2-DIMENSIONAL CONVECTIVE TURBULENCE

We show that 2D E X B ionospheric turbulence of the electron density i n the equatorial electrojet is isomorphic to the viscous convection of an ordinary fluid in a porous medium due to temperature gradients. Nu merical simulations reveal the strong anisotropy in the turbulence, wh ich consists of rising hot bubbles and falling cool bubbles. These bub bles break up into fingers leading to the formation of stable shear fl ows. After reaching a quasisteady state, the omnidirectional energy sp ectrum approaches a k(-2) behavior, rather than k(-5/3) as expected fr om isotropic turbulence. Physical mechanisms that lead to anisotropy a re analyzed.