Enceladus parameters
|
a
|
Radius |
252 km |
δ |
Obliquity |
27° |
H
|
Global mean ice thickness |
20.8 km: (18) |
D
|
Global mean ocean depth |
39.2 km: (18) |
Ω |
Rotation rate |
5.307 × 10−5 s−1
|
g
0
|
Surface gravity |
0.113 m/s2
|
|
Mean surface temperature |
59 K |
Europa parameters
|
a
|
Radius |
1561 km |
δ |
Obliquity |
3.1° |
H
|
Global mean ice thickness |
15 km: (53) |
D
|
Global mean ocean depth |
85 km: (53) |
Ω |
Rotation rate |
2.05 × 10−5 s−1
|
g
0
|
Surface gravity |
1.315 m/s2
|
|
Mean surface temperature |
110 K |
Physical constants
|
L
f
|
Fusion energy of ice |
334,000 J/kg |
Cp
|
Heat capacity of water |
4000 J/kg per Kelvin |
Tf(S, P) |
Freezing point |
Eq. 14
|
ρi
|
Density of ice |
917 kg/m3
|
ρw
|
Density of the ocean |
Eq. 12
|
α, β |
Thermal expansion and saline contraction coeff. |
Using Gibbs Seawater Toolbox: (23) |
κ0
|
Conductivity coeff. of ice |
651 W/m: (74) |
p
α
|
Ice dissipation amplification factor |
−2 to −1 |
ηm
|
Ice viscosity at freezing point |
1014 Ps·s |
Default parameters in the ocean model
|
νh, νv
|
Horizontal/vertical viscosity |
10 m2/s |
|
Biharmonic hyperviscosity |
109 m4/s |
κh, κv
|
Horizontal/vertical diffusivity |
0.005 m2/s |
(γT, γS, γM) |
Water-ice exchange coeff. for T, S, and momentum |
(10−5, 10−5, 10−3) m/s |
g
|
Gravity in the ocean |
Eq. 8
|
P
0
|
Reference pressure |
ρig0H = 2.16 × 106 Pa |
θ0
|
Reference potential temperature |
Tf(S0, P0) |
ρw0
|
Reference density of ocean |
Eq. 13
|
ℋcond
|
Conductive heat loss through ice |
Eq. 15, Fig. 7
|
ℋice
|
Tidal heating produced in the ice |
Eq. 26, Fig. 7
|
ℋcore
|
Bottom heat flux powered by the core |
Eq. 16, Fig. 7
|
A
|
Surface albedo |
0.81 |
T
s
|
Surface temperature profile |
Fig. 7
|