Assimilating diverse kinds of data into NeQuick 2

NAVA BRUNO; AZPILICUETA FRANCISCO; KASHCHEYEV ANTON

Montreal

Simposio; XXXII URSI General Assembly & Scientific Symposium; 2017

URSI

NeQuick 2 is the ionosphere electron density model developed at the Abdus Salam International Centre for Theoretical Physics (ICTP) ‐ Trieste, Italy in collaboration with the University of Graz, Austria. It is an empirical model conceived to reproduce the median behavior of the ionosphere.In order to retrieve the 3-D description of the ionosphere electron density for current conditions, different data ingestion techniques have been implemented. They are based on the NeQuick adaptation to ground and space-based GNSS-derived (Total Electron Content) TEC data and ionosonde measured peak parameter values [2,3].Recently, the NeQuick has also been used to provide a priori information in sophisticated assimilation schemes,which are able to incorporate direct and indirect measurementsof the ionosphere electron density [4].Theseabove mentioned techniques have demonstrated their effectiveness to improve the model capabilityto retrieve the ionosphere electron density at a given location and time. They have also indicated possible ways of improvements (e.g. slab thickness formulation), underlining the importance of ingesting the F2 layer peak parameters, as mentionedby Minkwitz.A technique based on the Best Linear Unbiased Estimator (BLUE) has therefore been implemented to assimilate ground-based and space-based (Radio Occultation-derived) TEC data into NeQuick 2 in order to obtain 3-D specification of the ionosphere electron density in the area of interest. In particular, the observation and background error covariance matrices have been implemented following Yue et al., with a simplification in terms of the correlation distance formulation. At first, only regional and instantaneous 3-D electron density reconstructions have been performed on the basis of the available data, and no time propagation of the solution has been tried.In the present work, the capability of the proposed assimilation technique to reconstruct the ionosphere electron density isdiscussed.Particular attention is devoted to the role of NeQuick as a background model: used in a standard way (withthe daily solar flux as an input), orafter a preliminary adaptation to F2 layer peak parameter values.