Validation of the STORM model in IRI2000 at a high latitude station

MANSILLA, G., M. MOSERT

Praga Republica Checa

Workshop; IRI/Cost296 Workshop; 2007

  The latest version of the International Reference Ionosphere IRI contains geomagnetic activity dependence based on an empirical storm time ionospheric correction (STORM model).  An extensive validation of the STORM model for the middle latitude region has been performed. Also, in previous papers it was demonstrated an improvement of IRI with STORM model at low latitudes. In this paper the ability of the STORM model to predict foF2 values at high latitudes is analyzed. For this, ionosonde data obtained at Base Gral. San Martin (68.10S, 2930E) are compared with those obtained by the IRI model with or without storm correction during four geomagnetic storms occurred in 2000 (Rz12= 117) and 2001 (Rz12=111). The results show that predicted values with the STORM model follow the behaviour of foF2 data better than without the STORM model. The relative deviation between measured and predicted foF2 reaches values of up to 24 % and 43 % with and without the STORM model in IRI, during the main phase of the storms. In addition, possible physical mechanisms to explain increases of electron density observed prior to the storm onset and decreases of electron density observed during the first part of the recovery of the storm are discussed.