The award recognizes Sonnerup's ongoing space physics research on the magnetopause, a narrow layer in space sandwiched between the earth's magnetic field and the sun's plasma emissions or solar wind. His research aims to better understand how mass, momentum and energy from the solar wind move through the magnetopause. By understanding processes in the magnetopause region, we might someday be able to better predict and prepare for the effects of space weather. The goal of studies like this is to enable scientists to predict how severe space weather, caused by explosive mass ejections from the sun, make themselves felt near earth. These satellites may be damaged by intense particle radiation or unexpected changes in the magnetic field during storms.
Radiation is also a hazard for astronauts and for flight crews on high-flying aircraft.
Disruption of radio communications and radar systems, as well as power grid surges and outages, may result from space storms. The brilliant displays of northern lights, seen in northern New England, also occur during space storms. The solar wind is a mixture of ions, mainly protons, and electrons in equal numbers. This gas is extremely thin, but it moves at high speed and has the momentum to compress and strongly distort the earth's magnetic field. Gathering data from the magnetopause is tricky, however.