2:00pm - 2:15pm
The Status of Swarm: from Core to Magnetosphere Three and a Half Years after Launch
European Space Agency
The ESA Earth Observation Swarm satellite mission, a constellation of three satellites to measure the Earth’s magnetic and electric fields as well as the neutral environment, was launched on November 22, 2013. The mission delivers observations that provide new insight into the Earth system by improving our understanding of the Earth’s interior as well as the near Earth electro-magnetic environment. The unprecedented high-accuracy and high spatial resolution measurements of the strength, direction and time variations of the magnetic field, complemented by precise navigation, accelerometer and electric field measurements, provide the required observations to model the various sources of the geomagnetic field.
Swarm is ESA’s fourth Earth Explorer mission This innovative mission is dedicated to identifying and measuring, very precisely, the different magnetic signals that stem from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere – which together form the magnetic field around Earth. Analysing how it changes over time, provides new insights into our planet’s interior and near-Earth environment. This presentation will include the mission status a three and a half years after launch and focus also on the mission objectives, products studies and result. Evidently, the magnetic field behaviour at present indicates that it is as one of the fastest changing variables related to global change. Meanwhile, it is clear that new science beyond the original objectives of Swarm has already emerged. The presentation will report on these aspects and what can be expected in the near future.
2:15pm - 2:30pm
Geomagnetic Field Modeling Efforts with Swarm – What is Possible with the Present Data and What are Future Opportunities?
Technical University of Denmark, Denmark
We discuss field modeling efforts based on more than 3 years of Swarm satellite data, with focus on the additional information that is provided by the East-West gradients (approximated by the difference between Swarm Alpha and Charlie) and the North-South gradient (approximated by the along-track first differences of each satellite).
We also present results of experiments concerning the future development of the Swarm constellation mission over the next decade.
2:30pm - 2:45pm
Swarm Instruments Status and Data Quality after Three Years in Operations
1ESA, Esrin, Italy; 2INGV, Italy; 3ESA, Esoc, DE; 4IAPS-INAF, Italy; 5ESA, Estec, NE; 6GMV, Poland
Swarm is a three-satellite ESA Earth Explorer mission with the key objectives of studying the geomagnetic field with unprecedented accuracy and the electrodynamics of the Earth’s ionosphere. The three spacecraft have been launched in November 2013. Following three years of mission exploitation, this presentation provides an update on the instruments status and data quality.
2:45pm - 3:00pm
Swarm Flight Dynamics Operations Experiences and Mission Analysis
1ESA/ESOC, Germany; 2CS GmbH at ESA/ESOC, Germany; 3SCISYS Deutschland GmbH at ESA/ESOC, Germany
The three satellites of ESA's magnetic field mission Swarm were launched into a common low Earth circular orbit in November 2013. Since completion of the orbit acquisition phase in April 2014 one satellite (B) is flying in a higher orbit with an inclination of 87.8 deg and an altitude decaying from 520 km. The other two satellites (A/C) form the lower pair with an initial altitude of 473 km, an inclination of 87.4 deg and an ascending node difference of 1.4 deg.
The paper gives an overview about the observed orbit evolution, the fuel consumption and the constellation maintenance operations which have been performed by the Flight Dynamics Divsion at ESA/ESOC. Latest simulation results about the future orbit evolution and mission duration are given for the case where the satellites are left to the natural perturbations.
The orbit evolution is driven by the two major perturbation forces. These are the Earth gravity field causing the rotation of the orbital planes and the atmospheric drag leading to the altitude decay.
The gravity field perturbation is a function of orbit inclination and semi major axis and thus the rotation rate differs between Swarm-B and Swarm-A/C. The resulting observed and predicted absolute and relative rotations are shown. A relative local time difference of 12h in ascending node could be reached in about five years. In these counter rotating orbits Swarm-B frequently crosses above the lower pair satellites.
The altitude decay depends strongly on the solar activity leading to large uncertainties of the predicted mission duration. First the observed altitude evolution will be shown and compared with past predictions. Then the latest simulation results for the future decay of the satellites is given for different cases of future solar activity.
Small differences in drag, mass and attitude drive the constellation maintenance of the lower pair. Gathered experience about the manoeuvre frequency, the corresponding minimum and maximum time differences, instantaneous altitude difference and the fuel consumption will be shared.
