Ellerman Bombs (EBs) and Quiet-Sun Ellerman Bombs (QSEBs) are small-scale signatures of magnetic reconnection in the lower solar atmosphere, observed in active regions and quiet-Sun areas, respectively. We investigate and compare some of their properties using coordinated multiwavelength observations from the Swedish 1-m Solar Telescope, the Interface Region Imaging Spectrograph, and the Solar Dynamics Observatory. We employ k-means clustering to identify EBs and QSEBs and perform a detailed analysis of a subset of these events. Our results show that EBs are frequently associated with opposite magnetic polarities, whereas QSEBs generally lack clear polarity signatures, likely due to limited spatial resolution. Spectral inversions using the STiC code reveal temperature enhancements of up to 1700 K in the lower chromosphere for EBs. In contrast, no clear temperature enhancement is detected for QSEBs, which may be attributed to the limited spatial resolution or insufficient wavelength sampling of the Ca II 8542 A. We further find that some EBs exhibit signatures extending to transition-region temperatures. An analysis of EBs temporal evolution reveals episodic heating, with a range of periodicities, most commonly around 6-7 minutes. In addition, we identify spatial associations between the footpoints of some spicules and EBs/QSEBs, suggesting that reconnection in these events may contribute to spicule formation. These results demonstrate similarities and differences between EBs and QSEBs and support the interpretation that small-scale magnetic reconnection contributes to heating and dynamics in EBs, while the underlying mechanism of QSEBs requires further investigation.

Coronal mass ejections (CMEs) often exhibit a three-part structure consisting of a bright inner core, an outer leading edge, and an intervening dark cavity. While the core has traditionally been attributed to prominence material, an alternative interpretation suggests it may arise from the projection effects of a twisted flux rope. We focused on limb CME events to reassess the connection between CME cores and their associated prominences in the inner corona. The CME cores were analyzed using white-light observations from the Mauna Loa Solar Observatory K-Coronagraph, while the corresponding prominence eruptions were examined using H alpha data from the Global Oscillation Network Group and 304 & Aring; images from the Atmospheric Imaging Assembly (AIA). Our results show a strong spatial correspondence between H alpha prominences and CME cores in white light, with an average image correlation of similar to 0.7, while correlations between white light and AIA 304 & Aring; are comparatively weaker (similar to 0.5). Several events could be continuously traced into the field of view of the Large Angle and Spectrometric Coronagraph Experiment (LASCO/C2), confirming the persistence of prominence material into the outer corona. We find back-extrapolating LASCO/C2 CME cores under assumptions of constant velocity and a linear trajectory can introduce large errors-up to similar to 40 degrees in inferred position angle and similar to 140 minutes in eruption time relative to their true values-underscoring the importance of observations of the inner corona for accurately constraining CME dynamics. Overall, our findings suggest that in prominence-associated CMEs, the bright cores are predominantly composed of prominence material.

Light bridges (LBs) are commonly observed in active regions and are interpreted as signatures of magnetoconvective processes in sunspots. Several studies have attempted to classify them in the past based on their morphological characteristics. Recent observations have revealed new dynamical properties of LBs, including their signatures in the upper solar atmosphere, particularly in the chromosphere, and their coupling with coronal features. In this study, we observed two cases of rare and unusual dynamics as LBs evolve. Using data from the Solar Dynamics Observatory (SDO), the evolution of the LBs is analysed, and the results are reported here. Based on our findings, we propose that the unique movements of the LBs in the observed sunspot and earlier studies could be an apparent view of the umbral core dynamics. Investigation into these dynamics through signatures in the higher atmosphere reveals a clear coupling to coronal loops and their dynamics.

