=Atreya |first14=Sushil K. |last15=Adriani |first15=Alberto |last16=Fletcher |first16=Leigh N. |title=High-resolution UV/Optical/IR Imaging of Jupiter in 2016–2019 |journal=The Astrophysical Journal Supplement Series |date=1 April 2020 |volume=247 |issue=2 |pages=58 |doi=10.3847/1538-4365/ab775f|doi-access=free |bibcode=2020ApJS..247...58W }}</ref>]]
Jupiter's Great Red Spot (GRS) is an elliptical-shaped anticyclone, occurring at 22 degrees below the equator, in Jupiter's southern hemisphere.<ref name="gas-composition">{{Cite journal |last1=Bjoraker |first1=G. L. |last2=Wong |first2=M. H. |last3=Pater |first3=I. de |last4=Hewagama |first4=T. |last5=Ádámkovics |first5=M. |last6=Orton |first6=G. S. |date=2018-08-20 |title=The Gas Composition and Deep Cloud Structure of Jupiter's Great Red Spot |journal=The Astronomical Journal |volume=156 |issue=3 |page=101 |doi=10.3847/1538-3881/aad186 |arxiv=1808.01402 |bibcode=2018AJ....156..101B |s2cid=119365729 |issn=1538-3881 |doi-access=free }}</ref> The largest [[Anticyclone|anticyclonic]] storm ({{nowrap|~16,000 km}}) in the [[Solar System]], little is known about its internal depth and structure.<ref name="depth-grs-juno">{{Cite journal |last1=Parisi |first1=Marzia |last2=Kaspi |first2=Yohai |last3=Galanti |first3=Eli |last4=Durante |first4=Daniele |last5=Bolton |first5=Scott J. |last6=Levin |first6=Steven M. |last7=Buccino |first7=Dustin R. |last8=Fletcher |first8=Leigh N. |last9=Folkner |first9=William M. |last10=Guillot |first10=Tristan |last11=Helled |first11=Ravit |date=2021-11-19 |title=The depth of Jupiter's Great Red Spot constrained by Juno gravity overflights |url=https://www.science.org/doi/10.1126/science.abf1396 |journal=Science |language=en |volume=374 |issue=6570 |pages=964–968 |doi=10.1126/science.abf1396 |pmid=34709940 |bibcode=2021Sci...374..964P |s2cid=240153766 |issn=0036-8075|hdl=11573/1605351 |hdl-access=free }}</ref> Visible imaging and cloud-tracking from [[In situ|in-situ]] observation determined the velocity and vorticity of the GRS, which is located in a thin anticyclonic ring at 70–85% of the radius and is located along Jupiter's fastest westward moving jet stream.<ref name="thermal-structure">{{Cite journal |last1=Fletcher |first1=Leigh N. |last2=Orton |first2=G. S. |last3=Mousis |first3=O. |last4=Yanamandra-Fisher |first4=P. |last5=Parrish |first5=P. D. |last6=Irwin |first6=P. G. J. |last7=Fisher |first7=B. M. |last8=Vanzi |first8=L. |last9=Fujiyoshi |first9=T. |last10=Fuse |first10=T. |last11=Simon-Miller |first11=A. A. |date=2010-07-01 |title=Thermal structure and composition of Jupiter's Great Red Spot from high-resolution thermal imaging |url=https://www.sciencedirect.com/science/article/pii/S0019103510000084 |journal=Icarus |language=en |volume=208 |issue=1 |pages=306–328 |doi=10.1016/j.icarus.2010.01.005 |bibcode=2010Icar..208..306F |issn=0019-1035}}</ref> During NASA's 2016 [[Juno (spacecraft)|''Juno'']] mission, gravity signature and thermal infrared data were obtained that offered insight into the structural dynamics and depth of the GRS.<ref name="velocity-vorticity">{{Cite journal |last1=Choi |first1=David S. |last2=Banfield |first2=Don |last3=Gierasch |first3=Peter |last4=Showman |first4=Adam P. |date=2007-05-01 |title=Velocity and vorticity measurements of Jupiter's Great Red Spot using automated cloud feature tracking |url=https://www.sciencedirect.com/science/article/pii/S0019103506004179 |journal=Icarus |language=en |volume=188 |issue=1 |pages=35–46 |doi=10.1016/j.icarus.2006.10.037 |arxiv=1301.6119 |bibcode=2007Icar..188...35C |s2cid=55114257 |issn=0019-1035}}</ref><ref name="depth-grs-juno"/><ref name="thermal-structure"/> During July 2017, the ''Juno'' spacecraft conducted a second pass of the GRS to collect [[Microwave Radiometer (Juno)|Microwave Radiometer]] (MWR) scans of the GRS to determine how far the GRS extended toward the surface of the condensed {{chem|H|2|O}} layer.<ref name="depth-grs-juno"/> These MWR scans suggested that the GRS vertical depth extended to about {{nowrap|240 km}} below cloud level, with an estimated drop in atmospheric pressure to {{nowrap|100 bar}}.