A new solar signal: Average maximum sunspot magnetic fields independent of activity cycle

Over the past 5 years, 2010 to April 2015, we observed 4176 sunspot umbrae in the infrared (IR) to measure maximum magnetic field strengths from the Zeeman splitting of Fe 15,648.5 angstrom. Herein we distinguish "field strengths" from "field flux." Field strengths range from 1500 G in pores to 3500+ in large spots. We made one observation per spot per observing day, ignoring spot size. We show that in the IR no activity cycle dependence on average maximum field strength (2070 +/- 20 G) has been found. A similar analysis of 17,450 spots observed in space by the Helioseismic and Magnetic Imager reveals a similar cycle independence (2050 +/- 0.18 G). We conclude that the average maximum umbral fields are constant with time and independent of the activity cycle within our time coverage.