Recent studies from the Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight;Banerdt et al., 2020) FluxGate (IFG) measurements (Banfield et al., 2019) have greatly enhanced our understanding of the magnetic field at the Martian surface from both internal and external sources. The magnetic field amplitude at InSight landing site was found to be about 2,000 nT, that is, ∼10 times stronger than previously predicted by satellite-based models (Johnson et al., 2020). The time-varying magnetic field reported at InSight landing site has provided further information about external magnetic field sources such as the ionospheric dynamo process and the electric current sheet (

It is well known that the solar quiet daily geomagnetic variation (Sq) at mid-low latitudes primarily originates from the dayside ionospheric E-region dynamo (Matsushita, 1967;Forbes & Lindzen, 1976;Richmond, 1979;Yamazaki & Maute, 2017). According to the classical dynamo theory, the distribution of the geomagnetic field, the tidal wind, and the ionospheric conductivity control the behavior of the Sq type variation (Campbell, 1982). In particular, the geomagnetic field not only modulates the conductivity through its dependence on the electron and ion gyrofrequencies but also controls the dynamo electric field (Le Sager & Huang, 2002;Stening, 1971;Takeda, 1996). The modulation on the conductivity is mainly through the change in the gyrofrequencies of the electrons and ions in the ionospheric dynamo region. At the regions with weaker geomagnetic field strength, such as the South Atlantic Ocean anomaly region (SAA), both the electron and ion gyrofrequencies are lower than those at other regions. The lower boundary of the dynamo region, which is defined by the altitude where the electron gyrofrequency is equal to the electron-neutral collision frequency, is higher at the SAA region. This is also the case at the upper boundary, which is defined by the altitude where the ion gyrofrequency is equal to the ion-neutral collision frequency. The dynamo region will upward shift at the SAA region, and thus they are located at altitudes where the electron density is larger. This upward shift causes the enhancement of both the height integrated Pedersen (Σ P ) and Hall conductivities (Σ H ). Using a numerical calculation, Takeda (1996) estimated the height of integrated Pedersen and Hall conductivities for different geomagnetic field strengths. He found that the Σ P and Σ H are 42 and 26 times stronger at the regions with 10% of the normal geomagnetic field strength, respectively. As a consequence of these factors, the Sq electric current systems show a remarkable dependence on season, solar activity,