Effect of width, amplitude, and position of a core mantle boundary hot spot on core convection and dynamo action

Dietrich, Wieland; Wicht, Johannes; Hori, Kumiko

doi:10.1186/s40645-015-0065-2

Progress in Earth and Planetary Science

Table 2 Selected numerical models with fixed Rayleigh Ra=4×10⁷, Ekman E=10⁻⁴, and Prandtl Pr=1 numbers and aspect ratio β=0.35

From: Effect of width, amplitude, and position of a core mantle boundary hot spot on core convection and dynamo action

			Hydrodynamic				Magnetic
q ^∗	Ψ [°]	τ [°]	Re	C _EAA	E _m1	Γ	Rm	C _EAA	E _m1	Γ	Λ	H _sur	ω
0	–	–	154.7	0.066	0.029	0.057	224.3	0.007	0.064	0.010	7.83	0.005	–
1	180	0	223.3	0.603	0.013	0.686	446.7	0.747	0.015	0.778	1.71	0.573	49.42
		22	220.9	0.589	0.019	–^a	433.5	0.738	0.022	–^a	2.50	0.561	46.54
		45	213.3	0.535	0.040	–^a	406.3	0.691	0.037	–^a	3.28	0.431	?
		63	198.7	0.375	0.081	–^a	347.4	0.594	0.071	–^a	7.94	0.220	–
		90	181.0	0.029	0.239	–^a	308.7	0.003	0.257	–^a	2.72	–^a	–
	120	0	208.0	0.427	0.023	0.432	428.0	0.759	0.002	0.684	3.94	0.415	25.58
		22	208.9	0.419	0.031	–^a	412.4	0.729	0.024	–^a	4.12	0.410	22.74
		45	198.1	0.370	0.071	–^a	360.1	0.654	0.046	–^a	7.32	0.226	–
		63	184.9	0.229	0.145	–^a	300.1	0.386	0.097	–^a	8.68	0.136	–
		90	168.8	0.016	0.247	–^a	255.6	0.006	0.257	–^a	7.84	–^a	–
	90	0	192.5	0.291	0.029	0.265	365.3	0.703	0.003	0.501	7.94	0.318	–
		22	191.4	0.293	0.038	–^a	369.3	0.698	0.028	–^a	3.69	0.297	–
		45	184.0	0.243	0.102	–^a	291.9	0.483	0.055	–^a	12.87	0.170	–
		63	177.4	0.149	0.164	–^a	283.9	0.262	0.111	–^a	6.98	0.118	–
		90	163.2	0.013	0.231	–^a	239.7	0.006	0.238	–^a	2.40	–^a	–
	60	0	172.1	0.169	0.032	0.194	271.8	0.224	0.144	0.194	10.19	0.077	–
		22	172.0	0.178	0.357	–^a	263.5	0.258	0.111	–^a	11.8	0.065	–
		45	170.4	0.157	0.093	–^a	249.1	0.205	0.075	–^a	11.97	0.060	–
		63	168.9	0.109	0.151	–^a	249.5	0.109	0.155	–^a	8.66	0.047	–
		90	158.0	0.015	0.175	–^a	230.3	0.006	0.237	–^a	0.99	–^a	–
	30	0	158.5	0.083	0.031	0.065	232.5	0.010	0.047	0.057	7.12	0.007	–
		22	158.7	0.091	0.027	–^a	233.6	0.009	0.031	–^a	6.70	0.007	–
		45	158.1	0.093	0.031	–^a	239.1	0.017	0.130	–^a	6.97	0.012	–
		63	157.5	0.087	0.045	–^a	238.2	0.019	0.167	–^a	7.54	0.011	–
		90	151.9	0.027	0.062	–^a	228.7	0.006	0.199	–^a	8.55	–^a	–
0.75	180	0	208.4	0.473	0.015	0.532	425.0	0.763	0.019	0.767	3.69	0.413	34.91
	120	0	198.1	0.340	0.025	0.377	368.8	0.716	0.022	0.462	7.80	0.327	–
	90	0	184.5	0.250	0.028	0.245	346.5	0.666	0.023	0.401	7.11	0.284	–
	60	0	168.1	0.154	0.030	0.163	255.2	0.136	0.132	0.043	9.45	0.054	–
	30	0	158.0	0.085	0.027	0.065	231.2	0.008	0.053	0.010	7.09	0.005	–
0.5	180	0	193.9	0.351	0.023	0.383	347.3	0.725	0.031	0.555	10.75	0.258	–
	120	0	181.8	0.257	0.028	0.272	307.2	0.609	0.033	0.379	14.44	0.193	–
	90	0	173.7	0.195	0.027	0.187	269.9	0.321	0.071	0.193	12.36	0.110	–
	60	0	163.5	0.128	0.027	0.115	245.9	0.078	0.116	0.052	8.72	0.035	–
	30	0	157.3	0.078	0.027	0.083	227.7	0.009	0.064	0.038	7.81	0.007	–
0.25	180	0	166.0	0.173	0.028	0.206	239.5	0.183	0.086	0.2	13.20	0.060	–
	120	0	163.5	0.147	0.027	0.163	237.8	0.110	0.117	0.111	11.08	0.052	–
	90	0	161.6	0.122	0.028	0.095	237.7	0.074	0.105	0.048	9.32	0.033	–
	60	0	158.2	0.089	0.026	0.070	231.7	0.009	0.092	0.070	7.59	0.015	–
	30	0	155.3	0.067	0.026	0.043	227.7	0.009	0.068	0.024	7.58	0.008	–

The magnetic Prandtl number was kept constant at Pm=2 throughout all magnetic simulations. If the magnetic field reverses, the oscillation frequency is given in multiples of 2πPm/τ _vis. Note that for q ^∗=1, Ψ= 180°, and τ= 45°, the field reverses but with an unclear frequency (?). Non-oscillating dynamos are marked with ’-’
^aThe quantities of entries were not calculated. This applies to both convective Γ and magnetic H _sur hemisphericity

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