Comparison of characteristics of the vertical structure of atmosphere's aerosol component in latitudinal belts of Saturn
|1Ovsak, AS, 2Karimov, AM, 2Lysenko, PG |
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Fesenkov Astrophysical Institute, Almaty, Kazakhstan
|Kinemat. fiz. nebesnyh tel (Online) 2018, 34(2):55-70|
|Start Page: Dynamics and Physics of Solar System Bodies|
With using of spectral values of the reflectivity of latitudinal belts of the Northern hemisphere of Saturn measured in 2015 in the methane absorption bands at 727 and 619 nm, the altitude dependences of the aerosol and gas scattering components of the effective optical depth were calculated. Zonal characteristics of the vertical structure of the cloud cover of Saturn are determined. A presence of an aerosol has been identified in all latitudinal belts. The relative concentration of aerosol particles decreases monotonically into the depth of atmospheric column, without attributes of significant condensation and rarefaction of clouds. The greatest amount of aerosol was determined for the latitude region of 49°N and the smallest quantity for 80°N. An altitude level have been identified at which may alter the size and / or the refractive index of aerosol particles. The atmospheric level with the maximum relative concentration of aerosol particles has not been determined, but the nature of obtained dependences indicates its probable location in the higher layers of the atmosphere of the giant planet.
|Keywords: atmosphere, cloud cover, latitudinal belts, Saturn|
1.O. I. Bugaenko, L. S. Galkin, and A. V. Morozhenko, “Polarimetric studies of giant planets. I. Polarization distribution over the Jupiter’s disc,” Astron. Zh. 48, 373–379 (1971).
2.O. I. Bugaenko, Z. M. Dlugach, A. V. Morozhenko, and E. G. Yanovitskii, “On optical properties of the cloud layer of Saturn in the visible region of the spectrum,” Astron. Vestn. 9 (1), 13–21 (1975).
3.A. P. Vid’machenko, “Seasons on Saturn. I. Changes in reflecting characteristics of the atmosphere at 1964–2012,” Vestn. Astron. Shk. 11 (1), 1–14 (2015).
4.A. M. Karimov, P. G. Lysenko, V. G. Tejfel, and G. A. Kharitonova, “Northern hemisphere of Saturn — The methane and ammonia absorption in 2015,” Izv. Akad. Nauk Resp. Kaz., Ser. Fiz.-Mat., No. 5, 97–104 (2016).
5.A. V. Morozhenko, “Jovian cloud stratification,” Sov. Astron. Lett. 10, 323–325 (1984).
6.A. S. Ovsak, “On Determining the Vertical Structure of the Aerosol Component in the Atmosphere of Saturn,” Kinematics Phys. Celestial Bodies 34 (1), 37–51 (2018).
7.J. J. Blalock, R. L. Draham, J. A. Holmes, and K. M. Sayanagi, “Zonal wind speeds, vortex characteristics, and wave dynamics in Saturn’s northern hemisphere,” Bull. Am. Astron. Soc. 45, 312.10 (2013).
8.O. I. Bugaenko and A. V. Morozhenko, “Physical characteristics of the upper layers of Saturn’s atmosphere,” Adv. Space Res. 1 (8), 183–186 (1981).
9.R. W. Carlson, K. H. Baines, M. S. Anderson, G. Filacchione, and A. A. Simon, “Chromophores from photolyzed ammonia reacting with acetylene: Application to Jupiter’s Great Red Spot,” Icarus 274, 106–115 (2016).
10.J. W. Chamberlain, “The atmosphere of Venus near cloud top,” Astrophys. J. 141, 1184–1205 (1965).
11.N. J. Chanover, G. L. Bjoraker, D. A. Glenar, T. Hewagama, and K. H. Baines, “Latitudinal variations of Saturn’s near-infrared spectrum,” in Proc. American Geophysical Union 2005 Fall Meeting, San Francisco, CA, Dec. 5–9, 2005 (AGU, Washington, DC, 2005), abstract no. P11C-0135.
12.J. E. P. Connerney, “Magnetic connection for Saturn’s rings and atmosphere,” Geophys. Res. Lett. 13, 773–776 (1986).
