Spectral and emissivity analysis of the raised ramparts around Titan's northern lakes
Anezina Solomonidou
(1, 2, 3)
,
Alice Le Gall
(4)
,
M. J. Malaska
(5)
,
S. P. D. Birch
(6)
,
R. M. C. Lopes
(5)
,
A. Coustenis
(3)
,
S. Rodriguez
(7)
,
S. D. Wall
(5)
,
R. J. Michaelides
(8)
,
M. R. Nasr
(9)
,
C. Elachi
(2)
,
A. G. Hayes
(6)
,
J. M. Soderblom
(9)
,
A. M. Schoenfeld
(10)
,
C. Matsoukas
(11)
,
Pierre Drossart
(3)
,
M. A. Janssen
(5)
,
K. J. Lawrence
(5)
,
Olivier Witasse
(12)
,
J. Yates
(1, 3, 13)
,
J. Radebaugh
(14)
1
ESAC -
European Space Astronomy Centre
2 CALTECH - California Institute of Technology
3 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
4 PLANETO - LATMOS
5 JPL - Jet Propulsion Laboratory
6 Cornell University [New York]
7 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
8 Physics Department [Stanford]
9 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
10 EPSS - Department of Earth, Planetary and Space Sciences [Los Angeles]
11 KTH - KTH Royal Institute of Technology [Stockholm]
12 ESTEC - European Space Research and Technology Centre
13 CZU - Czech University of Life Sciences Prague
14 Department of Geological Sciences [BYU]
2 CALTECH - California Institute of Technology
3 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
4 PLANETO - LATMOS
5 JPL - Jet Propulsion Laboratory
6 Cornell University [New York]
7 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
8 Physics Department [Stanford]
9 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
10 EPSS - Department of Earth, Planetary and Space Sciences [Los Angeles]
11 KTH - KTH Royal Institute of Technology [Stockholm]
12 ESTEC - European Space Research and Technology Centre
13 CZU - Czech University of Life Sciences Prague
14 Department of Geological Sciences [BYU]
Alice Le Gall
- Fonction : Auteur
- PersonId : 175953
- IdHAL : alicelegall
- ORCID : 0000-0002-9023-4868
- IdRef : 128949678
A. Coustenis
- Fonction : Auteur
- PersonId : 738775
- IdHAL : athena-coustenis
- ORCID : 0000-0003-3414-3491
- IdRef : 095079815
S. Rodriguez
- Fonction : Auteur
- PersonId : 1120973
- IdHAL : sebastien-rodriguez
- ORCID : 0000-0003-1219-0641
- IdRef : 089333438
Pierre Drossart
- Fonction : Auteur
- PersonId : 738570
- IdHAL : pierre-drossart
- ORCID : 0000-0001-7261-0228
- IdRef : 089042514
Olivier Witasse
- Fonction : Auteur
- PersonId : 755960
- ORCID : 0000-0003-3461-5604
Résumé
Some of Titan's small northern hemisphere lakes show raised rampart features (which are distinct from raised rims), and appear as SAR-bright mound-like annuli extending away from the lake for up to tens of kilometers from the shoreline. We investigate the infrared and microwave characteristics of these features using Cassini Visual and Infrared Mapping Spectrometer (VIMS) and RADAR data. A spectral comparative analysis is performed among the lakes, their ramparts, and the surrounding regions. We overcome the profound difference in spatial resolution between VIMS and SAR data by using a method that provides overlays between the spectral images and SAR, thus enabling the correct selection of VIMS pixels. The surface properties of the selected areas are obtained using a radiative transfer analysis on the selected VIMS pixels, in addition to emissivity obtained from the RADAR in radiometry mode. Analysis of these combined and co-registered data provides constraints for the formation mechanism(s) of raised ramparts. The results show that the emissivity of the raised ramparts is close to that of Titan's labyrinthic terrains and to that of empty lake floors in the northern polar regions. This is confirmed by the VIMS analysis that also shows that the infrared spectral response of the raised ramparts is very similar to that of some empty lake floors. This suggests that both areas are made from or are covered by a similar material. In addition, two out of the eight lakes with raised ramparts show spectral differences at three specific wavelengths, 1.6, 2.0, and 5.0 μm, between the ramparts and the surrounding terrain. We hypothesize that this could be due to some component, or mixture of components in the ramparts that is less absorbent at these specific wavelengths, or it could be an effect of different grain sizes. These observations provide first insights into the possible mechanisms leading to the formation of the raised ramparts that are discussed here.
