Comparative analysis of NOAA REFM and SNB3GEO tools for the forecast of the fluxes of high-energy electrons at GEO.

M A Balikhin,S A Billings,H Aryan,J V Rodriguez,R J Boynton,D G Sibeck,S N Walker

doi:10.1002/2015sw001303

Abstract

Reliable forecasts of relativistic electrons at geostationary orbit (GEO) are important for the mitigation of their hazardous effects on spacecraft at GEO. For a number of years the Space Weather Prediction Center at NOAA has provided advanced online forecasts of the fluence of electrons with energy >2 MeV at GEO using the Relativistic Electron Forecast Model (REFM). The REFM forecasts are based on real‐time solar wind speed observations at L1. The high reliability of this forecasting tool serves as a benchmark for the assessment of other forecasting tools. Since 2012 the Sheffield SNB3GEO model has been operating online, providing a 24 h ahead forecast of the same fluxes. In addition to solar wind speed, the SNB3GEO forecasts use solar wind density and interplanetary magnetic field B z observations at L1.The period of joint operation of both of these forecasts has been used to compare their accuracy. Daily averaged measurements of electron fluxes by GOES 13 have been used to estimate the prediction efficiency of both forecasting tools. To assess the reliability of both models to forecast infrequent events of very high fluxes, the Heidke skill score was employed. The results obtained indicate that SNB3GEO provides a more accurate 1 day ahead forecast when compared to REFM. It is shown that the correction methodology utilized by REFM potentially can improve the SNB3GEO forecast.

Highlights

The smooth operation of modern society depends upon the ability for the fast exchange of information between various organizations and individuals
The scatter plots for the two models are similar (Figure 1), with the somewhat greater scatter in the Relativistic Electron Forecast Model (REFM) results leading to slightly larger correlation values for SNB3GEO
The value of the prediction efficiency (PE = 0.8187) is similar but seems slightly higher than the mean of the values from Figure 2 of Perry et al [2010] obtained for three forecast models that were investigated by Perry et al [2010]

Summary

Introduction

The smooth operation of modern society depends upon the ability for the fast exchange of information between various organizations and individuals. Spacecraft operating at geostationary orbit (GEO) form an essential part of our modern technological infrastructure that enables this information exchange. In spite of the provision of some shielding on board the spacecraft, energetic electrons are still able to penetrate deep inside the spacecraft subsystems and components, potentially resulting in internally induced electrostatic discharges. Induced electrostatic discharges can cause anomalies in spacecraft operation and even the failure of vulnerable subsystems [Vampola, 1987; Baker et al, 1987; Wrenn, 1995; Fennell et al, 2000; Bodeau, 2010]. The reliable forecast of high-energy electron fluxes at GEO can assist in the mitigation of hazardous space weather effects on spacecraft operations there

Results

Discussion

Conclusion