5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F PRELIMINARY NEW VERSION OF THE COMPREHENSIVE INVERSION (CI) LEVEL-2 PRODUCTS Terence J Sabaka, Lars Tøffner-Clausen, Nils Olsen

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Crustal field of CI inversion (MLI) as of May 2015

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Crustal field of CI inversion (MLI) New version (preliminary) How has this new CI model been obtained ?

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Data selection and data use Data selection 1 Hz data downsampled to 15 sec data |dDst/dt| < 3 nT/hr Kp ≤3 0 East-West/North-South (EW/NS) scalar sums/differences (s/d) for all local times and all latitudes EW/NS vector s/d for all local times and |QD lat| < 55° Scalar data nightside for all latitudes Vector data nightside for |QD lat| < 55° No observatory data

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Model Parameterization (1) Degree/order (d/o) 90 static (core+crustal) field d/o 13 linear SV d/o 1 magnetospheric/induced fields in 1 hr bins "usual" CI ionospheric parameterization accounting for 3D induction via Q-matrices d/o 36 M 2 tidal field (period hrs)

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Model Parameterization (2) (Nominal) core determined by all data except low-latitude dayside (Nominal) crust determined by all field data and all difference data except low-latitude dayside Ionosphere determined by all data Magnetosphere/induced determined by all data (Nominal) M 2 determined (mostly) by all difference data

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Major differences from "old" CI model Direct Huber weighting of s/d rather than formal covariance propagation from scalar or vector constituents Component-only s/d used (like SIFM+) rather than full covariant forms The addition of scalar/vector data to s/d data rather than only s/d data No vector data for |QD lat| > 55° rather than using vector at all latitudes (no toroidal field estimated yet) Day as well as night data for crust and M2 rather than nightside only M 2 determined mostly by gradient data Core field now varies linearly rather than quadratically

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Secular Variation of CI inversion (MCO) Note: ”new CI” uses linear SV, whereas ”old CI” estimates a quadratic SV

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Crustal field of CI inversion (MLI)

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Ionospheric Current Function March Equinox

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F M2 Tidal Field 18 months of Swarm data allows for an astonishing determination of the M 2 tidal signal, comparable to what has been obtained using 10 years of CHAMP data (at lower altitude) |B r | of M 2 tide Model prediction CM5 (CHAMP) CI (Swarm) Sabaka et al., GJI (2015)Sabaka et al., in preparation for GRL

5 th Swarm Data Quality Workshop 7 – 10 September 2015IPG Paris/F Conclusions New version of CI model parts derived MCO: core field MLI: crustal field MIO: ionosphereic “Sq” contribution MMA: magnetospheric and induced fields Major improvement compared to version 01, in particular of the crustal field model Further tests will be performed within the next weeks, then (probably) release of new CI chain models