Coronal mass ejections (CMEs) often exhibit a three-part structure consisting of a bright inner core, an outer leading edge, and an intervening dark cavity. While the core has traditionally been attributed to prominence material, an alternative interpretation suggests it may arise from the projection effects of a twisted flux rope. We focused on limb CME events to reassess the connection between CME cores and their associated prominences in the inner corona. The CME cores were analyzed using white-light observations from the Mauna Loa Solar Observatory (MLSO) K-Coronagraph (K-Cor), while the corresponding prominence eruptions were examined using Hα data from the Global Oscillation Network Group (GONG) and 304 Å images from the Atmospheric Imaging Assembly (AIA). Our results show a strong spatial correspondence between Hα prominences and CME cores in white light, with an average image correlation of ∼0.7, while correlations between white light and AIA 304 Å are comparatively weaker (∼0.5). Several events could be continuously traced into the Large Angle and Spectrometric Coronagraph Experiment (LASCO/C2) field of view, confirming the persistence of prominence material into the outer corona. We find back-extrapolating LASCO/C2 CME cores under constant-velocity, linear-trajectory assumptions can introduce large errors – up to 40^∘ in inferred position angle and ∼140 minutes in eruption time relative to their true values – underscoring the importance of inner-coronal observations for accurately constraining CME dynamics. Overall, our findings suggest that in prominence-associated CMEs, the bright cores are predominantly composed of prominence material.

Small-scale jet-like eruptions, such as picoflare jets and jetlets, are recognized as potential contributors to coronal heating and solar wind acceleration, yet their physical origin is still not fully established. Using ultra-high-resolution extreme ultraviolet imaging datasets from the Extreme Ultraviolet Imager on board the Solar Orbiter mission, we investigate tiny coronal jets observed off-limb in the Sun's polar regions. Visual inspection reveals that the majority of these jets exhibit distinct morphological features, including a bright spire accompanied by a dark, eruptive jet component. We analyzed 11 of these jets in detail and found that their spatial and temporal scales are comparable to previously reported jetlets, while their kinetic energies are two to three orders of magnitude lower, placing them in the picoflare regime. The bright and dark components show distinct dynamics, with the dark structures generally displaying lower speeds. A comparison with coordinated Interface Region Imaging Spectrograph data and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory data, together with 2.5D radiative-MHD simulations performed with the Bifrost code, reveals a one-to-one morphological correspondence between the dark counterparts and cool chromospheric surges accompanying the bright jet spire. This association suggests that flux emergence and magnetic reconnection at low atmospheric heights may produce coupled bright-dark structures, providing a plausible mechanism for the generation of picoflare jets. Our results demonstrate Solar Orbiter's ability to resolve the dynamics of small-scale jets and place new constraints on their origin.

Context. Spicules are elongated, jet-like structures that populate the solar chromosphere and are rooted in the lower solar atmosphere. In recent years, high-resolution observations and advanced numerical simulations have provided insights into their properties, structures, and dynamics. However, the formation mechanism of spicules, particularly the more dynamic type II spicules, which are primarily found in the quiet Sun and coronal holes, remains elusive. Aims. This study explores whether quiet Sun Ellerman bombs (QSEBs), which are ubiquitous small-scale magnetic reconnection events in the lower atmosphere, are linked to the formation of type II spicules. Methods. We analysed a high-quality 40-minute time sequence acquired with the Swedish 1-m Solar Telescope. H beta data were used to observe QSEBs and spicules, while spectropolarimetric measurements in the photospheric Fe I 6173 & Aring; line provided line-of-sight magnetic field information. We employed k-means clustering to automatically detect QSEBs and explored their potential association with spicules. Results. We identified 80 clear cases in which spicules occurred soon after the QSEB onset and not later than 30 s after the ending of the QSEBs. In all these instances, the events involved type II spicules, rapidly fading from the images. The footpoints of the spicules seemed to be rooted in QSEBs, where the onset of QSEBs often preceded the formation of the associated spicules. In addition to these clear cases, we found around 500 other events that hinted at a connection but with some ambiguities. The combined clear and ambiguous cases constitute 34% of the total detected QSEBs and a smaller percentage of the spicules in our dataset. Conclusions. Our findings suggest that a fraction of the type II spicules originate from QSEBs, supporting magnetic reconnection as a potential driving mechanism. In this context, QSEBs and spicules represent the conversion of magnetic energy into thermal and kinetic energy, respectively. We suggest that an observational programme including multiple Balmer lines would likely detect more unambiguous connections between QSEBs and spicules.

