Following her degree she joined the Met Office, where she became a Senior Scientist in the dynamical meteorology section. Her research focussed on clouds and their interactions with the rest of the atmosphere, and she pioneered new ways to represent clouds in weather forecast and climate models.[1][2] In 1985 she left the Met Office and, after a year at the European Centre for Medium-Range Weather Forecasts (ECMWF)[3] in Reading, UK, Dame Julia moved in 1986 to the National Center for Atmospheric Research (NCAR) in the USA. While at NCAR she was awarded in 1989 a PhD in atmospheric physics from the University of Bristol, for a thesis completed through a series of published papers.[13]