Y is tangential to the ground at the device's current location and points toward the geomagnetic North Pole.

值是设备当前所处位置与地磁北极的正切值。

youdao

With geomagnetic field model records, several kinds of secular variation of geomagnetic dipole moment and the position of the geomagnetic North Pole during the year 0 ~ 2000 a.

利用地磁场模型资料，计算和分析了公元0 ~ 2000年的地磁场偶极子磁矩和地磁北极位置的长期变化。

youdao

The Geomagnetic pole is the north end of the axis of the geomagnetic field which surrounds the Earth and extends into space as the magnetosphere.

BBC: NEWS | UK | British man scores polar success