Abstract
The results of two-dimensional (2D) numerical simulation of single positive streamer development in atmospheric air in sphere - plane electrode configuration are presented. Correlation of streamer parameters with sphere radius and applied voltage U is revealed. The values of the electric field at the streamer head and in the channel are shown to be almost independent of and U and equal to 150 - 180 and correspondingly. Streamer velocity and radial dimensions linearly increase with U, the coefficient in these linear relations being independent of . Comparison of the results obtained by 2D modelling and in the frame of the commonly used 1D (or quasi-2D) models is made.