<ref name="depth-grs-juno"/><ref name="thermal-structure"/> Two methods of analysis that constrain the data collected were the [[mascon]] approach, which found a depth of {{nowrap|~290 km}}, and the Slepian approach showing wind extending to {{nowrap|~310 km}}.<ref name="depth-grs-juno"/> These methods, along with gravity signature MWR data, suggest that the GRS zonal winds still increase at a rate of 50% of the velocity of the viable cloud level, before the wind decay starts at lower levels. This rate of wind decay and gravity data suggest the depth of the GRS is between 200 and {{nowrap|500 km}}.<ref name="depth-grs-juno"/>

[[Galileo (spacecraft)|Galileo]] and [[Cassini–Huygens|Cassini's]] thermal infrared imaging and [[spectroscopy]] of the GRS were conducted during 1995–2008, in order to find evidence of thermal inhomogeneities within the internal structure vortex of the GRS.<ref name="thermal-structure"/> Previous thermal infrared temperature maps from the [[Voyager program|Voyager]], Galileo, and Cassini missions suggested the GRS is a structure of an anticyclonic vortex with a cold core within a upwelling warmer annulus; this data shows a gradient in the temperature of the GRS.<ref name="gas-composition"/><ref name="thermal-structure"/> Better understanding of Jupiter's atmospheric temperature, aerosol particle opacity, and ammonia gas composition was provided by thermal-IR imaging: a direct correlation of the visible cloud layers reactions, thermal gradient and compositional mapping to observational data were collected over decades.<ref name="gas-composition"/><ref name="thermal-structure"/> During December 2000, high spatial resolution images from Galileo, of an atmospheric turbulent area to the northwest of the GRS, showed a thermal contrast between the warmest region of the anticyclone and regions to the east and west of the GRS.<ref name="thermal-structure"/><ref>{{Cite journal |last1=Sánchez-Lavega |first1=A. |last2=Hueso |first2=R. |last3=Eichstädt |first3=G. |last4=Orton |first4=G. |last5=Rogers |first5=J. |last6=Hansen |first6=C. J. |last7=Momary |first7=T. |last8=Tabataba-Vakili |first8=F. |last9=Bolton |first9=S. |date=2018-09-18 |title=The Rich Dynamics of Jupiter's Great Red Spot from JunoCam: Juno Images |journal=The Astronomical Journal |volume=156 |issue=4 |page=162 |doi=10.3847/1538-3881/aada81 |bibcode=2018AJ....156..162S |s2cid=125185665 |issn=1538-3881|doi-access=free }}</ref>

[[File:Winds in Jupiter’s Great Red Spot.jpg|left|thumb|400x400px|Winds in the Great Red Spot as analyzed from Hubble's data. In the false-color image at right, red indicates faster wind, blue indicates slower.<ref>{{cite journal |last1=Wong |first1=Michael H. |last2=Marcus |first2=Philip S. |last3=Simon |first3=Amy A. |last4=de Pater |first4=Imke |last5=Tollefson |first5=Joshua W. |last6=Asay-Davis |first6=Xylar |title=Evolution of the Horizontal Winds in Jupiter's Great Red Spot From One Jovian Year of HST/WFC3 Maps |journal=Geophysical Research Letters |date=28 September 2021 |volume=48 |issue=18 |doi=10.1029/2021GL093982|bibcode=2021GeoRL..4893982W }}</ref>]]
The vertical temperature{{clarify|date=March 2025}} of the structure of the GRS is constrained to be between 100 and {{nowrap|600 mbar}}, with the vertical temperature{{clarify|date=March 2025}} of the GRS core at approximately {{nowrap|400 mbar}} of pressure{{clarify|date=May 2023}} being {{nowrap|1.0–1.5 K}}, much warmer than regions of the GRS to the east–west, and {{nowrap|3.0–3.5 K}} warmer than regions to the north–south of the structure's edge.{{clarify|date=March 2025}}{{Fix|text=This seems to imply that the latter are below absolute zero!}}<ref name="thermal-structure"/> This structure is consistent with the data collected by the VISIR (VLT Mid-Infrared Imager Spectrometer on the ESO Very Large Telescope) imaging obtained in 2006; this revealed that the GRS was physically present at a wide range of altitudes that occur within the atmospheric pressure range of {{nowrap|80–600 mbar}}, and confirms the thermal infrared mapping result.