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Interaction between the solar wind and the Earth's magnetosphere isassociated with large-scale currents in the ionosphere at polar latitudes thatflow along magnetic field lines (Birkeland currents) and horizontally. Thesecurrent systems are tightly linked, but their global behaviors are rarelyanalyzed together. In this paper, we present estimates of the average globalBirkeland currents and horizontal ionospheric currents from the same set ofmagnetic field measurements. The magnetic field measurements, from the lowEarth orbiting $\textit{Swarm}$ and CHAMP satellites, are used to co-estimatepoloidal and toroidal parts of the magnetic disturbance field, represented inmagnetic apex coordinates. The use of apex coordinates reduces effects oflongitudinal and hemispheric variations in the Earth's main field. We presentglobal currents from both hemispheres during different sunlight conditions. Theresults show that the Birkeland currents vary with the conductivity, whichdepends most strongly on solar EUV emissions on the dayside and on particleprecipitation at pre-midnight magnetic local times. In sunlight, the horizontalequivalent current flows in two cells, resembling an opposite ionosphericconvection pattern, which implies that it is dominated by Hall currents. Bycombining the Birkeland current maps and the equivalent current, we are able tocalculate the total horizontal current, without any assumptions about theconductivity. We show that the total horizontal current is close to zero in thepolar cap when it is dark. That implies that the equivalent current, which issensed by ground magnetometers, is largely canceled by the horizontal closureof the Birkeland currents.

Sunlight effects on the 3D polar current system determined from low Earth orbit measurements