13.R. Courtin, D. Gautier, A. Marten, B. Bezard, and R. Hanel, “The composition of Saturn’s atmosphere at Northern temperate latitudes from Voyager IRIS spectra: NH3, PH3, C2H2, C2H6, CH3D, CH4, and the Saturnian D/H ratio,” Astrophys. J. 287, 899–916 (1984).
14.Z. M. Dlugach, A. V. Morozhenko, A. P. Vid’machenko, and E. G. Yanovitskij, “Investigations of the optical properties of Saturn’s atmosphere carried out at the main astronomical observatory of the Ukrainian Academy of Sciences,” Icarus 54, 319–336 (1983).
15.L. N. Fletcher, K. H. Baines, T. W. Momary, A. P. Showman, P. G. J. Irwin, G. S. Orton, M. Roos-Serote, and C. Merlet, “Saturn’s tropospheric composition and clouds from Cassini/VIMS 4.6–5.1 µm nightside spectroscopy,” Icarus 214, 510–533 (2011).
16.J. S. Hall, L. A. Rilley, “A photometric study of Saturn and its rings,” Icarus 23, 144–156 (1974).
17.M. A. Janssen, A. Ingersoll, M. D. Allison, S. Gulkis, A. Laraia, K. Baines, S. Edgington, Y. Anderson, and K. Kelleher, “Saturn’s thermal emission at 2.2-cm wavelength as imaged by the Cassini RADAR radiometer,” Icarus 226, 522–535 (2013).
18.E. Karkoschka, “Spectrophotometry of the Jovian planets and Titan at 300-to 1000-nm wavelength: The methane spectrum,” Icarus 111, 174–192 (1994).
19.J. S. Lewis, “The clouds of Jupiter and the NH3–H2O and NH3–H2S systems,” Icarus 10, 365–378 (1969).
20.M. Mischenko, “The program for computing far-field light scattering by polydisperse homogeneous spherical particles using the Lorenz–Mie theory”. https://www.giss.nasa.gov/~crmim/publications/index.html.
21.A. V. Morozhenko, “New determination of monochromatic methane absorption coefficients with regard to the thermal conditions in the atmospheres of giant planets. IV. Jupiter and Saturn,” Kinematics Phys. Celestial Bodies 23, 245–257 (2007).
22.A. V. Morozhenko and A. S. Ovsak, “Dependence of the aerosol component of optical thickness and the relative concentration of methane on depth in atmospheres of giant planets,” Kinematics Phys. Celestial Bodies 25, 173–181 (2009).
23.A. V. Morozhenko and A. S. Ovsak, “On the possibility of separation of aerosol and methane absorption in the long-wavelength spectral range for giant planets,” Kinematics Phys. Celestial Bodies 31, 225–231 (2015).
24.A. S. Ovsak, “Calculation of effective optical depth of absorption line formation in homogeneous semi-infinite planetary atmosphere during anisotropic scattering,” Kinematics Phys. Celestial Bodies 26, 86–88 (2010).
25.A. S. Ovsak, “Upgraded technique to analyze the vertical structure of the aerosol component of the atmospheres of giant planets,” Kinematics Phys. Celestial Bodies 29, 291–300 (2013).
26.A. S. Ovsak, “Changes in the characteristics of the upper layers of the Jovian atmosphere from the data on the integral observations of the planetary disk,” Kinematics Phys. Celestial Bodies 31, 25–33 (2015).
27.A. S. Ovsak, “Variations of the volume scattering coefficient of aerosol in the Jovian atmosphere from observations of the planetary disk,” Kinematics Phys. Celestial Bodies 31, 197–204 (2015).
28.A. S. Ovsak, “Vertical structure of cloud layers in the atmospheres of giant planets. I. On the influence of variations of some atmospheric parameters on the vertical structure characteristics,” Sol. Syst. Res. 49, 43–50 (2015).
29.A. S. Ovsak, V. G. Tejfel, A. P. Vid’machenko, P. G. Lysenko, “Zonal differences in the vertical structure of the cloud cover of Jupiter from the measurements of the methane absorption bands at 727 and 619 nm,” Kinematics Phys. Celestial Bodies 31, 119–130 (2015).
