Solar activity beyond the disk and variations of the cosmic ray gradient

Part of galactic cosmic rays (CR) observed near the Earth and on the Earth come from beyond-disk regions of circumsolar space. But CR of those energies which undergo substantial modulation cover too large a path across the lines of force of the interplanetary magnetic field (IMF) in order that they could provide an effective transfer of information about beyond-disk solar activity. And if it is still possible, the most probable channel for transferring such information must be a neutral layer of heliomagnetosphere in which the transverse CR transport is facilitated by their drift in an inhomogeneous magnetic field. A simple diffusion model for an expected CR variation in a neutral layer near the Earth is discussed. It is of importance that variations of the CR gradient are not at all always accompanied by considerable variations of IMF and solar wind velocity at the point of observation

Unusual decrease of the cosmic ray intensity in May 2019 on the background of the minima solar activity

In May 2019 there was a long and sloping decreasing of cosmic ray’s intensity (up to ~4%), which was observed on neutron monitors. Despite this was a small decreasing compared to quasi-eleven-period variation, it stands out well in 24th cycle of solar activity. According to LASCO/SOHO and STEREO-A data from spectrometer in different UHF bands and from coronograph, there was a series of CMEs which affected on modulation of cosmic rays by creating a series of Forbush decrea - sing, which didn’t restore. This series was connected to two active regions on sun and began on April 30 from “reversed halo” CME. This CME didn’t reach the earth, but led to significant additional modulation of cosmic rays, mostly on east side. Later there was a series of smaller CMEs on May 1-6, which also didn’t reach the earth, but were gradually approaching to Earth. Recent CMEs on 8-9 and 12-13 created a normal Forbush decreasing. In May 2019, cosmic rays shown again, that they can collect information about distant objects of geliosphere and transmit it to Earth. The ground-level detectors sometimes can observe an interaction of interplanetary distur- bances, which didn‘t reach the earth. East CMEs are especially effective, because they closing magnetic field lines beyond the orbit of earth and can interfere the restoring of cosmic ray’s intensity

COSMIC-RAY VARIATIONS DURING THE TWO GREATEST BURSTS OF SOLAR ACTIVITY IN THE 23RD SOLAR CYCLE

Abstract. During two extreme bursts of solar activity in March-April 2001 and October-November 2003, the ground-based neutron monitor network recorded a series of outstanding events distinguished by their magnitude and unusual peculiarities. The important changes that lead to increased activity initiated not with the sunspot appearance, but with the large-scale solar magnetic field reconfiguration. A series of strong and moderate magnetic storms and powerful proton events (including ground-level enhancements, GLE) were registered during these periods. The largest and most productive in the 23rd solar cycle, active region 486, generated a significant series of solar flares among which the 4 November 2003 flare (X28/3B) was the most powerful X-ray solar event ever observed. The fastest arrival of the interplanetary disturbance from the Sun (after August 1972) and the highest solar wind velocity and IMF intensity were recorded during these events. Within 1 week, three GLEs of solar cosmic rays were registered by the neutron monitor network (28 and 29 October and 2 November 2003). In this work, we perform a tentative analysis of a number of the effects seen in cosmic rays during these two periods, using the neutron monitor network and other relevant data

The burst of solar and geomagnetic activity in August–September 2005

During the August–September 2005 burst of solar activity, close to the current solar cycle minimum, a significant number of powerful X-ray flares were recorded, among which was the outstanding X17.0 flare of 7 September 2005. Within a relatively short period (from 22 August to 17 September) two severe magnetic storms were also recorded as well as several Forbush effects. These events are studied in this work, using hourly mean variations of cosmic ray density and anisotropy, derived from data of the neutron monitor network. During these Forbush effects the behavior of high energy cosmic ray characteristics (density and anisotropy) is analyzed together with interplanetary disturbances and their solar sources, and is compared to the variations observed in geomagnetic activity. A big and long lasting (~6 h) cosmic ray pre-decrease (~2%) is defined before the shock arrival on 15 September 2005. The calculated cosmic ray gradients for September 2005 are also discussed

The unusual cosmic ray variations in July 2005 resulted from western and behind the limb solar activity

