Current distribution within a new meteorological gradient observation tower under direct lightning strike in Shenzhen and spatial electrical field around the tower

Current distribution within a new gradient observation tower has been calculated by finite-difference time-domain (FDTD) method. The current through Metallic stay cables which are designed to reinforce tower body has been take into account. It is found that a large portion of lightning current would be absorbed by stay cables. Ground level electrical field is also given by the calculation. In addition, the influence of tower on background field is addressed when thundercloud exists based on the solution of Laplace static equation.