Quasi Periodic Oscillations in the Pre Phases of Recurrent Jets Highlighting Plasmoids in Current Sheet

<p><strong>Solar jets observed at the limb are important to determine the location of reconnection sites in the corona. In this study, we investigate six recurrent hot and cool jets occurring in the active region NOAA 12644 as it is crossing the west limb on April 04, 2017. These jets are observed in all the UV/EUV filters of SDO/AIA and in cooler temperature formation lines in IRIS slit jaw images. The jets are initiated at the top of a double chamber vault with cool loops on one side and hot loops on the other side. The existence of such double chamber vaults suggests the presence of emerging flux with cool loops, the hot loops being the reconnected loops similarly as in the models of Moreno-</strong><strong>Insertis</strong><strong>et al. 2008, 2013 and Nóbrega-Siverio et al. 2016. In the preliminary phase of the main jets, </strong><strong>quasi periodic</strong><strong> intensity oscillations accompanied by smaller jets are detected in the bright current sheet between the vault and the preexisting magnetic field. Individual kernels and plasmoids are ejected in open field lines </strong><strong>along</strong><strong> the jets. Plasmoids may launch torsional Alfven waves and the kernels would be the result of the </strong><strong>untwist</strong><strong> of the plasmoids in open magnetic field as proposed in the model of Wyper et al. 2016.</strong></p>

GEOLOGICAL CONDITIONS OF AURIGEROUS MINERALIZATION LOCALIZATION AND THE STRUCTURE OF MUSHTINSKOE ORE FIELD (KABARDINO-BALKAR REPUBLIC)

По результатам крупномасштабной геологической съемки, геохимических и геофизических данных проведен анализ литолого-структурных условий локализации золотоносных залежей и зон Муштинского рудного поля. Установлено, что важнейшим элементом структуры рудного поля является впервые выяв- ленная нами крупная флексура, осложняющая моноклинально залегающее северо-западное крыло Муш- тинской антиклинали. Обнаруженные в ходе поисковых работ золотоносносные рудные зоны и залежи приурочены к коленам флексуры и ее смыкающему крылу. По комплексу выявленных признаков Муш- тинское рудное поле отнесено к группе рудных полей, приуроченных к складкам с пологим шарниром, осложненным разрывами. Основными факторами отнесения изученного рудного поля к определенному структурному типу в пределах этой группы является многоярусная локализация пологих рудных тел в зам- ках пликативных структур третьего порядка, в сочетании с крутыми рудными телами в осложняющих их разрывных нарушениях. Решающим, при этом, является то, что рудовмещающая флексура проявляется как пликативная деформация только в пластичной малкинской свите, а в подстилающей более метамор- физованной бечасынской свите ее ограничения проявлены дизьюнктивными деформациями. Это позво- ляет считать ее глыбовой структурой. Поэтому Муштинское рудное поле можно отнести к структурному типу, обозначаемому как пластообразные, жильные и сложной формы рудные тела преимущественно в замках и частично на крыльях глыбовых антиклиналей с типичной вертикальной морфологической зо- нальностью The analysis of lithologic-structural conditions of aurigerous deposits and zones localization of Mushtinskoe ore field was carried out based on the results of large-scale geological surveying, geochemical and geophysical data. It was determined that the most important element of the ore field structure is a large flexure found out for the first time by us, which complexifies north-west limb of Mushtinskaya anticline which has a monoclinal folding. Aurigerous ore zones and deposits discovered during prospecting work are confined to the flexure knee and its joint limb. Mushtinskoe ore field is referred to the ore fields group confined to folds with flat apex which is complexified by fractures. The main factors which allow referring studied ore field to the definite structure type within the given group are multilayer localization of flat ore bodies in joists of the third order plicative structures coupled with steep ore bodies in complexified or disruptive faulting. Herewith the determinant factor is that ore hosting flexure appears as plicative deformation only in plastic malkinskaya assise and in underlying more metamorphized bechasynskaya assise its restrictions are shown by disjunctive deformations. This fact allows considering the flexure as a block structure. Thats why Mushtinskoe ore field can be referred to the structural type, defined as sheetlike, veined and complex form ore bodies mainly in joists and partly on the limbs of block anticlines with typical vertical morphologic zonality

Observations of a geomagnetic SI+ – SI− pair and associated solar wind fluctuations

We report a pair of oppositely directed sudden impulses (SI), in the geomagnetic field (ΔX), at ground stations, called SI+ – SI− pairs, that occurred between 1835 UT and 2300 UT on 23 April 1998. The SI+ – SI− pair, was well correlated with corresponding variations in the solar wind density, while solar wind velocity and the southward component of the interplanetary magnetic field (Bz) did not show any correspondence. This event had no source on the visible solar disk but was associated with a rear-side fast partial halo coronal mass ejection (CME) and an optically occulted M1.4 class solar flare behind the west limb. This event was unique in that one could clearly identify variations in ΔX at ground stations with solar wind parameters.

