Dominant two-dimensional solar wind turbulence with implications for cosmic ray transport

Two new methods for distinguishing two-dimensional(2D) turbulence from slab turbulence are applied to Relies magnetometer data. Two-component models with varying slab and 2D ingredients are considered. Both methods indicate that solar wind magnetic turbulence possesses a dominant (similar to 85 % by energy) 2D component. The presence of such a large 2D component provides a natural solution to the long-standing problem of ''too small'' cosmic ray mean free paths derived from quasilinear scattering theory when using the slab model.