We present new observational data on the phenomena of extremely high activity on the Sun and in the heliosphere that took place in October-November 2003. A large variety of solar and heliospheric parameters give evidence that the interval under consideration is unique over the entire observation time. Based on these data, comparing them with similar situations in the past and using available theoretical concepts, we discuss possible cause-and-effect connections between the processes observed. The paper includes the first results and conclusions derived by the collaboration "Solar Extreme Events-2003" organized in Russia for detailed inves- tigations of these events. As a result of our consideration, it is beyond question that the physical causes of solar and heliospheric phenomena in October-November 2003 are not exclusively local and do not belong only to the active regions and solar atmosphere above them. The energy reservoirs and driving forces of these processes have a more global nature. In general, they are hidden from an observer, since ultimately their sources lie in the subphotospheric layers of the Sun, where changes that are fast and difficult to predict can sometimes take place (and indeed they do). Solar flares can serve as sufficiently good tracers of these sudden changes and reconstruc- tions on the Sun, although one can still find other diagnostic indicators among the parameters of magnetic fields, motions of matter, and emission characteristics.

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Solar and Heliospheric Phenomena in October-November 2003: Causes and Effects

[1] A study was undertaken to estimate the radial diffusion timescale, τLL, for relativistic electrons (2–6 MeV) to diffuse into the slot region due to drift-resonance with Pc5 ULF waves (2–10 mHz) on 29 October 2003. Large amplitude ULF waves were observed by ground-based magnetometer arrays to penetrate deep into the slot region (L ≃ 2–3) starting at 0600 UT and maximising (∼200 nT p-p) between 0930–1630 UT. Around the same time, the SAMPEX PET instrument measured an over two orders of magnitude increase in relativistic (2–6 MeV) electron flux levels in ∼24 hours within the slot region. The ground-based D-component magnetic power spectral densities (PSDδB) for 29 October were estimated for six latitudinally spaced ground stations covering L ∼ 2.3–4.3 for an observed ULF wave with central frequency ∼4 mHz. The PSDδB values were used to calculate the in situ equatorial poloidal wave electric field power spectral densities (PSDδEm) using a standing Alfven wave model. The radial diffusion coefficients, DLL, were estimated using the PSDδEm values. The fastest τLL were 3–5 hours at L > 4, while τLL initially increased with decreasing L-value below L ≃ 4; peaking at L ≃ 3 with τLL ∼ 12–24 hours with PSDδEm estimated using a wave frequency bandwidth between Δf = 1 mHz and Δf = 2.5 mHz. The τLL over the L-range L ∼ 2.3–3.3 were consistent with the timescales observed by SAMPEX for the increase in relativistic fluxes in the slot region on 29 October. The authors believe that this is the first example of the ULF wave drift-resonance with relativistic electrons explaining a radiation belt slot region filling event.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2005JA011355

Radial diffusion of relativistic electrons into the radiation belt slot region during the 2003 Halloween geomagnetic storms

Observations of Antarctic precipitable water vapor and its response to the solar activity based on GPS sensing

A year after the extreme events on the Sun, in the heliosphere, and on the Earth in October–November 2003 [Veselovsky et al. , 2004; Panasyuk et al. , 2004; Yermolaev et al. , 2005], a similar situation was also observed in November 2004. The main data observed when the strongest magnetic storm with Dst = –373 nT occurred on the Earth are presented in the paper prepared mainly by the participants of the last year’s collaboration of native researchers of extreme events. The disturbance of the Sun, solar wind, and magnetosphere during the considered period was weaker than during the similar period in 2003 with respect to a number of parameters; nevertheless, the presented data indicate that the decline phase of solar cycle 23 is one of the most active intervals over the entire period of comprehensive studies of the solar–terrestrial coupling owing to the events that occurred in autumn 2003 and 2004.

/pdf/a-year-later-solar-heliospheric-and-magnetospheric-303171ozar.pdf

A year later: Solar, heliospheric, and magnetospheric disturbances in November 2004

The first results obtained through the university small satellites program developed at Moscow State University (MSU) are presented. The space environment was investigated aboard two MSU microsatellites designed for scientific and educational purposes, Universitetsky-Tat’yana and Universitetsky-Tat’yana-2. The scientific equipment is described to study charged particles in near Earth space and atmospheric radiations in ultraviolet, red, and infrared optical wavelength ranges. The dynamic properties of fluxes of charged particles in microsatellite orbits are studied and findings are presented regarding specific parameters of solar proton penetration during the geomagnetic disturbances. Experimental results are considered concerning flashes of ultraviolet (UV), red (R), and infrared (IR) radiation that are transient light phenomena in the upper atmosphere. The space educational MSU program developed on the basis of the Universitetsky-Tat’yana projects is reviewed.

Investigations of the space environment aboard the Universitetsky-Tat’yana and Universitetsky-Tat’yana-2 microsatellites

Preliminary results of an analysis of satellite and ground-based measurements during extremely strong magnetic storms at the end of October 2003 are presented, including some numerical modeling. The geosynchronous satellites Ekspress-A2and Ekspress-A3, and the low-altitude polar satellites Coronas-F and Meteor-3M carried out measurements of charged particles (electrons, protons, and ions) of solar and magnetospheric origin in a wide energy range. Disturbances of the geomagnetic field caused by extremely high activity on the Sun were studied at more than twenty magnetic stations from Lovozero (Murmansk region) to Tixie (Sakha-Yakutia). Unique data on the dynamics of the ionosphere, riometric absorption, geomagnetic pulsations, and aurora observations at mid-latitudes are obtained.

S.I. Soloviev

Papers

Magnetic storms in October 2003