DATA ASSIMILATION FOR THE STUDY OF MAGNETOSPHERE-IONOSPHERE-ATMOSPHERE COUPLING

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State-of-the-art ionospheric imaging techniques use Global Positioning System (GPS) satellite data. In a similar manner to medical imaging, where the patient is examined by X-rays, in ionospheric imaging the upper atmosphere (ionosphere) is examined by radio waves. The next big step for ionospheric imaging is to combine it with models of the ionosphere. The reason to do this is to discover the underlying physics, which we cannot do very well by just looking at the images. We need to link the images to models of winds, solar radiation and electric fields in order to understand what causes the upper atmospheric environment to behave as it does during extreme events called storms. These are not the weather storms we are familiar with but rather these space-weather storms are caused by the bombardment of the outer realms of the atmosphere with particles and radiation from the Sun. The mathematics we need to link the measurements to the models is called data assimilation. Data assimilation has already been strikingly successful in meteorology. The data assimilation to be developed under this grant is for much higher up in the atmosphere (above 100 km) and will be used to investigate the coupling between the neutral and ionized atmosphere and to determine the relationships between ionosphere-atmosphere dynamics and magnetosphere dynamics.