The term “space weather” deals with the dynamic conditions in the Earth’s outer space environment including physical processes on the Sun. The strongest disturbances of the space environment are primarily caused by coronal mass ejections (CMEs). CMEs are huge clouds of magnetized plasma and may lead to perturbations of electronic devices. If the CME is Earth- directed, it may result in severe disruptions of the technical infrastructure on Earth and in space (satellites). CMEs can interrupt navigation and communication services or even be the trigger for the loss of complete electricity grids (Quebec 1989, Malmö 2003). In today’s modern society, with steadily increasing technology, it is of utmost importance to recognize and face up to the space weather threat. Hence, the goal of the project SWEETS is to make a sustainable contribution to the subject of space weather.
The project focuses on the development of a forecasting model, to predict the expected impact of solar events on satellites at different altitudes. For the novel approach to estimate mass densities of the upper Earth’s atmosphere we will incorporate scientific data, such as kinematic orbit information and accelerometer measurements, from a wide variety of satellites (e.g. SWARM A-C, TerraSAR-X, Tandem-X, CHAMP, GRACE, GRACE-FO, Cryosat-2, Sentinel 1-2, …). Thus, the analysis will be based on neutral mass densities deduced from kinematic orbit information and, if existing, in-situ measurements of on-board accelerometers. Since all these satellites are orbiting at different altitudes between 300-800km, a tomography of the upper Earth’s atmosphere is feasible and the impact of a solar event on a satellite can be estimated as a function of its orbital altitude.
Through a joint analysis and evaluation of solar wind plasma and magnetic field data, we propose to predict thermospheric density increases and associated satellite orbit decay rates with a lead time of up to one hour. To successfully accomplish the proposed tasks, project SWEETS is based on an interdisciplinary cooperation, involving the (space) geodetic and the astrophysical communities.
This project is funded within the Austrian Space Applications Program (ASAP) Phase XVI by the Austrian Research Promotion Agency (FFG).