Table 2 Mars thermophysical properties relevant for dynamo activity

Ω

Rotational frequency

1.28126

×10⁻⁵ s ⁻¹

(Turcotte and Schubert 2002)

R _i

Inner core radius

100

km

R _o

Outer radius of convective region

1100

km

D

Convective region thickness

=R _i −R _o

g ₀

Gravitational acceleration at top of convective region

1.99

m s ⁻²

α

Thermal expansivity

4.7

×10⁻⁵ K ⁻¹

(Helffrich and Kaneshima 2004) for Fe-11wt%S

T _o

Temperature at top of convective region

1850

K

Rivoldini et al. (2011) adiabat

T _{C M B}

CMB temperature

1700

K

(Rivoldini et al. 2011)

C _P

Heat capacity

600

J kg ⁻¹ K ⁻¹

(Helffrich and Kaneshima 2004) for Fe-11wt%S

ρ

Density

6390

kg m ⁻³

(Rivoldini et al. 2011)

ν

Viscosity

1

×10⁻⁶ m ² s ⁻¹

(Christensen and Aubert 2006)

κ

Thermal diffusivity

2

×10⁻⁵ m ² s ⁻¹

(Christensen and Aubert 2006)

k

thermal conductivity in convective region

30

W m ⁻¹ K ⁻¹

(Stacey 1992)

E

Ekman number

8.05

×10⁻¹⁴

=ν(Ω D ²)⁻¹

E _k

Thermal Ekman number

1.61

×10⁻¹²

=κ(Ω D ²)⁻¹

\({Ra}_{Q,c}^{*}\)

Modified critical Rayleigh number

9.19

×10⁻⁹

=R a _c E E _k (Christensen and Aubert 2006);

R a _c from Al-Shamali et al. (2004)