000005572 001__ 5572
000005572 005__ 20220120141343.0
000005572 037__ $$aCTALK-2022-0017
000005572 100__ $$aYan, Chi
000005572 245__ $$aFull sphere dynamo models for Mars' ancient magnetic field
000005572 260__ $$c2021
000005572 269__ $$c2021-12-16
000005572 520__ $$aThe ancient martian dynamo is mysterious in both spatial and temporal features. First, strong crustal magnetic fields are concentrated in the southern hemisphere, whereas the crustal magnetic fields in the northern hemisphere are mostly weak. Second, the ancient martian dynamo appears to have been active both before and after the Late Heavy Bombardment, with a shut down in between. These suggest that Mars’ ancient dynamo might be quite different from the conventional geodynamo. Recent seismic measurements from the NASA Mars InSight mission revealed that Mars’ core has a relatively low density, implying that it contains a larger fraction of lighter elements than previously thought. This could possibly prevent Mars from forming a solid inner core during Mars’ early history when the dynamo was active. Here we perform full sphere dynamo simulations to eliminate the influence of an inner core on dynamo behaviors. Furthermore, we investigate the effects of various heat flux perturbations at the core mantle boundary on the morphology of the resulting field and compare to models with small inner cores. These studies provide insight into Mars’ interior, thermal history and core evolution.
000005572 594__ $$aNO
000005572 6531_ $$aMars, core, dynamo
000005572 700__ $$aBarik, Ankit
000005572 700__ $$aStanley, Sabine
000005572 700__ $$aPlesa, Ana-Catalina
000005572 700__ $$aRivoldini, Attilio
000005572 700__ $$aMittelholz, Anna
000005572 700__ $$aJohnson, Catherine
000005572 773__ $$tAGU Fall Meeting 2021, New Orleans, online
000005572 8560_ $$fattilio.rivoldini@observatoire.be
000005572 906__ $$aContributed
000005572 980__ $$aCTALKCONT