30.O. Ovsak and N. Kostogryz, “The method of computer analysis a vertical structure of aerosol component in the atmospheres of the giant planets,” in Proc. AGU Chapman Conf. on Crossing Boundaries in Planetary Atmospheres: From Earth to Exoplanets, Annapolis, MD, June 24–28, 2013 (American Geophysical Union, Washington, DC, 2013), abstract W3.
31.S. Pérez-Hoyos, A. Sánchez-Lavega, and R. G. French, “Short-term changes in the belt/zone structure of Saturn’s southern hemisphere (1996–2004),” Astron. Astrophys. 460, 641–645 (2006).
32.S. Pérez-Hoyos and A. Sánchez-Lavega, “On the vertical wind shear of Saturn’s Equatorial Jet at cloud level,” Icarus 180, 161–175 (2006).
33.A. Sánchez-Lavega, G. Fischer, L. N. Fletcher, E. García-Melendo, B. Hesman, S. Pérez-Hoyos, K. M. Sayanagi, and L. A. Sromovsky, “The great Saturn storm of 2010–2011,” in Saturn in the 21st Century (Cambridge Univ. Press, Cambridge, 2016), Ch. 13. arXiv 1611.07669
34.R. Santer and A. Dollfus, “Optical reflectance polarimetry of Saturn’s globe and rings: IV. Aerosols in the upper atmosphere of Saturn,” Icarus 48, 496–518 (1981).
35.L. A. Sromovsky, K. H. Baines, P. M. Fry, “Evidence for Ammonia and water ices as the primary components of cloud particles in Saturn’s Great Storm of 2010–2011,” in Proc. American Astronomical Society, 45th DPS Meeting, 2013, paper id. 509.08.
36.L. A. Sromovsky, K. H. Baines and P. M. Fry, “Saturn’s Great Storm of 2010–2011: Evidence for ammonia and water ices from analysis of VIMS spectra,” Icarus 226, 402–418 (2013).
37.D. Stam, D. Banfield, P. J. Gierasch, and P. D. Nicholson, “Near-IR spectrophotometry of Saturnian aerosols — Meridional and vertical distribution,” Icarus 152, 407–422 (2001).
38.V. G. Tejfel, A. M. Karimov, G. A. Kharitonova, and G. A. Kirienko, “Spectrophotometric study of Saturn’s atmosphere during a 16-year period (1995–2010), ” Astron. Astrophys. Trans. 28 (2), 121–134 (2013).
39.T. Temma, N. J. Chanover, A. A. Simon-Miller, D. A. Glenar, J. J. Hillman, and D. M. Kuehn, “Vertical structure modeling of Saturn’s equatorial region using high spectral resolution imaging,” Icarus 175, 464–489 (2005).
40.A. P. Vidmachenko, Zh. M. Dlugach, and A. V. Morozhenko, “Nature of the optical nonuniformity in Saturn’s disk,” Sol. Syst. Res. 17, 164–171 (1984).
41.M. B. Vincent, J. T. Clarke, and J. T. Trauger, “The correlation of zonal bands and zonal winds in HST/STIS images of Jupiter and Saturn,” in Proc. American Astronomical Society, 32th DPS Meeting, Pasadena, CA, Oct. 23–27, 2000, paper id. 10.11; Bull. Am. Astron. Soc. 32, 1008 (2000).
42.S. J. Weidenschilling, and L. S. Lewis, “Atmospheric and cloud structures of the Jovian planets,” Icarus 20, 465–476 (1973).
43.R. West, “Clouds and aerosols in Saturn’s atmosphere,” Presented at Saturn Science Conf.: Saturn in the 21st Century, Madison, WI, Aug. 4–7, 2014. http://www.ssec.wisc.edu/meetings/21st_saturn/program/Oral_Presentations....
44.R. A. West and L. Li, “A ring-'rain' influence for Saturn’s cloud albedo and temperatures? Evidence pro or con from Voyager, HST, and Cassini,” in Proc. American Astronomical Society, 47th DPS Meeting, National Harbor, MD, Nov. 8–13, 2015, abstract id. 502.08.