<ref name="thermal-structure"/><ref name="velocity-vorticity"/><ref>{{Cite journal |last1=Simon |first1=Amy A. |last2=Tabataba-Vakili |first2=Fachreddin |last3=Cosentino |first3=Richard |last4=Beebe |first4=Reta F. |last5=Wong |first5=Michael H. |last6=Orton |first6=Glenn S. |date=2018-03-13 |title=Historical and Contemporary Trends in the Size, Drift, and Color of Jupiter's Great Red Spot |journal=The Astronomical Journal |volume=155 |issue=4 |page=151 |doi=10.3847/1538-3881/aaae01 |bibcode=2018AJ....155..151S |s2cid=126147959 |issn=1538-3881|doi-access=free }}</ref> To develop a model of the internal structure of the GRS, the Cassini instrument Composite [[Infrared spectroscopy|Infrared Spectrometer]] (CIRS) and ground based spatial imaging mapped the composition of the [[phosphine]] and [[ammonia]] aerosols ({{chem|PH|3}}, {{chem|NH|3}}) and [[para-hydroxybenzoic acid]] within the anticyclonic circulation of the GRS.<ref name="thermal-structure"/><ref>{{Cite journal |last1=Cho |first1=James Y-K. |last2=de la Torre Juárez |first2=Manuel |last3=Ingersoll |first3=Andrew P. |last4=Dritschel |first4=David G. |date=2001-03-25 |title=A high-resolution, three-dimensional model of Jupiter's Great Red Spot |journal=Journal of Geophysical Research: Planets |language=en |volume=106 |issue=E3 |pages=5099–5105 |doi=10.1029/2000JE001287|bibcode=2001JGR...106.5099C |doi-access=free }}</ref> The images that were collected from the CIRS and ground-based imaging trace the vertical motion in the Jovian atmosphere by {{chem|PH|3}} and {{chem|NH|3}} spectra.<ref name="gas-composition"/><ref name="thermal-structure"/>

The highest concentrations of {{chem|PH|3}} and {{chem|NH|3}} were found to the north of the GRS peripheral rotation. They aided in determining the southward jet movement and showed evidence of an increase in altitude of the column of aerosols with pressures ranging from {{nowrap|200–500 mbar}}.<ref name="thermal-structure"/><ref>{{Cite journal |last1=Morales-Juberías |first1=Raúl |last2=Dowling |first2=Timothy E. |date=2013-07-01 |title=Jupiter's Great Red Spot: Fine-scale matches of model vorticity patterns to prevailing cloud patterns |url=https://www.sciencedirect.com/science/article/pii/S0019103513001425 |journal=Icarus |language=en |volume=225 |issue=1 |pages=216–227 |doi=10.1016/j.icarus.2013.03.026 |bibcode=2013Icar..225..216M |issn=0019-1035}}</ref> However, the {{chem|NH|3}} composition data shows that there is a major depletion of {{chem|NH|3}} below the visible cloud layer at the southern peripheral ring of the GRS; this lower opacity is relative to a narrow band of atmospheric subsidence.<ref name="thermal-structure"/> The low mid-IR aerosol opacity, along with the temperature gradients, the altitude difference, and the vertical movement of the zonal winds, are involved with the development and sustainability of the vorticity.<ref name="thermal-structure"/> The stronger atmospheric [[subsidence]] and compositional asymmetries of the GRS suggest that the structure exhibits a degree of tilt from the northern edge to the southern edge of the structure.<ref name="thermal-structure"/><ref>{{Cite journal |last1=Flasar |first1=F. Michael |last2=Conrath |first2=Barney J. |last3=Pirraglia |first3=Joseph A. |last4=Clark |first4=Patrick C. |last5=French |first5=Richard G. |last6=Gierasch |first6=Peter J. |date=1981-09-30 |title=Thermal structure and dynamics of the Jovian atmosphere 1. The great red spot |url=http://doi.wiley.com/10.1029/JA086iA10p08759 |journal=Journal of Geophysical Research: Space Physics |language=en |volume=86 |issue=A10 |pages=8759–8767 |doi=10.1029/JA086iA10p08759|bibcode=1981JGR....86.8759F |hdl=2060/19810016481 |hdl-access=free }}</ref> The GRS depth and internal structure has been constantly changing over decades;<ref name="depth-grs-juno"/> however there is still no logical reason that it is {{nowrap|200–500 km}} in depth, but the jet streams that supply the force that powers the GRS vortex are well below the structure base.<ref name="depth-grs-juno"/><ref name="thermal-structure"/>