Figure 3

Thresholds for constructing correlation networks. (a) \(W^{\mathrm{pos}}_{i,j}\) VS \(D_{i,j}\). The results after hourly shuffling are shown by green points. Here, for each pair of nodes i and j, we randomly shuffle the two time series independently with hourly intervals. To make the comparison clearer, the x-axis is limited from 0 to 5 km. The thresholds for constructing network is thus \(W_{\mathrm{min}}=4.2\) and \(D_{\mathrm{max}}=0.91\) (km). (b), (c) The same as (a) but for NT1 and RH2. The corresponding thresholds are \(W_{\mathrm{min}}=4.2\), \(D_{\mathrm{max}}=0.86\) (km) for NT1, and \(W_{\mathrm{min}}=4.3\), \(D_{\mathrm{max}}=0.60\) (km) for RH2. The data is during 26–30 Oct. 2015, \(N=4530\), \(L=900\), and \(\tau _{\mathrm{max}}=150\)