## 3 Wenchuan EQ Analysis and Discussion
### Results and Discussion
#### 3.2.2 Simulation Results and Discussion  
From the previous work, the variation of the ionization rate with height due to radon was given as \(Q=Q_{\alpha}+Q_{\beta}\). In this model, the mobility \(b_{\pm}\) of positive and negative ions is set to \(2.5\times 10^{-4}\) and \(2.2\times 10^{-4}\) m\({}^{2}\cdot(\cdot\)s\()^{-1}\)[28], respectively, and the ion recombination coefficient \(\alpha\) is set to \(1.6\times 10^{-12}\). For the turbulent diffusion coefficient \(D_{t}(z)=(Kz+\gamma)/(z+\beta)\), where \(\beta\) is set to \(10\) m, \(\gamma\) is set to \(5\times 10^{-5}\) m\({}^{3}\cdot\)s\({}^{-1}\) and the strong turbulence coefficient K is set to \(5\) m\({}^{2}\cdot\)s\({}^{-1}\)[21]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Altitude/m** & \begin{tabular}{c} **Average** \\ **Energy De-** \\ **position/keV** \\ \end{tabular} & \begin{tabular}{c} **Simulation** \\ **Number** \\ \end{tabular} & \
\begin{tabular}{c} **Total Energy** \\ **Deposi-** \\ **tion/eV** \\ \end{tabular} &
\begin{tabular}{c} **Ion Pairs** \\ **Rate/cm\({}^{3}\cdot\)s** \\ \end{tabular} \\ \hline
10 & 462.855 & \(4.27\times 10^{9}\) & \(9.89\times 10^{11}\) & \(2.93\times 10^{10}\) & 103.45 \\
20 & 462.958 & \(4.25\times 10^{9}\) & \(9.85\times 10^{11}\) & \(2.91\times 10^{10}\) & 103.04 \\
30 & 462.936 & \(4.24\times 10^{9}\) & \(9.80\times 10^{11}\) & \(2.90\times 10^{10}\) & 102.59 \\
40 & 462.963 & \(4.22\times 10^{9}\) & \(9.76\times 10^{11}\) & \(2.89\times 10^{10}\) & 102.17 \\
50 & 462.893 & \(4.20\times 10^{9}\) & \(9.72\times 10^{11}\) & \(2.88\times 10^{10}\) & 101.72 \\
60 & 462.878 & \(4.18\times 10^{9}\) & \(9.68\times 10^{11}\) & \(2.86\times 10^{10}\) & 101.28 \\
70 & 462.954 & \(4.16\times 10^{9}\) & \(9.64\times 10^{11}\) & \(2.85\times 10^{10}\) & 100.87 \\
80 & 462.938 & \(4.15\times 10^{9}\) & \(9.60\times 10^{11}\) & \(2.84\times 10^{10}\) & 100.44 \\
90 & 462.892 & \(4.13\times 10^{9}\) & \(9.56\times 10^{11}\) & \(2.83\times 10^{10}\) & 100 \\
100 & 462.978 & \(4.11\times 10^{9}\) & \(9.52\times 10^{11}\) & \(2.82\times 10^{10}\) & 99.59 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Beta particle simulation parameters and results. Figure 6: (a) Alpha particle simulation data with the best fit. (b) Alpha particle simulation data with the best fit. For the set of partial differential Equation (4), the boundary conditions near the Earth's surface were considered as:  
\[n_{+}(z=0)=n_{-}(z=0)=450\;\mathrm{cm}^{-3},n_{1}(10)=n_{2}(10)=(Q(10)/\alpha)^{1/2} \tag{8}\]  
\[E(10)=\frac{j_{0}}{\lambda_{10}},\lambda_{10}=e\times(b_{+}n_{+}(10)+b_{-}n_{-} (10)) \tag{9}\]  
In Equation (8), \(j_{0}\) is the current density at \(z=0\). For the Wenchuan EQ, [PERSON] et al. developed a model for the piezoelectric effect in rocks and have calculated a current density of \(I_{rock}\) = 500 nA\(\cdot\)m\({}^{-2}\) for an EQ fault area of \(A_{rock}\) = 200 \(\times\) 30 km\({}^{2}\)[29]. The total current input to the atmosphere equals the current output from rocks. \[I_{air}=A_{air}\times J_{0}=I_{rock}=A_{rock}\times J_{rock} \tag{10}\]  
The electromagnetic field parameters of a large area of China were abnormal before the Wenchuan EQ. Abnormal electromagnetic signals were observed at the Gao Bei station in Hebei Province, 1440 km from the epicenter, on May 9, three days before the main EQ. Electromagnetic anomalies were also observed at the Qingxian station in Hebei province, 1439 km from the epicenter, and at Ningjin county in Hebei province, 1241 km from the epicenter. However, there was no electromagnetic signal anomaly observed in Sanhe County, Hebei Province, 1541 km from the epicenter [30]. Thus, it was assumed that the area of the pre-EQ air anomaly region A = 1440 \(\times\) 1440 km\({}^{2}\) calculated by Equation (9) yields \(J_{0}\approx 1.5\) nA. The partial differential Equation (4) was solved mathematically by the boundary conditions given for the Wenchuan EQ.