  The mean parallel current density evolution equation is presented using
electromagnetic (EM) gyrokinetic equation. There exist two types of intrinsic
current driving mechanisms resulted from EM electron temperature gradient (ETG)
turbulence. The first type is the divergence of residual turbulent flux
including a residual stress-like term and a kinetic stress-like term. The
second type is named as residual turbulent source, which is driven by the
correlation between density and parallel electric field fluctuations. The
intrinsic current density driven by the residual turbulent source is negligible
as compared to that driven by the residual turbulent flux. The ratio of
intrinsic current density driven by EM ETG turbulence to the background
bootstrap current density is estimated. The local intrinsic current density
driven by the residual turbulent flux for mesoscale variation of turbulent flux
can reach about 80% of the bootstrap current density in the core region of ITER
standard scenario, but there is no net intrinsic current on a global scale.
Based on this, the local intrinsic current driven by EM micro-turbulence and
its effects on local modification of the profile of safety factor may be needed
to be carefully taken into account in the future device with high beta_e which
is the ratio between electron pressure to the magnetic pressure.
