The 2012 Julius Bartels Medal is awarded to Michael Lockwood for his outstanding contributions to the understanding of the dynamics of the terrestrial magnetosphere and the coupling between solar variability, magnetospheric and ionospheric processes, and the terrestrial climate.
The significant research contributions that Michael Lockwood has made during his career to date are broad and numerous, but centre in the influence of solar effects on the terrestrial environment. He began his scientific career in the late 1970s in the field of ionospheric physics and worked extensively with both ground- and space-based data sets. The early work, which continues to the present day, concerns the influences of magnetospheric dynamics driven by the solar wind interaction. Lockwood was the first to recognise the signatures of transient magnetopause reconnection in ground-based radar data. In subsequent ground-breaking work he developed means to determine the reconnection rates from studies of ion spectra in the dayside cusp region of the magnetosphere. This work importantly led to his co-development of the paradigm-shifting “expanding and contracting polar cap” model, that provides a conceptual framework within which to consider magnetospheric dynamics. He, his students and co-workers have continued to illuminate this concept with quantitative modeling studies, and to develop it in relation to the substorm cycle. Most recently Lockwood has expanded his activities into consideration of the variability of the Sun on a broad range of time scales, and its influence not only on geomagnetism and the upper atmosphere, but also on possible influences on the Earth’s climate. In particular he has brought statistical rigour to what was until then a highly controversial field tied up with the issue of climate change. His entry into this field was published in Nature in 1999. It showed, using various proxy data sets, that the Sun’s magnetic field has changed significantly over a century. This publication has, thus far, been cited more than 300 times. Since then Lockwood has actively pursued the topic of long-term changes in the Sun and their effect on the Earth using a number of data sets, again characterised by careful statistical analysis. This large, and well received, body of work has proved to be timely given the recent extended solar minimum and the possibility that the Sun is moving towards a new grand minimum. Lockwood’s publication list consists of about 280 scientific articles. According to the ISI data base these have been cited more than 6,500 times. Lockwood’s H-index is 43 (as of August 2011). The impact of these studies has been widely recognised throughout Lockwood’s career. In 1990 he was the recipient of prestigious young scientist awards by both COSPAR (Zeldovich Medal) and URSI (Issac Koga Gold Medal), followed by mid-career awards of the Chapman Medal by the UK Royal Astronomical Society and the Charles Chree Medal and Prize by the UK Institute of Physics. In 2006 he was elected as a Fellow of the Royal Society of London, the highest scientific honour in the UK.