C. Sarlanis - Academia.edu (original) (raw)

Uploads

Papers by C. Sarlanis

Research paper thumbnail of Optimizing the real-time ground level enhancement alert system based on neutron monitor measurements: Introducing GLE Alert Plus

Space Weather, 2014

ABSTRACT Whenever a significant intensity increase is being recorded by at least three neutron mo... more ABSTRACT Whenever a significant intensity increase is being recorded by at least three neutron monitor stations in real-time mode, a ground level enhancement (GLE) event is marked and an automated alert is issued. Although, the physical concept of the algorithm is solid and has efficiently worked in a number of cases, the availability of real-time data is still an open issue and makes timely GLE alerts quite challenging. In this work we present the optimization of the GLE alert that has been set into operation since 2006 at the Athens Neutron Monitor Station. This upgrade has led to GLE Alert Plus, which is currently based upon the Neutron Monitor Database (NMDB). We have determined the critical values per station allowing us to issue reliable GLE alerts close to the initiation of the event while at the same time we keep the false alert rate at low levels. Furthermore, we have managed to treat the problem of data availability, introducing the Go-Back-N algorithm. A total of 13 GLE events have been marked from January 2000 to December 2012. GLE Alert Plus issued an alert for 12 events. These alert times are compared to the alert times of GOES SWPC and UMASEP. In all cases GLE Alert Plus precedes the GOES alert by ≈ 8-52 min. The comparison with UMASEP demonstrated a remarkably good agreement. Real-time GLE alerts by GLE Alert Plus may be retrieved by http://cosray.phys.uoa.gr/gle_alert_plus.html;http://www.nmdb.eu and http://swe.ssa.esa.int/web/guest/space-radiation. An automated GLE alert email notification system is also available to interested users.

Research paper thumbnail of Space Storm Measurements of 17 and 21 April 2002 Forbush Effects from Artemis-IV Solar Radio-Spectrograph, Athens Neutron Monitor Station and Coronas-F Satellite

Research paper thumbnail of Athens Neutron Monitor and its aspects in the cosmic-ray variations studies

After many years break (since the 1978) the Athens Neutron Monitor renewed its operation due to j... more After many years break (since the 1978) the Athens Neutron Monitor renewed its operation due to joint efforts of Athens University (Greece) and IZMIRAN (Russia). In the present work the short history of this station and the modernization of the neutron monitor registration system, which made possible the real time presentation of current measurements in the Worldwide Network are described. The main properties and some advantages of this station in comparison with others are considered in the aspect of using its data for the Solar-Terrestrial and Space Weather studies.

Research paper thumbnail of Primary Data Processing Algorithms for Neutron Monitors

Journal of Physics: Conference Series, 2013

Research paper thumbnail of ALERT SYSTEM FOR GROUND LEVEL COSMIC-RAY ENHANCEMENTS PREDICTION AT THE ATHENS NEUTRON MONITOR NETWORK IN REAL-TIME

International Journal of Modern Physics A, 2005

Research paper thumbnail of Monitoring and Forecasting of Great Solar Proton Events Using the Neutron Monitor Network in Real Time

IEEE Transactions on Plasma Science, 2004

Research paper thumbnail of Space weather prediction by cosmic rays

Advances in Space Research, 2006

Research paper thumbnail of Athens Neutron Monitor Data Processing Center – ANMODAP Center

Advances in Space Research, 2009

Research paper thumbnail of Joint observations of solar radio bursts and cosmic ray events recorded by the ARTEMIS IV radio spectrograph and Athens Cosmic Ray Station (Super 6NM-64) of the University of Athens

Research paper thumbnail of Optimizing the real-time ground level enhancement alert system based on neutron monitor measurements: Introducing GLE Alert Plus

Space Weather, 2014

ABSTRACT Whenever a significant intensity increase is being recorded by at least three neutron mo... more ABSTRACT Whenever a significant intensity increase is being recorded by at least three neutron monitor stations in real-time mode, a ground level enhancement (GLE) event is marked and an automated alert is issued. Although, the physical concept of the algorithm is solid and has efficiently worked in a number of cases, the availability of real-time data is still an open issue and makes timely GLE alerts quite challenging. In this work we present the optimization of the GLE alert that has been set into operation since 2006 at the Athens Neutron Monitor Station. This upgrade has led to GLE Alert Plus, which is currently based upon the Neutron Monitor Database (NMDB). We have determined the critical values per station allowing us to issue reliable GLE alerts close to the initiation of the event while at the same time we keep the false alert rate at low levels. Furthermore, we have managed to treat the problem of data availability, introducing the Go-Back-N algorithm. A total of 13 GLE events have been marked from January 2000 to December 2012. GLE Alert Plus issued an alert for 12 events. These alert times are compared to the alert times of GOES SWPC and UMASEP. In all cases GLE Alert Plus precedes the GOES alert by ≈ 8-52 min. The comparison with UMASEP demonstrated a remarkably good agreement. Real-time GLE alerts by GLE Alert Plus may be retrieved by http://cosray.phys.uoa.gr/gle_alert_plus.html;http://www.nmdb.eu and http://swe.ssa.esa.int/web/guest/space-radiation. An automated GLE alert email notification system is also available to interested users.

Research paper thumbnail of Space Storm Measurements of 17 and 21 April 2002 Forbush Effects from Artemis-IV Solar Radio-Spectrograph, Athens Neutron Monitor Station and Coronas-F Satellite

Research paper thumbnail of Athens Neutron Monitor and its aspects in the cosmic-ray variations studies

After many years break (since the 1978) the Athens Neutron Monitor renewed its operation due to j... more After many years break (since the 1978) the Athens Neutron Monitor renewed its operation due to joint efforts of Athens University (Greece) and IZMIRAN (Russia). In the present work the short history of this station and the modernization of the neutron monitor registration system, which made possible the real time presentation of current measurements in the Worldwide Network are described. The main properties and some advantages of this station in comparison with others are considered in the aspect of using its data for the Solar-Terrestrial and Space Weather studies.

Research paper thumbnail of Primary Data Processing Algorithms for Neutron Monitors

Journal of Physics: Conference Series, 2013

Research paper thumbnail of ALERT SYSTEM FOR GROUND LEVEL COSMIC-RAY ENHANCEMENTS PREDICTION AT THE ATHENS NEUTRON MONITOR NETWORK IN REAL-TIME

International Journal of Modern Physics A, 2005

Research paper thumbnail of Monitoring and Forecasting of Great Solar Proton Events Using the Neutron Monitor Network in Real Time

IEEE Transactions on Plasma Science, 2004

Research paper thumbnail of Space weather prediction by cosmic rays

Advances in Space Research, 2006

Research paper thumbnail of Athens Neutron Monitor Data Processing Center – ANMODAP Center

Advances in Space Research, 2009

Research paper thumbnail of Joint observations of solar radio bursts and cosmic ray events recorded by the ARTEMIS IV radio spectrograph and Athens Cosmic Ray Station (Super 6NM-64) of the University of Athens

Log In