Paul Roberts made important contributions to the theory of fluid mechanics, particularly when magnetic fields are present and thermal convection occurs, as is the case in astrophysical and geophysical situations. Deserving of special mention are his papers, alone or in collaboration, elucidating the nature of the geomagnetic field, the properties of rotating masses of fluid, the linear and nonlinear theories of thermal instability. He also made notable contributions to the theories of the solar wind and of the origin and behaviour of quantised vortex lines in liquid helium.

Professor Paul Roberts FRS died on 17 November 2022.