ESA study paves the way for a better understanding of space weather   Northern lights caused by charged particles entering the atmosphere - an example of space weather. These charged particles also heat the upper atmosphere, increasing the air density and the drag on satellites.   The frames of this animation are 90 minutes apart and each shows approximately one orbit of CHAMP data (the coloured band), overlaid on a coloured grid with contours of NRLMSISE-00 model densities for the same time and altitude. The graph on the bottom-right shows levels of solar activity (red) and geomagnetic activity (blue). A series of three geomagnetic storms, which increase in intensity, occur during this period (the blue peaks). During the storms, the CHAMP data shows very large peaks in the density, especially at high latitudes. These increases in energy are the result of charged particles entering the atmosphere, which also caused some beautiful displays of the Northern Lights at the time.   Graph showing how the density of the atmosphere varies with altitude and the approximate altitudes of missions carrying accelerometers. The graph is based on the NRLMSISE-00 model.   Graph showing how the temperature of the atmosphere changes with altitude. The different atmospheric layers (troposphere, stratosphere, mesosphere and thermosphere) are defined by alternating increases and decreases in temperature. The temperature reaches a maximum value in the thermosphere. The graph is based on the NRLMSISE-00 model.   Geometry model of the CHAMP satellite, as seen from the direction of incoming atmospheric particles. This geometry model has been used in satellite aerodynamic calculations required for deriving density and wind from accelerometer measurements. The model was created with ANGARA software, which was previously designed and built for ESA by HTG-Hypersonic Technology Goettingen. The elongated shape and the many protruding elements on the CHAMP satellite, such as antennas, baffles and the large boom, are complicating factors in the aerodynamic force calculations. Release date: 13 January 2011