Figure 3

Results from stochastic realizations of the anthrax transmission process forced with time-series of active layer depth derived from the data-set of the Lena River delta monitoring site. (a) Model forcing. (b) Example of stochastic model simulation. Median (black line) and 5th–95th percentile bounds (gray-shaded area) of 100 model realizations of daily incidence (in percentage over the total population size H), over 10 years. (c) Box plot of annual cumulative incidence (again, divided by H, in percentage) versus maximum thawing depth. Case 1 (in orange) accounts for a linear relation between \(\eta\) and Z, whereas case 2 (in gray) includes a saturating function, in which \(Z_0=20\) cm (inset). In each box, the central mark indicates the median, the bottom and top edges indicate the 25th and 75th percentiles, and the whiskers extend to the 5th and 95th percentiles of the distribution. Outliers are represented as points in case 1 and as “x” marks in case 2. (d) Temporal sample autocorrelation of yearly infection risk for case 1 (orange) and case 2 (gray). Initial conditions (b,d): \(I(0)=10\) and \(S(0)=H-I(0)\). Parameters values as in Table 2 in the main text. We set \({\overline{R}}_0=2\) and accordingly we derived \(\theta ^{*}=2.8\cdot 10^{-6}\). Other parameters: \(\beta _0=1\), \(\epsilon _{\beta }=1\), \(\eta _0=0.2\).