1. 1 SPbIZMIRAN, Russia University “Roma Tre”, Italy Institute of Irkutsk Railroad Engineering, Russia Israel CR Center, Tel-Aviv University, Israel N.G. Ptitsyna, G. Villoresi M.I. Tyasto, V. V. Kassinsky SPACE WEATHER AND RAILROADS: INCREASE OF TELEMETRY FAILURES DURING GEOMAGNETIC STORMS IN 2004-2005

2. 2 INTRODUCTION Geomagnetic variations generate secondary electric currents in conductive layers of the Earth's lithosphere (telluric currents) and in artificial long conductors as power lines, pipelines and railway systems. Intense geomagnetically induced currents GIC can hamper rail traffic by disturbing operation of automatic mechanisms and telemetry as signaling and train control devices. We analyzed the statistical data on failures in the operation of these systems registered in 2004-2005 on the Russian mid latitude East Siberian Railway in order to search for possible relations to geomagnetic activity.

3. 3 GIC effects in railways Intense geomagnetically induced currents (GIC) can hamper rail traffic by disturbing railway automatics and telemetry -- signaling and train control systems Intense geomagnetically induced currents (GIC) can hamper rail traffic by disturbing railway automatics and telemetry -- signaling and train control systems High-latitudes → disturbances driven by electrojet intensifications High-latitudes → disturbances driven by electrojet intensifications Mid-latitudes → other geomagnetic storm processes (SSC, geomagnetic pulsations) Mid-latitudes → other geomagnetic storm processes (SSC, geomagnetic pulsations)

4. 4 Effects of geomagnetic storm of 13-15 May, 1921: mid-latitude “railroad storm” New York Times, May 16, 1921:“The prelude to this particular storm began with a major sunspot sighted on the limb of the sun vast enough to be seen with the naked eye through smoked glass. The spot was 94,000 miles long and 21,000 miles wide and by May 14th was near the center of the sun in prime location to unleash an earth- directed flare. The 3-degree magnetic bearing change among the five worst events recorded ended all communications traffic from the Atlantic Coast to the Mississippi. At 7:04 AM on May 15, the entire signal and switching system of the New York Central Railroad below 125th street was put out of operation, followed by a fire in the control tower at 57th Street and Park Avenue. The cause of the outage was later ascribed to a 'ground current' that had invaded the electrical system. Railroad officials formally assigned blame for a fire destroyed the Central New England Railroad station, to the aurora. Over seas, in Sweden a telephone station was 'burned out', and the storm interfered with telephone, telegraph and cable traffic over most of Europe”.

5. 5 OBJECTIVES To study possible influence of geomagnetic conditions on mid-latitude railway To study possible influence of geomagnetic conditions on mid-latitude railway For this we analyze failures of automatic signaling and train control equipment occurred in 2004-2005 on the mid-latitude East Siberian Railway To compare results for 2005 and 2004 data To compare results for 2005 and 2004 data

6. 6 East Siberian Railway (green and red lines) Geomag. latitude 46°N-51°N; Geomag. longitude 168°E-187°E

7. 7 DATA Failures in operation of signaling and train control equipment were registered daily in 2004-2005. The failures consist mainly in unstable functioning and misopeartions in automatic block-system (track circuit, switches, locomotive control devices) often resulting in false engagement of railway tracks and in red signals instead of green ones. About 45% of failures were due to meteorologically connected reasons (snow, ice or sand in automatic switches), wire breakage, staff errors and vandalism. We did not take them into account analysing possible links with geomagnetic parameters.

8. 8 Severity of failures in relation to development of geomagnetic storms In automatic block-systems the lock-out feature (e.g., a locking- out relay) shuts down and holds the equipment out of service until the abnormal condition ends. Thus, we took failure duration T as a parameter characterizing the severity of the failure. We used: local A index Intense geomagnetic storms (Amax>30) T - the daily sum of duration (in min) of failures observed in all railway divisions – was calculated for ~20-day intervals around storms Correlation between the moving 5-day average for and

9. 9 Examples of Correlation of Failure Durations T and Geomagnetic Index A for storms in 2004 Daily sum of failure duration T during evolution of geomagnetic storms. Blue – (min/10); Pink - local geomagnetic index (nT). Severity of failures (characterized by failure duration T) is geomagnetically dependent. An increase of T (by a factor of  3) during geomagnetic storms is observed. A high degree of correlation between T and A in 2004.

10. 10 Examples of Correlation of Failure Duration T and Geomagnetic Index A for storms in 2005 Blue – duration of failures in operation of signaling and train control equipment (in min/10), Pink - local geomagnetic index ;, - moving 5-day averages.  An increase of T during geomagnetic storms  An increase of T by a factor of 3-5 during geomagnetic storms  A high correlation between and  A high correlation between and

11. 11 Daily sum of failure duration T during evolution of geomagnetic storms Daily sum of failure duration T during evolution of geomagnetic storms (2005, another example) Blue – (min/10); Pink - local geomagnetic index (nT). An increase of T during geomagnetic storms An increase of T by a factor of  3 during geomagnetic storms A high degree of correlation between and is found for 2005 as well as for 2004 A high degree of correlation between and is found for 2005 as well as for 2004 It has also been found a significant correlation between the T and different indices of geomagnetic activity (Ap, Kp, Dst and local index A in the Siberian magnetic observatory Podkamennaya Tunguska) during disturbed periods.

12. 12 RESULTS  We have presented evidences for links between geomagnetic disturbances and failures in the operation of mid-latitude railway automatics and telemetry.  We found -An increase of the daily duration of failures in operation of automatic signaling and train control equipment occurred on the East Siberian Railway in 2005 by a factor of 2-5 during geomagnetic storms. -A significant correlation between the daily sum of failure durations T and local geomagnetic index A.  These results consistent with results obtained for anomalies observed in 2004 year.