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An energy extracting black hole magnetosphere can be defined by the locationof its inner Alfv\'{e}n surface, which determines the rate of black hole energyextraction along a given magnetic field line. We study how the location of theinner Alfv\'{e}n surface can modify the structure of energy extracting blackhole magnetospheres in the force-free limit. Hundreds of magnetospheres arenumerically computed via a general relativistic extension of the Newtonianmagnetofrictional method for a full range of black hole spins and flowparameters. We find that jet-like structures naturally form very close to thehorizon for Alfv\'{e}n surfaces near the boundary of the ergosphere and thatenergy is extracted towards the equatorial plane for Alfv\'{e}n surfaces closeto the horizon. This suggests that two broad classes of energy extracting blackhole magnetospheres might exist; those that transmit extracted energy directlyto distant observers, and those that transmit extracted energy to nearbyaccreting matter. Applied to transient high energy phenomena, we find that theymight also differ in timescale by a factor of 20 or more.

Effects of Inner Alfv\'en Surface Location on Black Hole Energy Extraction in the Limit of a Force-Free Magnetosphere