Solar flare detection system based on global positioning system data: First results

Abstract

A solar flare detector has been developed using the Global Positioning System (GPS) capabilities to monitor the ionospheric Total Electron Content (TEC). It is based on obtaining the variation of the vertical TEC data with respect to the previous sidereal day and then, on performing a second order time difference to obtain the information of the instantaneous TEC changes. The detector can be applied looking for solar flares backwards or in real time as well. To make a first assessment of the solar flare detector, several specific days, when there is the certainty that a solar flare had occurred, have been analyzed. The results, which are presented in this work, have been obtained from the X17.2 flare on 28th October, 2003, the X5.7 flare on 14th July, 2000 and the X7.1 flare on 20th January, 2005, using the GPS data of the International GNSS Service (IGS) network with a sampling rate of 30 s. The results obtained are compatible with the results presented previously by different authors, and with the flare records included in the Geostationary Operational Environmental Satellite (GOES) database. In addition, several receivers, located in the southern hemisphere and far from the geomagnetic equator, detect a lower overionization amplitude than other receivers with similar mean solar zenith angle. Moreover, minor disturbances in the TEC enhancement can also be observable and studied.

Global prediction of the vertical total electron content of the ionosphere based on GPS data

“…In this regard, tests feeding the UPC prediction model with physical information including indexes of solar/geomagnetic activity, such as Kp and Solar Flux, are currently being conducted. Also in this context, a detector of solar flares facing the earth that may be used to input additional physical information into the prediction model has been developed by the authors [see García‐Rigo et al , 2008, 2006]. Apart from that, further improvement could be obtained by using a geomagnetic grid rather than a geographic one or by using a subset of the regression coefficients (for instance, they could be determined by feature selection [ Hastie et al , 2001]).…”

Testing regional vertical total electron content maps over Europe during the 17–21 January 2005 sudden space weather event

“…The whole week from 16 January 2005 was dominated by one single big sunspot group, which was clearly visible on the solar disk (http://sidc.oma.be) [see, e.g., Garcia‐Rigo et al , 2007]. The group produced an M‐ and X‐flaring period with a wide impact on both solar‐terrestrial physical system and technology.…”

Solar flare effect on the geomagnetic field and ionosphere

“…The observation of permanent GPS tracking stations, under the management of the International GPS Service (IGS), has become a powerful tool for ionospheric research, providing good, continuous worldwide coverage at low cost to the users. Many authors have used GPS for total electron content (TEC) observations and in the study of ionospheric space weather (Aarons et al, 1997;Ho et al, 1998;Jakowski et al, 1999;Afraimovich et al, 2000;Meza et al, 2005), especially for SITEC properties (Afraimovich, 2001(Afraimovich, , 2002(Afraimovich, , 2000Zhang et al, 2002;Xiao, 2003, 2005;Liu et al, 2004Liu et al, , 2006Wan et al, 2005;García Rigo et al, 2007). In particular, Zhang et al (2002) analysed the ionospheric response to a solar flare similar to the flare used in this work; they found that the enhancement of TEC tended to depend on latitude, longitude, and the solar zenith angle of the subionospheric point, but not symmetrically, and it was smaller in the local morning than in the afternoon.…”