In the absence of major orbit changes the fuel consumption is rather small. Most of the fuel is spent for attitude control. In addition fuel has been spent for calibration operations, the constellation maintenance and a few manoeuvres due to conjunctions with space debris. A significant amount of fuel is remaining which can be used to change the orbit and to extend the mission beyond the originally planned mission of four years.
3:00pm - 3:15pm
New Synergistic Opportunities for Magnetosphere-Ionosphere-Thermosphere Coupling Investigations Using Swarm and CASSIOPE e-POP
1University of Calgary, Canada; 2ESRIN, Italy; 3Delft University of Technology, Netherlands; 4Institute de Physique du Globe de Paris, France; 5University of New Brunswick, Canada; 6University of Alberta, Canada; 7Technical University of Denmark, Denmark; 8GFZ German Research Centre for Geosciences, Germany
We present a recent study to identify new synergistic opportunities for magnetosphere-ionosphere-thermosphere (MIT) coupling investigations, by taking advantage of the complementary nature of the orbital (particularly altitude and local time) coverage and unique measurement capabilities of CASSIOPE e-POP, as an added component to the Swarm satellite constellation under European Space Agency’s Third Party Mission programme.
The coordinated operation of the e-POP payload with Swarm, in particular the Magnetic Field (MGF), GPS-receiver-based Attitude, Positioning and Profiling (GAP) and Fast Aurora Imager (FAI) instruments, will enable or enhance a host of new investigations on the Earth’s magnetic field and related current systems, upper atmospheric dynamics, auroral dynamics, and related MIT coupling. These include (a) magnetic field perturbations at high latitudes, specifically their small scale structures, altitude distribution and longitudinal extent; (b) thermospheric density variations, plasma density irregularities, and density forecasts for orbit prediction; and (c) electrodynamics of the auroral arcs and magnetosphere-ionosphere coupling.
These investigations are expected to contribute significantly to two of Swarm’s four primary research objectives, and to advance our fundamental knowledge on MIT coupling and the effects of associated space weather processes on the Earth’s magnetic field and its ionosphere and thermosphere.
3:15pm - 3:35pm
Keynote: Thermosphere-Ionosphere-Magnetosphere Modeling and Validation Efforts Using SWARM, CHAMP, and GOCE Measurements
1University of Michigan, Ann Arbor, MI, United States of America; 2Technical University Delft, Delft, The Netherlands; 3British Antarctic Survey, Cambridge, United Kingdom; 4Wuhan University, Wuhan, China
Space Weather is a term that is used to describe the time-varying conditions in the near-Earth space environment. Some of these conditions can be detrimental to technologies that are either on the surface or in space. For example, when large auroral events occur, significant amounts of energy are added to our upper atmosphere, causing it to heat and expand. This expansion can cause the density at low-Earth orbiting satellite altitudes to sometimes increase by an order of magnitude. These increases are not well modeled and therefore, the resulting changes in satellite trajectories are not well predicted.
As another example, strong currents and electric fields in the upper atmosphere, driven by processes in the magnetosphere, and often associated with the aurora once again, can drive currents in power lines that can overwhelm power transformers. These events have the potential to cause massive power outages in high-latitude countries.
Because of the complexity of the thermosphere-ionosphere-magnetosphere system, it is impossible to predict these types of events without the use of models. Global models of the magnetosphere and ionosphere-thermosphere system are used to predict satellite drag, geomagnetically induced currents, the radiation environment, communication losses, and other space weather driven effects.
While the act of modeling the space environment is an important first step, it is crucial that the models be validated against measurements of the near-Earth space environment. The SWARM mission, as well as many other European led missions that have come before it, have played vital rolls in improving our ability to model space weather and its effects.
In this talk, we will discuss some of the models that are being used to simulate the near-Earth space environment and the validation efforts that have been conducted using some of the data provided by missions such as SWARM, CHAMP, and GOCE. Particularly, we will discuss long-term validation efforts between the Global Ionosphere Thermosphere Model (GITM), the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and GOCE inferred mass densities and winds in the thermosphere as well as global MHD simulations of the Earth’s magnetosphere and efforts to validate the field-aligned currents produced by the models using CHAMP and SWARM data.