One of the most interesting and unusual periods of the recent solar activity was July 2005. Despite the fact that it was a late declining phase of the 23rd solar cycle, generally a time of solar quiescence, that period was marked by extreme activity. The main events occurred at the invisible side of the Sun and did not reveal significant consequences in the Earth or near the Earth. However, cosmic ray variations testify to the high power of these events. A rather unusual Forbush effect was observed starting from July 16, 2005. It was characterized by very large cosmic ray anisotropy, the magnitude and direction of which are in accordance with a western powerful source. Usually in such a case when the main interplanetary disturbance is far in the west, the Forbush effect is absent or it is very small and short lasting. In July 2005 a rare exclusion was observed which may testify to the giant decrease of 10 GV cosmic ray density (quite possible >=30%, indicating an unusually high cosmic ray gradient) to the west from the Sun-Earth line. In this work, a description of the July 2005 situation as well as the results of the convection- diffusion treatment with space cosmic ray gradients is presented. Some general remarks concerning extreme western solar events and their impact on cosmic rays are also discussed. © 2008 COSPAR

The burst of solar and geomagnetic activity in August-September 2005

During the August-September 2005 burst of solar activity, close to the current solar cycle minimum, a significant number of powerful X-ray flares were recorded, among which was the outstanding X17.0 flare of 7 September 2005. Within a relatively short period (from 22 August to 17 September) two severe magnetic storms were also recorded as well as several Forbush effects. These events are studied in this work, using hourly mean variations of cosmic ray density and anisotropy, derived from data of the neutron monitor network. During these Forbush effects the behavior of high energy cosmic ray characteristics (density and anisotropy) is analyzed together with interplanetary disturbances and their solar sources, and is compared to the variations observed in geomagnetic activity. A big and long lasting (̃6 h) cosmic ray pre-decrease (̃2%) is defined before the shock arrival on 15 September 2005. The calculated cosmic ray gradients for September 2005 are also discussed. © Author(s) 2009

Anomalous Forbush effects from sources far from Sun center

The Forbush effects associated with far western and eastern powerful sources on the Sun that occurred on the background of unsettled and moderate interplanetary and geomagnetic disturbances have been studied by data from neutron monitor networks and relevant; measurements of the solar wind parameters. These Forbush effects may be referred to a, special sub-class of events, with the characteristics like the event in July 2005, and incorporated by the common conditions: absence of a significant disturbance in the Earth vicinity absence of a strong geomagnetic storm; slow decrease of cosmic ray intensity during the main phase of the Forbush effect. General features and separate properties in behavior of density and anisotropy of 10 GV cosmic rays for this subclass are investigated

Programmed labor in women with a operated uterus

The paper deals with the problems of programmed delivery in women with a uterine scar. The study included 144 pregnant women with a uterus operated who started to give birth vaginally (per vias naturales). The conditions for induction, analyze the clinical efficacy of different methods of induction were assessed. 134 women given birth successfully, programmed delivery were conducted in 84 patients. There were 3 ruptures of the uterus

Cosmic-ray variations during the two greatest bursts of solar activity in the 23rd solar cycle

During two extreme bursts of solar activity in March-April 2001 and October-November 2003, the ground-based neutron monitor network recorded a series of outstanding events distinguished by their magnitude and unusual peculiarities. The important changes that lead to increased activity initiated not with the sunspot appearance, but with the large-scale solar magnetic field reconfiguration. A series of strong and moderate magnetic storms and powerful proton events (including ground-level enhancements, GLE) were registered during these periods. The largest and most productive in the 23rd solar cycle, active region 486, generated a significant series of solar flares among which the 4 November 2003 flare (X28/3B) was the most powerful X-ray solar event ever observed. The fastest arrival of the interplanetary disturbance from the Sun (after August 1972) and the highest solar wind velocity and IMF intensity were recorded during these events. Within 1 week, three GLEs of solar cosmic rays were registered by the neutron monitor network (28 and 29 October and 2 November 2003). In this work, we perform a tentative analysis of a number of the effects seen in cosmic rays during these two periods, using the neutron monitor network and other relevant data. © Springer 2005