German Aerospace Center (DLR) Institute of Communications and Navigation Neustrelitz , Germany

1. New capabilities of 3D ionosphere/plasmasphere electron density reconstructions and associated space weather studies utilizing the unique SWARM satellite constellation Workshop DFG-SPP Dynamic Earth 03.- 04.07.2014 Mainul Hoque, TatjanaGerzen, Hiroatsu Sato and Norbert Jakowski German Aerospace Center (DLR) Institute of Communications andNavigation Neustrelitz, Germany

2. Motivation • GNSS navigationdatafrom LEO satellitesenable the reconstructionof the electrondensitydistributionof the topsideionosphere /plasmasphere • DLR NZ routinely reconstructs the topside ionosphere & plasmasphere electron density distribution onboard CHAMP & GRACE satellites since more than one decade for space weather monitoring and associated research of the geo-plasma. • SWARM constellationprovides a uniqueopportunitytoenhancetheseactivities. Comparisonwith IMAGE data [Gerzen et al. 2014]

3. Enhanced database • SWARM 3 satelliteconstellationoffershigh resolution ionosphere/ plasmasphere reconstruction in different orbital planesandheights ACE/DSCOVR reception + support by DLR Neustrelitz Directaccessof ACE dataallowsmonitoringpasmasphereand solar wind parameters in near real time Schematic view of SWARM GNSS measurement geometry

4. Advanced approach for topside ionosphere & plasmasphere electron density modelling usingspace- andground-basedmulti-sensorsdatafrom • SWARM 3 satellite constellation GPS and Langmuir probe • other LEO satellites (GRACE + COSMIC) including IRO data • GNSS groundstation • Verticalsounding • ACE IMF and solar wind parameters Reconstructed 3D ionosphere (http://IMPC.dlr.de ) • Our Goals • High quality and resolution reconstruction of the topside ionosphere & plasmasphere • Plasmapause location associated with plasmasphere compression during space weather events characterized by ACE data • Study the occurrence and features of plasma bubble at the SWARM satellites altitude • SWARM topside ionosphere gradients detection and modelling [Gerzen et al. 2013]

5. Plasmapause reconstruction using SWARM 3 satelliteconstellation Comparisonwith IMAGE datashowsthatthe limited CHAMP data coverage over the polar regions and the degraded GPS observation geometry are not sufficient to localize plasmapause accurately [Gerzen et al. 2013]. • The SWARM 3 satelliteconstellationprovides larger datacoverage. • The electrondensitydistributionandplasmapause location can be deduced from the cross correlation of the data from SWARM satellites at different altitudes. CHAMP – IMAGE satellite constellation IMAGE T=2 Yrs. T= 0 GPS CHAMP

6. Plasmapause compression in dependency on solar wind Combining the SWARM three satellite topside ionosphere/plasmasphere reconstruction with the ACE IMF and solar wind data the plasmapause radial position changes with the solar wind speed can be investigated. [Børve et. al. 2011] swaciweb.dlr.de/

7. Study the occurrence and features of plasma structures The potential of CHAMP derived reconstructions for detection and study of a plasma density enhancement at mid-latitudes during a storm [Park et al. 2012]. • 3 SWARM satellites flying time-shifted at different altitudes provide significant more information for plasma structures studies. [Park et al. 2012] • Detectionand study features of plasma bubble and blob structures around the SWARM satellites altitude Fig. 6: Plasma density distribution derived from CHAMP TEC data assimilation

8. SWARM topside ionosphere gradients detection and modelling Ionosphere bubble, gradientsdetectionusing SWARM GPS observations. • Topsideionosphere gradientsdetectionandmonitoringusing GPS measurementsonboard 3 SWARM satellites. • Extractfeaturesofthedetectedgradientsfromthe SWARM basedtopsideionosphere/plasmasphere reconstruction.

9. day 02:20 LT 06:00UT day 02:20 LT 09:00UT Capabilitytostudyionospheric perturbations - Storm on 8November 2004 Comparison of subsequent reconstructions of the 3D electron density structure during the ionospheric storm on 8 November 2004 in comparison with plots of percentage deviations from corresponding medians (Dne/ne • 100%). [Jakowski et al. 2007]

10. Capabilitytostudy ionospheric perturbations- Storm on 20 November 2003 • Strong enhancement of ionisation (TEC) at evening/nighttime sector • Probably due to strong zonal plasma convection (no tongue of ionization across the North Pole) • Enhanced plasma density at high latitudes at both hemispheres along field lines (at daytime only at South Pole area) 18 UT 19 UT 20 UT night day night day [Jakowski et al. 2007]

11. Summary • High quality and resolution reconstruction of the topside ionosphere & plasmasphere • Plasmapause location associated with plasmasphere compression during space weather events characterized by ACE data • Study the occurrence and features of plasma bubble at the SWARM satellites altitude • SWARM topside ionosphere gradients detection and modelling

12. References Gerzen T., J. Feltens, N. Jakowski, I. Galkin, R. Denton, B. Reinisch, R. Zandbergen (2014) Validation of plasmasphere electron density reconstructions derived from data on board CHAMP by IMAGE/RPI data, to appear in Adv. in Space Res. Gerzen T., N. Jakowski, V. Wilken, M. M. Hoque (2013) Reconstruction of the ionospheric 3D electron density distribution by assimilation of ionosonde measurements and operational TEC estimations, EGU 2013. J. Park, H. Lühr, N. Jakowski, T. Gerzen, H. Kil, G. Jee, C. Xiong, K. Wook Min, and M. Noja, A long-lived band of plasma density enhancement at mid-latitudes during the 2003 Halloween magnetic storm, J. of Atmosph. and Solar-Ter. Phys., 80, 100-110, 2012. Jakowski, N., V. Wilken, and C. Mayer (2007), Space weather monitoring by GPS measurements on board CHAMP, Space Weather, 5, S08006, doi:10.1029/2006SW000271 S. Børve, H. Sato, H. L. P´ecseli, and J. K. Trulsen (2011) Minute-scale period oscillations of the magnetosphere, Ann. Geophys., 29, 663–671