As a result of electric field measurements in remote points of the surface layer and analysis of obtained statistical characteristics (structural function, temporal spectra) two typical scales of electric field pulsations are found. The lowest one L0≂20--60 m coincides with an external scale of neutral gas turbulence under fair weather conditions. The highest scale L1>60 m testifies to the existence of long-time electric field perturbations which lead to the anomalous growth of the structural function DE(r) at a distance r>L1. The relation between the scales L0 and L1 depends on the particular experimental conditions. The theoretical model for the function DE(r) has been developed, taking into account the turbulent mixing of charged particles and thermal convection in the surface layer. It is shown that the expression for DE consists of two parts. The first part describes fluctuations caused by the charge separation due to neutral gas turbulent mixing; the second part gives a contribution of large-scale convective cells, which can transfer a volume charge along the Earth's surface. ¿ American Geophysical Union 1994