N. G. Ptitsyna

Cosmic-ray forecasting features for big forbush decreases

It is well known that big geomagnetic storms have an adverse influence on technological devices and radio wave propagation. Major geomagnetic storms, associated with Forbush decreases (FDs) in cosmic ray (CR) intensity, have also been found to increase the incidence of some diseases (in particular, the frequency of myocardial infarction increases by 13 ± 1.4%). We discuss here three phenomena that can be used for forecasting FDs: 1) CR intensity increase, of non solar-flare origin, occurring before sudden commencement of a major geomagnetic storm connected with FD (preincrease effect), 2) CR intensity decrease before FD (predecrease effect), 3) change in CR fluctuations before FD. First we investigate several such events by the global survey method for the years 1989–1991. We analyse the behaviour of the isotropic CR intensity and of the 3-dimensional vector of CR anisotropy before FDs, as well as results on CR scintillation of 1-hour and 5-minute data. We discuss a possible procedure of data treatment for future FD-forecasting analyses.

The relation of high- and low-orbit satellite anomalies to different geophysical parameters

Satellite anomaly data in the period 1971–1994 were analyzed in the search of possible influence of different space environmental parameters. The database was created by combining, beyond the malfunction information, various characteristics of space weather: geomagnetic activity indices, fluxes and fluences of electrons and protons at different energy, high energy cosmic ray variations, solar wind characteristics and other solar, interplanetary and geophysical data. Satellites were divided on several groups according to the orbital characteristics (altitude and inclination). It was found, that the relation of satellite malfunctions to the environmental parameters is different for various orbits. This fact should be taken into account for the developing of malfunction frequency models.

Effect of Geomagnetic Disturbances on the Operation of Railroad Automated Mechanisms and Telemechanics

Geomagnetic variations generate electric currents in long conductors such as high-voltage lines, pipelines, and telecoms cables. The aim of our work is to study the possible effect of geomagnetic disturbances on the operation of automated systems and telemechanics of a midlatitude railroad based on the data on the malfunctions and breakdowns registered in 2004 on the East Siberian railroad (VSZhD). It has been obtained that the total daily duration of malfunctions and breakdowns (T) during disturbed periods is controlled by geomagnetic activity. When a peak of geomagnetic activity is reached during a storm, T increases about three times. Moreover, a correlation between T and the local index of geomagnetic activity (A), measured at Podkamennaya Tunguska Siberian observatory, is high during disturbed periods. Specifically, the correlation coefficient (K) is equal to 0.83 and 0.71 for the strongest two storms of 2004 that occurred in July 17–August 2 and November 4–18, respectively.

Great geomagnetic storms in 1841–1870 according to the data from the network of Russian geomagnetic observatories

Great magnetic storms (geomagnetic index C9 is ≥8 for St. Petersburg, which can correspond to Kp ≥ 8 or Dst < −200 nT), registered from 1841 to 1870 at the St. Petersburg, Yekaterinburg, Barnaul, Nerchinsk, Sitka, and Beijing (at the Russian embassy) observatories are analyzed. A catalog of intensive magnetic storms during this period, which includes solar cycles 9–11, has been compiled. The statistical characteristics of great magnetic storms during this historical period have been obtained. These results indicate that high solar activity played a decisive role in the generation of very intense magnetic storms during the considered period. These storms are characterized by only one peak in a solar cycle, which was registered in the years of the cycle minimum (or slightly earlier): the number of great geomagnetic storms near the solar activity maximum was twice as large as the number of such storms during less active periods. A maximum in September–October and an additional maximum in February are observed in the annual distribution of storms. In addition, the storm intensity inversely depends on the storm duration.

Health Effects among Engine Drivers: Possible Association with Occupational Exposure to Magnetic Fields from DC Electrified Transport