Spicules have often been proposed as substantial contributors toward the mass and energy balance of the solar corona. While their transition region (TR) counterpart has unequivocally been established over the past decade, the observations concerning the coronal contribution of spicules have often been contested. This is mainly attributed to the lack of adequate coordinated observations, their small spatial scales, highly dynamic nature, and complex multithermal evolution, which are often observed at the limit of our current observational facilities. Therefore, it remains unclear how much heating occurs in association with spicules to coronal temperatures. In this study, we use coordinated high-resolution observations of the solar chromosphere, TR, and corona of a quiet-Sun region and a coronal hole with the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) to investigate the (lower) coronal (∼1 MK) emission associated with spicules. We perform differential emission measure analysis on the AIA passbands using basis pursuit and a newly developed technique based on Tikhonov regularization to probe the thermal structure of the spicular environment at coronal temperatures. We find that the emission measure (EM) maps at 1 MK reveal the presence of ubiquitous, small-scale jets with a clear spatiotemporal coherence with the spicules observed in the IRIS/TR passband. Detailed spacetime analysis of the chromospheric, TR, and EM maps show unambiguous evidence of rapidly outward-propagating spicules with strong emission (2–3 times higher than the background) at 1 MK. Our findings are consistent with previously reported MHD simulations that show heating to coronal temperatures associated with spicules.

QSEBs are small-scale magnetic reconnection events in lower solar atmosphere. Sometimes, they exhibit transition region counterparts, known as UV brightenings. Magnetic field extrapolations suggest that QSEBs can occur at various locations of a fan-spine topology, with UV brightening occurring at null point through a common reconnection process. We aim to understand how complex magnetic configurations like interacting fan-spine topologies can cause small-scale dynamic phenomena in lower atmosphere. QSEBs were detected using k-means clustering on Hbeta observations from Swedish 1-m Solar Telescope (SST). Further, chromospheric inverted-Y-shaped jets were identified in the Hbeta blue wing. Magnetic field topologies were determined through potential field extrapolations from photospheric magnetograms using the Fe I 6173 A line. UV brightenings were detected in IRIS 1400 A SJI. We identify two distinct magnetic configurations associated with QSEBs, UV brightenings, and chromospheric inverted-Y-shaped jets. The first involves a nested fan-spine structure where, due to flux emergence, an inner 3D null forms inside fan surface of an outer 3D null with some overlap. QSEBs occur at two footpoints along the shared fan surface, with UV brightening located near the outer 3D null point. The jet originates close to the two QSEBs and follows the path of high squashing factor Q. We discuss a comparable scenario using a numerical simulation. In second case, two adjacent fan-spine topologies share fan footpoints at a common positive polarity patch, with the QSEB, along with a chromospheric inverted-Y-shaped jet, occurring at the intersection having high Q values. This study demonstrates through observational and modelling support that associated QSEBs, UV brightenings, and chromospheric inverted-Y-shaped jets share a common origin driven by magnetic reconnection between interacting fan-spine topologies.

We explore the diagnostic potential of the H α line for probing the chromospheric magnetic field using a realistic 3D radiative magnetohydrodynamic (rMHD) model. The Stokes profiles of the H α line are synthesized through full 3D radiative transfer under the field-free approximation, alongside the Ca ii 8542 Å and Fe i 6173 Å lines for comparison. The line-of-sight (LOS) magnetic fields are inferred using the weak-field approximation for the H α and Ca ii 8542 Å lines, while the Fe i 6173 Å line is analyzed through Milne-Eddington inversion techniques. The comparison between the inferred LOS magnetic field maps and the magnetic fields in the rMHD model revealed that the H α line core primarily probes the chromospheric magnetic field at log τ 500 = −5.7, which corresponds to higher layers than the Ca ii 8542 Å line core, which is most sensitive to conditions at log τ 500 = −5.1. On average, the Stokes V profiles of the H α line core form 500 km higher than those of the Ca ii 8542 Å line core. The H α polarization signals persist after adding noise, and with noise at the level of 10 −3 I c , most simulated magnetic structures remain visible. These findings suggest that spectropolarimetric observations of the H α line can provide complementary insights into the stratification of the magnetic field at higher altitudes, especially when recorded simultaneously with widely used chromospheric diagnostics such as the Ca ii 8542 Å line.

