Dynamic Europa ocean shows transient Taylor columns and convection driven by ice melting and salinity

被引:32
作者
Ashkenazy, Yosef [1 ]
Tziperman, Eli [2 ,3 ]
机构
[1] Ben Gurion Univ Negev, Blaustein Inst Desert Res, Dept Solar Energy & Environm Phys, IL-84990 Midreshet Ben Gurion, Negev, Israel
[2] Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA
[3] Harvard Univ, Sch Engn & Appl Sci, 20 Oxford St, Cambridge, MA 02138 USA
基金
美国国家航空航天局; 美国国家科学基金会;
关键词
GENERAL-CIRCULATION MODEL; SUBSURFACE OCEAN; WATER; SHELL; HEAT; SIMULATIONS; THICKNESS; STATE; FLOW;
D O I
10.1038/s41467-021-26710-0
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The deep (similar to 100 km) ocean of Europa, Jupiter's moon, covered by a thick icy shell, is one of the most probable places in the solar system to find extraterrestrial life. Yet, its ocean dynamics and its interaction with the ice cover have received little attention. Previous studies suggested that Europa's ocean is turbulent using a global model and taking into account non-hydrostatic effects and the full Coriolis force. Here we add critical elements, including consistent top and bottom heating boundary conditions and the effects of icy shell melting and freezing on ocean salinity. We find weak stratification that is dominated by salinity variations. The ocean exhibits strong transient convection, eddies, and zonal jets. Transient motions organize in Taylor columns parallel to Europa's axis of rotation, are static inside of the tangent cylinder and propagate equatorward outside the cylinder. The meridional oceanic heat transport is intense enough to result in a nearly uniform ice thickness, that is expected to be observable in future missions.
引用
收藏
页数:12
相关论文
共 71 条
[1]   Global surface eddy diffusivities derived from satellite altimetry [J].
Abernathey, R. P. ;
Marshall, J. .
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 2013, 118 (02) :901-916
[2]   The surface temperature of Europa [J].
Ashkenazy, Yosef .
HELIYON, 2019, 5 (06)
[3]   Dynamics of the global meridional ice flow of Europa's icy shell [J].
Ashkenazy, Yosef ;
Sayag, Roiy ;
Tziperman, Eli .
NATURE ASTRONOMY, 2018, 2 (01) :43-49
[4]   Variability, Instabilities, and Eddies in a Snowball Ocean [J].
Ashkenazy, Yosef ;
Tziperman, Eli .
JOURNAL OF CLIMATE, 2016, 29 (02) :869-888
[5]   Ocean Circulation under Globally Glaciated Snowball Earth Conditions: Steady-State Solutions [J].
Ashkenazy, Yosef ;
Gildor, Hezi ;
Losch, Martin ;
Tziperman, Eli .
JOURNAL OF PHYSICAL OCEANOGRAPHY, 2014, 44 (01) :24-43
[6]   Dynamics of a Snowball Earth ocean [J].
Ashkenazy, Yosef ;
Gildor, Hezi ;
Losch, Martin ;
Macdonald, Francis A. ;
Schrag, Daniel P. ;
Tziperman, Eli .
NATURE, 2013, 495 (7439) :90-93
[7]  
Barr AC., 2009, EUROPA, P405
[8]  
Bierhaus E.B., 2009, EUROPA, P161, DOI DOI 10.2307/J.CTT1XP3WDW.13
[9]   The great thickness debate: Ice shell thickness models for Europa and comparisons with estimates based on flexure at ridges [J].
Billings, SE ;
Kattenhorn, SA .
ICARUS, 2005, 177 (02) :397-412
[10]   Evidence for a subsurface ocean on Europa [J].
Carr, MH ;
Belton, MJS ;
Chapman, CR ;
Davies, AS ;
Geissler, P ;
Greenberg, R ;
McEwen, AS ;
Tufts, BR ;
Greeley, R ;
Sullivan, R ;
Head, JW ;
Pappalardo, RT ;
Klaasen, KP ;
Johnson, TV ;
Kaufman, J ;
Senske, D ;
Moore, J ;
Neukum, G ;
Schubert, G ;
Burns, JA ;
Thomas, P ;
Veverka, J .
NATURE, 1998, 391 (6665) :363-365