The initial interest on possible health hazard from exposure to low-frequency, low-intensity magnetic fields (MFs) was mainly concentrated on MFs from power transmission lines (50/60 Hz). Elevated risks of diseases such as leukemia, brain tumor, and male breast cancer have been identified in a variety of professions. Values of risk factors are often 2 or 3 times higher than for residential studies. However, more recently, electrified transportation modes have also come under consideration. A 2-fold increased risk for leukemia mortality has been observed in line and shunting yard drivers of the Swiss Federal Railways with respect to train attendants and station managers.1 An analysis made in Sweden revealed that railway engine drivers and train staff have increased risk in some specific kind of cancer, as leukemia2 and brain tumor,3 though the total cancer incidence (all tumors included) among railway engine drivers was lower than in the general Swedish population. An other study4 on Swedish railway personnel showed that engine drivers had a higher than expected frequency of chromosomal aberrations. A study on workers of Swiss Railways5 showed that exposure to 16.7 Hz MFs may alter the urinary 6-hydroxymelatonin sulfate excretion in humans. There are indications on possible hazards of MFs from electric railways also for people living nearby. For instance in two studies conducted in USA and Germany it was found that sudden infant deaths are clustered near electric railroads.6

Exposure Metrics of Magnetic Fields from Electrified Transport

Biological and epidemiological studies indicate that possible bioeffects of magnetic fields (MFs) could be related to a variety of different exposure metrics.1 For instance, the effects might:

Secular variations in the geomagnetic field in St. Petersburg and the adjacent area from historical data, 1630–1930

Geomagnetic field parameters have been measured in different sites of the northwest of Russia for hundreds of years. This work presents the results of numerous measurements in St. Petersburg, as well as in the Gulf of Finland within the zone from 25° to 30°30′ E and from 59° to 61° N. The first measurements were made in the period1630–1650. For this work, archival data, provided by the Archives of the St. Petersburg Magnetic Observatory (SPbF IZMIRAN), and data from different historical records have been used. Data on the Earth’s magnetic field variations in St. Petersburg have been recorded since 1726; they were analyzed and corrected to get a uniform and complete data set. The reconstructed long-term data set of magnetic variation measurements in St. Petersburg was compared with the GUFM1 historical model. This model allows us to calculate the values of all parameters of the main magnetic field in any place on the Earth since 1590. The comparative analysis carried out by us has revealed a discrepancy between the model and measured values. This discrepancy can be caused by local secular variations in the magnetic field in the St. Petersburg region. The correction of the area-averaged secular variation makes this discrepancy insignificant.

Do Natural Magnetic Fields Disturb Railway Telemetry

Intense geomagnetically induced currents (GIC) can hamper rail traffic by disturbing signaling and train control systems. Objective of this report is to study possible influence of geomagnetic conditions on mid-latitude railway and to perform a statistical study in addition to previous case studies. In this work we analyze 3916 false operations (anomalies) of automatic signaling and train control equipment, occurred in 2004 on the mid-latitude East Siberian Railway (latitudes: 51-56 N; longitudes: 96-114 E). Our results revealed links between geomagnetic disturbances and anomalies in the operation of railway automatics and telemetry.

Magnetic Field Monitoring on Board of DC Electrified Transport in Russia

During the last few decades the intensity level of electromagnetic field (EMF) environment has dramatically increased: devices generating EMFs have proliferated in industrial plants, public transportation systems, homes, etc. This new situation is often described as “EM pollution” or “EM smog”. One of the main components of EM pollution is the magnetic field (MF) produced by electrified transport.

Long-Term Trends and Seasonal Variations in Geomagnetic Storms from Data of St. Petersburg Observatories (1878–1954)

The annual number of magnetic storms N recorded at St. Petersburg observatories (Pavlovsk/Slutsk and Voyeykovo) in 1878–1954 is studied. The analysis shows that N has increased since ~1900 for different storm types (storms with sudden commencement Ssc and storms with gradual Sg commencement; moderate, strong and very strong); however, the number of Ssc storms increased more rapidly than the number of Sg storms. The percentage of Ssc storms doubled for the first half of the 20th century, while the number of Sg storms decreased by 1.5 times. The Ssc storms are driven by coronal mass ejections from closed magnetic structures on the Sun, and Sg storms are driven by corotating fluxes from open magnetic structures and coronal holes. These results are apparently evidence of an increase in the activity of both types of solar magnetic structures in the first half of the 20th century and a more rapid increase in the activity of fields with closed lines of forces. A semiannual variation with maxima in the periods of vernal and autumnal equinoxes is clearly pronounced for Sg and moderate storms. The tendency to have two equinoctial maxima is pronounced in the total number of storms N for both even and odd cycles; however, maxima that differ from the arithmetic mean by more than a standard deviation are observed only in September in even cycles and in March in odd cycles.