Jeffrey M. Forbes

The 2016 Julius Bartels Medal is awarded to Jeffrey M. Forbes for his outstanding contributions to the understanding of atmospheric tides and their impact on upper atmosphere and ionosphere space weather.

Jeffrey Forbes is best known for his theoretical studies of atmospheric tides and their effects on ionospheric electrodynamics. From the late 1970s on, when he extended the work of Chapman and Lindzen into a framework that is still at the core of today’s numerical tidal models, he has been the leader in discovering major processes that occur within Earth’s thermosphere-ionosphere-magnetosphere system, and he extended this knowledge to the study of other terrestrial planets, e.g., Mars and Venus. His work on nonlinear tide interactions includes a substantial contribution to the explanation of enhanced lunar tides in response to sudden stratospheric warming events. Most notably, Forbes was among the first to realise that meteorological events in the lower atmosphere, such as atmospheric tides forced by latent heat release in large-scale deep convective systems, have a considerable impact on the global structure and variability of the ionospheric E- and F-regions. This paradigm shift, that ‘space weather’ of the global ionosphere-thermosphere system is not only driven by the solar wind and ultraviolet radiation but also responds to meteorological events through atmospheric waves, is undoubtedly one of the major breakthroughs in solar-terrestrial physics in the past decade. Forbes’ more recent contributions are focused on unravelling the complex chain of interacting dynamical, chemical, and electrodynamical processes from various satellite observations to fill the gaps in our current understanding and ultimately improve the numerical models capable of predicting ‘space weather’, an important task for a technological society. The range and volume of Forbes’ achievements to date may also be judged from his total of about 250 publications in the international refereed literature and his still steadily rising citation rate, reaching an H-index of 48 in 2015. Awarding the Julius-Bartels Medal to Jeffrey Forbes is particularly appropriate given that his contributions have been in a field so closely allied to the scientific interests of Julius Bartels.