Summary of part of L2 session Tools e.g. for data selection Products, including models Mostly based on magnetic data Both dedicated and comprehensive models Validation Enhancing return from mission

Quiet time definition Magnetosphere-ionosphere system reconfigures in 10-20 minutes Use SUPERMAG vector data to quantify external field SMDL characterises field, value in nT Quiet time – about 50% data overlap with definition used by Nils Olsen for data selection

Testing SUPERMAG definition Compare with previous CHAOS model Use SMDL to select quiet time data Same amount of data at high latitudes Same amount at mid/low latitudes, and ± 20% Fit as good as or better than for CHAOS (e.g. < 2nT rms misfit to Bϕ) Larger residuals near poles though overall misfit the same

IBI, TEC and FAC FAC and ionospheric radial currents: good agreement between satellites, and between original and mapped data Also undertook in-orbit comparison Comparison between TEC from GPS and electron density measured by Langmuir probe Obtain VTEC from slant TEC – reasonable agreement with electron density Ionospheric bubble indices – investigated seasonal variations Some ionospheric bubbles don’t have a magnetic signature – use electron density instead

FAC – Swarm A, B, and C High-Latitude (01 May 2014 – 31 May 2015) Northern Hemisphere Southern Hemisphere Swarm A Swarm B Swarm C

TEC: Vertical TEC & Electron Density Swarm A Swarm B Swarm C VTEC Ne Statistical Distribution of VTEC and Ne: good agreement

IBI: Seasonal Variations (18-04 MLT) Swarm A Swarm B Swarm C Event detection threshold = 0.15 nT December Solstice Equinox June Solstice

Ionospheric irregularity index based on plasma density IBI and Ne (constant and variable) indices Both: use high-pass filter IBI Index: constant threshold on magnetic field Ne Index: threshold on density Ne Index Constant threshold: not yet sufficient for quantitative bubble description Variable threshold Better coincidence with plasma density maximum: enhanced symmetry about the equator sensitive to data quality New approach is necessary direct detection of depletions and enhancements (work in progress) Preliminary results of the new approach

Dedicated core field model Based on GRIMM methodology No observatory data Data selection went well beyond using data flags SV agrees with other models to degree 10 Euler angles (estimated from quaternions) show LT dependencies

Dedicated lithospheric field model Several models investigated for removing core field – none perfect Some along-track filtering, resulting in slight loss of power visible in power spectrum comparisons Developed new orbit filtering based on similar track recognition Included gradient data in inversion Problems near poles – FACs? Good resolution to degree ~75

PRESENTATION AND VALIDATION OF THE DIFI L2 PRODUCT First DIFI model released to ESA on July 24, 2015 Second DIFI model calculated from satellite data until July 2015 and with new Q matrix based on more recent 1-D conductivity profile (Puethe et al.) Change of Q matrix has a (very) small effect on the model Overall performance of the DIFI chain is close to the requirement DIFI and CI models have noticeable differences (but CI soon to be updated) DIFI, Spring (Apr 1) Equivalent current function of the ionospheric primary currents

Ocean tides Comparison with numerical model Used residual night-time data, CHAMP and Swarm Modelled to degree and order 40 Tidal periods imposed Investigated M2, S2, K1 and N2 Some non-physical features (signal on land) Some amplitudes too big

Conductivity

Comprehensive modelling Improved lithospheric field in latest version Described how model was obtained, although not clear why it is an improvement Scalar and vector sums and differences used (restrictions on use of vector s/d) Definition of M2 as good from 18 months of Swarm as 10 years of CHAMP Ionospheric field over-regularised

Time-variable gravity field from Swarm GPSR data Aleš Bezděk Josef Sebera Jaroslav Klokočník Astronomical Institute, Czech Academy of Sciences, Czech Republic Swarm 5th Data Quality Workshop, Institut de Physique du Globe de Paris, France, 7 – 10 September 2015

GPS monthly solutions: GRACE A/B & Swarm KBR monthlies: CSR and GFZ GPS monthlies: GRACE A/B (2004-2013) GPS monthlies: Swarm (12/2013-3/2015) Time series of GRACE A/B GPS-based monthly solutions is successfully continued by Swarm both seasonal and secular variations Note: this is mm precision in all data, transformations & background models Swarm GPS orbits are accurate enough to track the mm-level time-variable gravity signal Other groups (ITSG, AIUB) obtained similar results by using different inversion methods Grace A/B: Institute of Geodesy (IfG), Graz University of Technology; Swarm monthly solutions: TU Delft

Validation Cross-validation between comprehensive and dedicated models Compare with auxiliary models (e.g. IGRF) Compare with observatory data

BGS Validation Summary The purpose is primarily to: ensure no grievous errors give confidence to ESA and users products have been independently verified Validation procedure is active and effective Products deemed valid and suitable for release HUA b) (and c)) is key. BOU AUX_OBS_2_ residuals; Dedicated MIO models

Enhancing return Add-ons and improvements to existing products Improvements to processing and modelling chains New products Lots of possible examples cited by Nils