Fig. 2.From: Secular trend of geomagnetic elements in the Indian region(a) Observed annual mean values of D, H, and Z, for quiet days at Alibag from 1921 to 2009, together with their best-fitting curves. (b) Observed monthly mean values of D, H, and Z, for all days at Alibag from 1921 to 2009, together with their best-fitting curves.Back to article page