Domaines
Astrophysique [astro-ph] Astrophysique [astro-ph] Planétologie et astrophysique de la terre [astro-ph.EP] Planétologie et astrophysique de la terre [astro-ph.EP]Format du dépôt | Fichier |
---|---|
Type de dépôt | Article dans une revue |
Titre |
en
Spectral and emissivity analysis of the raised ramparts around Titan's northern lakes
|
Résumé |
en
Some of Titan's small northern hemisphere lakes show raised rampart features (which are distinct from raised rims), and appear as SAR-bright mound-like annuli extending away from the lake for up to tens of kilometers from the shoreline. We investigate the infrared and microwave characteristics of these features using Cassini Visual and Infrared Mapping Spectrometer (VIMS) and RADAR data. A spectral comparative analysis is performed among the lakes, their ramparts, and the surrounding regions. We overcome the profound difference in spatial resolution between VIMS and SAR data by using a method that provides overlays between the spectral images and SAR, thus enabling the correct selection of VIMS pixels. The surface properties of the selected areas are obtained using a radiative transfer analysis on the selected VIMS pixels, in addition to emissivity obtained from the RADAR in radiometry mode. Analysis of these combined and co-registered data provides constraints for the formation mechanism(s) of raised ramparts. The results show that the emissivity of the raised ramparts is close to that of Titan's labyrinthic terrains and to that of empty lake floors in the northern polar regions. This is confirmed by the VIMS analysis that also shows that the infrared spectral response of the raised ramparts is very similar to that of some empty lake floors. This suggests that both areas are made from or are covered by a similar material. In addition, two out of the eight lakes with raised ramparts show spectral differences at three specific wavelengths, 1.6, 2.0, and 5.0 μm, between the ramparts and the surrounding terrain. We hypothesize that this could be due to some component, or mixture of components in the ramparts that is less absorbent at these specific wavelengths, or it could be an effect of different grain sizes. These observations provide first insights into the possible mechanisms leading to the formation of the raised ramparts that are discussed here.
|
Auteur(s) |
Anezina Solomonidou
1, 2, 3
, Alice Le Gall
4
, M. J. Malaska
5
, S. P. D. Birch
6
, R. M. C. Lopes
5
, A. Coustenis
3
, S. Rodriguez
7
, S. D. Wall
5
, R. J. Michaelides
8
, M. R. Nasr
9
, C. Elachi
2
, A. G. Hayes
6
, J. M. Soderblom
9
, A. M. Schoenfeld
10
, C. Matsoukas
11
, Pierre Drossart
3
, M. A. Janssen
5
, K. J. Lawrence
5
, Olivier Witasse
12
, J. Yates
1, 3, 13
, J. Radebaugh
14
1
ESAC -
European Space Astronomy Centre
( 231736 )
- Camino bajo del Castillo, s/n, Urbanización Villafranca del Castillo,, Villanueva de la Cañada, E-28692 Madrid
- Espagne
2
CALTECH -
California Institute of Technology
( 340667 )
- 1200 East California Blvd, Pasadena, California 91125
- États-Unis
3
LESIA -
Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
( 1005025 )
- 5, place Jules Janssen 92190 MEUDON
- France
4
PLANETO - LATMOS
( 541921 )
- France
5
JPL -
Jet Propulsion Laboratory
( 61129 )
- 4800 Oak Grove Drive, Pasadena, CA 91109-8099, USA
- États-Unis
6
Cornell University [New York]
( 99874 )
- Ithaca, New York 14853
- États-Unis
7
IPGP (UMR_7154) -
Institut de Physique du Globe de Paris
( 1005035 )
- 1 rue Jussieu, 75238 Paris cedex 05 et Bât. Lamarck A case postale 7011, 75205 Paris CEDEX 13
- France
8
Physics Department [Stanford]
( 4867 )
- Stanford University, School of Humanities and Sciences, 382 Via Pueblo, Stanford, CA 94305
- États-Unis
9
EAPS -
Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
( 111351 )
- Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge, MA 02139-4307
- États-Unis
10
EPSS -
Department of Earth, Planetary and Space Sciences [Los Angeles]
( 438365 )
- Los Angeles, CA 90095-1567
- États-Unis
11
KTH -
KTH Royal Institute of Technology [Stockholm]
( 366312 )
- SE-100 44, Stockholm, Sweden
- Suède
12
ESTEC -
European Space Research and Technology Centre
( 152768 )
- Keplerlaan 1, 2201 Noordwijk
- Pays-Bas
13
CZU -
Czech University of Life Sciences Prague
( 1001878 )
- Kamýcká 129 , 165 00 Praha 6 - Suchdol
- Tchéquie
14
Department of Geological Sciences [BYU]
( 178051 )
- Provo, Utah 84602
- États-Unis
|
Langue du document |
Anglais
|
Date de production/écriture |
2019
|
Nom de la revue |
|
Vulgarisation |
Non
|
Comité de lecture |
Oui
|
Audience |
Internationale
|
Date de publication |
2020
|
Volume |
344
|
Numéro |
July
|
Page/Identifiant |
113338
|
Domaine(s) |
|
Mots-clés |
en
Radiative transfer, Titan surface, Titan hydrology, Radar observations, Spectroscopy
|
ADS Id | 2020Icar..34413338S |
DOI | 10.1016/j.icarus.2019.05.040 |
Origine :
Fichiers éditeurs autorisés sur une archive ouverte
Loading...