From: Spatial gradients of geomagnetic temporal variations causing the instability of inter-station transfer functions
\(m =\) BMT
\(m =\) KAK
\(m =\) KNY
\(m =\) MMB
\({\text{BR}}_{m,x} \left( 1 \right)\)
19.1
23.4
20.6
\({\text{BR}}_{m,x} \left( 2 \right)\)
11.2
8.1
4.9
11.0