000005258 001__ 5258
000005258 005__ 20210201174832.0
000005258 037__ $$aPOSTER-2021-0017
000005258 100__ $$aYan, Chi
000005258 245__ $$aSensitivity of the ancient martian dynamo to hemispheric CMB heat flux patterns
000005258 260__ $$c2020
000005258 269__ $$c2020-12-15
000005258 520__ $$aMagnetic field observations from the Mars Global Surveyor, MAVEN, and InSight missions reveal that a dynamo was active in Mars’ early history. One unique feature of Mars’ crustal field is its hemispheric dichotomy, with the southern hemisphere crustal fields stronger than those in the northern hemisphere. The hemispheric dichotomy has been previously proposed to be due to either crustal reprocessing or a hemispheric dynamo. Here we use numerical dynamo models to investigate the potential hemispheric nature of Mars’ ancient dynamo. Previous studies show that a hemispheric heat flux perturbation at the core-mantle boundary could result in either a stable hemispherical magnetic field or a constantly reversing field, depending on the choices of parameters used in the models. These two scenarios lead to very different implications for the generation of crustal fields. Here we test the dynamo sensitivity to various heat flux perturbations at the core-mantle boundary in a broader parameter regime than previous studies in order to understand whether a hemispheric dynamo is likely for early Mars. We also compare to constraints available on the martian crustal field intensity determined from the InSight mission.
000005258 594__ $$aNO
000005258 700__ $$aBarik, Ankit
000005258 700__ $$aPlesa, Ana-Catalina 
000005258 700__ $$aRivoldini, Attilio
000005258 700__ $$aStanley, Sabine
000005258 773__ $$tAGU 2020 Fall Meeting, Virtual
000005258 8560_ $$fattilio.rivoldini@observatoire.be
000005258 980__ $$aCPOSTER