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Table 1 Magnetic latitude boundaries for each of the five regions de-noised separately using PCA

From: Geomagnetic Virtual Observatories: monitoring geomagnetic secular variation with the Swarm satellites

Region Magnetic latitude N K Variance in kth PC (%) Total (%)
Polar North \(70^{\circ } \le \lambda _m \le 90^{\circ }\) 11 4 32.7, 28.6, 16.7, 5.3 83.3
Auroral North \(50^{\circ } \le \lambda _m < 70^{\circ }\) 30 3 68.6, 7.8, 6.3 82.7
Low/Mid Lats \(-50^{\circ } \le \lambda _m < 50^{\circ }\) 216 4 69.3, 9.3, 5.2, 3.9 87.7
Auroral South \(-70^{\circ } \le \lambda _m < -50^{\circ }\) 33 3 61.8, 10.5, 5.9 78.2
Polar South \(-90^{\circ } \le \lambda _m < -70^{\circ }\) 10 4 30.7, 24.1, 15.3, 13.0 83.1
  1. The number (N) of GVOs per region, the number (K) of PCs removed during each analysis, the percentage variance accounted for by each of the K PCs and the total percentage variance removed