Recent high-resolution solar observations have unveiled the presence of small-scale loop-like structures in the lower solar atmosphere, often referred to as unresolved fine structures, low-lying loops, and miniature hot loops. These structures undergo rapid changes within minutes, and their formation mechanism has remained elusive. In this study, we conducted a comprehensive analysis of two small loops utilizing data from the Interface Region Imaging Spectrograph (IRIS), the Goode Solar Telescope (GST) at Big Bear Solar Observatory, and the Atmospheric Imaging Assembly and the Helioseismic Magnetic Imager on board the Solar Dynamics Observatory, aiming to elucidate the underlying process behind their formation. The GST observations revealed that these loops, with lengths of ∼3.5 Mm and heights of ∼1 Mm, manifest as bright emission structures in H α wing images, particularly prominent in the red wing. IRIS observations showcased these loops in 1330 Å slit-jaw images, with transition region (TR) and chromospheric line spectra exhibiting significant enhancement and broadening above the loops, indicative of plasmoid-mediated reconnection during their formation. Additionally, we observed upward-erupting jets above these loops across various passbands. Furthermore, differential emission measurement analysis reveals an enhanced emission measure at the location of these loops, suggesting the presence of plasma exceeding 1 MK. Based on our observations, we propose that these loops and associated jets align with the minifilament eruption model. Our findings suggest a unified mechanism governing the formation of small-scale loops and jets akin to larger-scale X-ray jets.

Context. Quiet-Sun Ellerman bombs (QSEBs) are small-scale magnetic reconnection events in the lower atmosphere of the quiet Sun. Recent work has shown that a small percentage of them can occur co-spatially and co-temporally with ultraviolet (UV) brightenings in the transition region. Aims. We aim to understand how the magnetic topologies associated with closely occurring QSEBs and UV brightenings can facilitate energy transport and connect these events. Methods. We used high-resolution H beta observations from the Swedish 1-m Solar Telescope (SST) and detected QSEBs using k-means clustering. We obtained the magnetic field topology from potential field extrapolations using spectro-polarimetric data in the photospheric Fe I 6173 & Aring; line. To detect UV brightenings, we used coordinated and co-aligned data from the Interface Region Imaging Spectrograph (IRIS) and imposed a threshold of 5 sigma above the median background on the (IRIS) 1400 & Aring; slit-jaw image channel. Results. We identify four distinct magnetic configurations that associate QSEBs with UV brightenings, including a simple dipole configuration and more complex fan-spine topologies with a 3D magnetic null point. In the fan-spine topology, the UV brightenings occur near the 3D null point, while QSEBs can be found close to the footpoints of the outer spine, the inner spine, and the fan surface. The height of the 3D null varies between 0.2 Mm and 2.6 Mm, depending on the magnetic field strength in the region. Some QSEBs and UV brightenings, though occurring close to each other, are not topologically connected with the same reconnection process. The energy released during QSEBs falls in the range 1023-1024 ergs. Conclusions. This study shows that magnetic connectivity and topological features, such as 3D null points, are crucial in linking QSEBs in the lower atmosphere with UV brightenings in the transition region.

