Daniel N. Baker
The 2019 Hannes Alfvén Medal is awarded to Daniel N. Baker for outstanding, multi-faceted contributions to the near-Earth space plasma environment research and predictions, Earth’s radiation belt environment monitoring, and planetary space plasma studies.
Daniel N. Baker has made seminal scientific discoveries and contributions to the exploration and understanding of the Earth’s plasma and fields environment. He has also been a key player in developing the applied field of space weather. He has excelled in all key areas of Alfvén’s contributions: research above all, but also public policy, education, and administration.
He studied magnetic reconnection as part of the magnetospheric dynamics and developed nonlinear modelling methods to characterise the large-scale dynamic state of the magnetosphere. This led to new understanding of the ways the solar wind drives the near-Earth space environment. He showed that the relativistic electron environment varied with changes in the solar wind as well as with magnetic activity and magnetotail reconnection events. His analysis of the Van Allen Radiation Belt Probes’ data led to the discovery of a third storage ring in the radiation belts, and also to the discovery of the existence of a barrier to the highest-energy electrons.
Baker was one of the first, already in 1987, to recognise that energetic particles penetrating to quite low layers in the atmosphere could affect Earth’s ozone layer. His ideas led to the student satellite project Student Nitric Oxide Explorer. We now know that the nitrogen compounds created by collisions with precipitating energetic particles are also ozone-depleting substances.
Baker’s contributions to planetary science range from his pioneering work with James Van Allen on the Jovian magnetosphere to his more recent work on Mercury. He was among the first to point out that the accelerated electrons in the Hermean environment behave much as they do in the Earth’s magnetosphere, proposing that processes analogous to magnetospheric substorms occur at Mercury.
He was a central actor in the International Solar Terrestrial Physics programme, with the coordination of several satellite missions by space organisations. He served as co-investigator on a large number of space missions, terrestrial and planetary. He has been a hands-on experimenter but, most importantly, he has had a presence in all phases of a mission: concept, management, implementation, operations, data analysis and publication. In this respect, with more than 520 journal papers published, that have received over 18,000 citations, and with an h-index of 75, he has been one of the most prolific writers in the entire discipline.
Baker has been actively promoting space weather research and calling attention with the public. His efforts include chairing national committees on societal and economic impacts of the space weather and the publication in Nature of a paper on the distortion of the Van Allen belts arising from the severe geomagnetic storm in 2003, called the ‘Halloween storm’. He has led several U.S. National Academy studies and reports in this regard. He is one of the few scientists who can grasp scientific research in the context of the social and economic context.
Daniel Baker is a remarkable leader and a true team player. His scientific influence ranges over a number of topics. He has the ability to get people as well as groups to work together toward common goals. His inimitable insights and intuition have brought space science far from where it would be without him.
For all these reasons, he is a worthy recipient of the 2019 EGU Hannes Alfvén Medal.