On the Use of Modified Taylor Diagrams to Compare Ionospheric Models Sean Elvidge, Matthew Angling November 20 th, 2014

MODIFIED TAYLOR DIAGRAMS Construction of

3 A

4 Pearson’s r correlation (R) A

5 A

6 A Models should ‘aim’ to be next to Observed marker

7 A

8 A

MODIFIED TAYLOR DIAGRAMS Example

10 OBSABCD Std. Dev Corr Bias Error Std. Dev RMS

11 OBSABCD Std. Dev Corr Bias Error Std. Dev RMS

MODEL COMPARISON Test Scenario

IRI-2007 is the 2007 version of the International Reference Ionosphere, the international standard. GITM is the Global Ionosphere Thermosphere Model from the University of Michigan, USA. TIE-GCM is the Thermosphere Ionosphere Electrodynamics General Circulation model from NCAR, Boulder, USA. EDAM is the Electron Density Assimilative Model from QinetiQ, UK. GPSII is the NorthWest Research Associates, USA model. mNeQuick is the data ingestion version of NeQuick, from ICTP and IGAM. Models

Tested over September Assimilated ionosonde data from Grahamstown in the Republic of South Africa (RSA). Assimilated GNSS data from mid Sub-Saharan Africa. Compared the models output to data from the other three ionosondes in RSA, Hermanus, Louisvale and Madimbo. Full results published in Radio Science. Just presenting the Hermanus results here. Image from ISES Regional Warning Centre for Africa. Test Scenario

MODEL COMPARISON Test Results

Conclusions Modified Taylor diagrams have been developed to extend Taylor diagrams to show:  Model bias,  Standard deviation of errors,  Mean square error. McNamara, L. F., M. J. Angling, S. Elvidge, S. V Fridman, M. A. Hausman, L. J. Nickisch, L.-A. A. McKinnell, and A. H. Hausman (2013), Assimilation procedures for updating ionospheric profiles below the F2 peak, Radio Sci., 48(2), 143–157, doi: /rds Elvidge, S., M. J. Angling, B. Nava, On the use of modified Taylor diagrams to compare ionospheric assimilation models, Radio Sci., 49, doi: /2014RS / 24