Matthew Penn and William Livingston, observing the Zeeman spliting of the 1565 nanometer infrared neutral iron line, report in:
an 11 year decreasing trend in the sunspot magnetic field strength.
They used the NSO Kitt Peak McMath-Pierce telescope.
Extrapolating the trend means virtually no sunspots in cycle 25 (we are at the beginning of cycle 24) !!
Are we headed to another 70 year long Maunder minimum ?
They used the NSO Kitt Peak McMath-Pierce telescope.
Extrapolating the trend means virtually no sunspots in cycle 25 (we are at the beginning of cycle 24) !!
Are we headed to another 70 year long Maunder minimum ?