Multispacecraft observations of a prominence eruption

On 9 May 2007 a prominence eruption occurred at the West limb. Remarkably, the event was observed by the STEREO/EUVI telescopes and by the HINODE/EIS and SOHO/UVCS spectrometers. We present results from all these instruments. High-cadence (~37 s) data from STEREO/EUVI A and B in the He II λ304 line were used to study the 3-D shape and expansion of the prominence. The high spatial resolution EUVI images (~1.5"/pixel) have been used to infer via triangulation the 3-D shape and orientation of the prominence 12 min after the eruption onset. At this time the prominence has mainly the shape of a "hook" highly inclined southward, has an average thickness of 0.068 R⊙, a length of 0.43 R⊙ and lies, in first approximation, on a plane. Hence, the prominence is mainly a 2-D structure and there is no evidence for a twisted flux rope configuration. HINODE/EIS was scanning with the 2" slit the region where the filament erupted. The EIS spectra show during the eruption remarkable non-thermal broadening (up to ~100 km s−1) in the region crossed by the filament in spectral lines emitted at different temperatures, possibly with differences among lines from higher Fe ionization stages. The CME was also observed by the SOHO/UVCS instrument: the spectrograph slit was centered at 1.7 R⊙, at a latitude of 5° SW and recorded a sudden increase in the O VI λλ1032–1037 and Si XII λ520 spectral line intensities, representative of the CME front transit.

Microwave observations with the RATAN-600 radio telescope: detection of the thermal emission sources

We report on two off-limb radio sources of microwave emission which were detected in one-dimensional RATAN-600 solar scans of the post-eruptive loops: on December 2, 2003 (off west limb) and January 25, 2007 (east limb). The microwave spectra showed that the thermal emission was predominant at the early stage of the arcade formation with a small contribution of non-thermal emission. There were no high-energy particles in these events. The microwave spectra of the radio sources associated with the tops of postflare loops show the predominant thermal emission during one hour after the eruption. In case of a small contribution from accelerated particles to the microwave emission, there is a large amount of hot plasma in the region of the loop tops after the eruption.

Tectonic implications of 40Ar/39Ar muscovite dates from the Mt. Haley stock and Lussier River stock, near Fort Steele, British Columbia

The Mt. Haley and Lussier River stocks are located northeast of Cranbrook, B.C. near the south end of the Western Main Ranges of the Southern Canadian Rocky Mountains. Both are multiphase, potassium-feldspar porphyritic monzonite plutons that intrude lower Paleozoic miogeoclinal strata. They crosscut and thermally overprint the Lussier River fault and the thrust and fold structures in the east flank of the Purcell anticlinorium and the west limb of the Porcupine Creek anticlinorial fan structure. Muscovite from the Mt. Haley stock yielded a 40Ar/39Ar plateau age of 108.2 ± 0.7 Ma (2σ), and a single-crystal, step-heating analysis of muscovite from a skarn in the metamorphic aureole adjacent to the Lussier River stock gave a plateau date of 108.7 ± 0.6 Ma (2σ). These dates constrain the timing of thrusting and folding in this portion of the western Rocky Mountains and of the displacement along the Lussier River – St. Mary fault to pre-middle Albian.

RATAN-600 Observations of Unusual Inversion of Polarization in Sunspot Associated Microwave Sources

We have discovered unusual inversion of circular polarization in both components of an active region. We have observed the region for six consecutive days in May 96 using the RATAN-600 radio telescope with high polarization accuracy up to 0.5 %. The observations were taken in the range of 1.7 to 30 cm. At short wavelengths the circular polarization scans revealed a bipolar structure, expected since the magnetic field is bipolar. However, for all six days and while the region was moving from the center of the disk to the west limb, the circular polarization dropped practically to zero at 14.5 cm and at longer wavelengths the sense of the polarization was reversed.

Spectroscopic Features in the EUV Emission of a M8 Flare Observed by SUMER

A flare of size M8 occurred while SUMER was recording a spectral scan above the active region NOAA 8537 at the west limb. We recorded spectra during the pre-flare phase, at flare onset, and during the decay phase of this main flare in a series of events. More than 60 flare lines were identified during this observation, which include Fe XVIII - Fe XXIII lines that provide evidence of 107 K plasmas. We also recorded lines from He-like ions, such as Ne IX, Na x, Mg XI, and Si XIII. Accurate wavelength measurements of such lines are of interest in basic atomic physics studies. Using plasma diagnostic techniques, we investigated the temporal evolution of the electron densities and temperatures during the event.

Flare and CME Onset: UV Spectra Show Fast 3-D Flow

We present observations taken in the corona above a flare that occurred on the west limb of the Sun. SUMER spectra show large red (350 km s−1) and blue (650 km s−1) Dopplershifts in Fe XX (107 K), Cr XVI (5 × 106 K), Si IX (106 K) and O III (105 K) emission lines. These shifts are associated with a fast moving (400 km s−1) optical emission front detected in high cadence images, taken with the coronagraph MICA. SXT images show fast soft X-ray ejecta that can be extrapolated back to the position of pre-flare coronal arcade structure seen in EIT 195 images. The observations are interpreted as evidence of a blast wave propagating through the active region coronal loop structure very early in the flare evolution.