Assuming time stationarity of the one‐particle distribution functionfon the scale of the bounce motion of particles in a magnetic fieldB, we expand the Vlasov equation throughO(ϵ) in the adiabatic parameter ϵ, which is the ratio of particle gyroradius to scale length of the magnetic field. Sincefis directly proportional to particle fluxdΦ/dWdΩ differential in kinetic energyWand solid angle Ω,fis in principle measurable in space experiments, and our analysis is tailored to be explicitly applicable to space problems. ToO(1),fis gyrotropic; its first velocity moment is (if nonvanishing) parallel toB, and hence macroscopic parallel flow is included in this term. TheO(ϵ) contribution is nongyrotropic, and macroscopic flow perpendicular toBplus additional parallel flow results from these terms. The degree of nongyrotropy and hence the amount of cross‐field macroscopic flow depend on the perpendicular component of the electric fieldE, on curvature and shear in the magnetic field, and on the spatial gradient ▽f0, pitch angle derivative ∂f0/∂δ, and speed derivative ∂f0/∂υ of the lowest‐order distribution functionf0. We also show that the usual expression for the electric fieldE, which produces plasma corotation in an axisymmetric system such as a dipole, also holds for any nonaxisymmetric but rigidly rotating magnetic field pattern, provided the observed magnetic field is used in pl