Magnetic reconnection in the deep solar atmosphere can give rise to enhanced emission in the Balmer hydrogen lines, a phenomenon known as Ellerman bombs (EBs). It is most common to observe EBs in the H-alpha and H-beta lines. High quality shorter wavelength Balmer line observations of EBs are rare but have the potential to provide the most highly resolved view on reconnection. We evaluate the H-epsilon 3970 A line as an EB diagnostic by analyzing high quality observations in different Balmer lines. Observations of different targets and viewing angles were acquired with the Swedish 1-m Solar Telescope. These observations sample EBs in different environments: active regions, quiet Sun, and the penumbra and moat of a sunspot. We employed an automated detection method for quiet Sun EBs based on k-means clustering. Ellerman bombs in the H-epsilon line show similar characteristics as in the longer wavelength Balmer lines: enhanced intensity as compared to the surroundings, rapid variability, and flame-like morphology. In a 24 min quiet Sun time series, we detected 1674 EBs in the H-epsilon line which is 1.7 times more than in H-beta. The quiet Sun EBs measured in H-epsilon are very similar as in H-beta: they have similar lifetimes, area, brightness, and spatial distribution. Most of the EBs detected in H-epsilon are closer to the limb than their H-beta counterparts. This can be explained by the H-epsilon line core EB emission being formed higher in the atmosphere than the H-beta EB wing emission. We conclude that the H-epsilon line is well suited for studying EBs and consequently probes the dynamics of magnetic reconnection in the solar atmosphere at the smallest scales. Our findings suggests that the deep atmosphere in the quiet Sun may host more than 750,000 reconnection events with EB signature at any time. That is significantly more than what was found in earlier H-beta observations.

Alpha-synucleinopathies, characterized by extracellular alpha-synuclein (aSyn) accumulation and aggregation, have been linked to neurological disorders including Parkinson disease (PD) and multiple system atrophy (MSA). aSyn interacts with membrane proteins, phospholipids, and cholesterol, leading to membrane damage and inflammation. This interaction heightens the likelihood of aSyn engaging with P2RX7, a non-selective cationic transmembrane receptor that is primarily overexpressed in immune and neural cells. Activation of P2RX7 by aSyn is implicated in neuronal degeneration, potentially causing pore dilation and increased inflammation. However, the precise molecular mechanisms and binding sites for this interaction, as well as the conformational dynamics of P2RX7 in response to aSyn, remain unclear. We attempted to elucidate the molecular mechanisms and binding sites for P2RX7-aSyn interaction, by integrating the data curation, molecular docking, and molecular dynamics (MD) simulations coupled with structural analyses. We elucidated interactions between P2RX7 and the N-terminal domain (NTD) of aSyn using cryo-EM structures of P2RX7 in both ATP-bound and unbound states and assessed how aSyn influences P2RX7 structural and functional dynamics. Initially, the analyses revealed that aSyn interactomes are mainly involved in regulating mitochondrial homeostasis, while P2RX7 interactors are linked to receptor internalization and calcium transport. Molecular docking with six tools identified that aSyn-NTD fragments preferentially bind to the proximal region of P2RX7 transmembrane domain. Microsecond all atom MD simulations in a POPS lipid bilayer showed significant atomic fluctuations, particularly in the head region, lower body, and large loop of P2RX7 cytoplasmic domain. Secondary structure analysis indicated unfolding in regions related to pore dilation and receptor desensitization. Further by contact-based and solvent accessibility analyses, along with protein structure network (PSN) studies, we identified crucial residues involved in P2RX7-aSyn interactions. This insight deepens our understanding of how aSyn and P2RX7 interact, offering a detailed atomic view of the structural and functional changes that occur during these interactions. This understanding could advance our grasp of neurodegenerative diseases and be vital for devising future preventive and therapeutic strategies. ### Competing Interest Statement The authors have declared no competing interest.

ABSTRACT Chromospheric oscillations can give us insight into the physical environment in the solar atmosphere, both in quiet Sun and flaring conditions. Many authors have reported increases in the prevalence of 3-minute oscillations which are thought to be excited by events which impact the chromosphere such as flares. In this study, we utilized the Ca ii 8542 Å line to study the oscillatory behaviour of the chromosphere in an active region which underwent two B-class flares. We analysed oscillations in both intensity and velocity, and found different behaviours in both. Intensity oscillations were most prevalent over the umbrae of sunspots and magnetic pores in the active region, and the extent of the area which contained significant oscillations was found to decrease when comparing times after the flares to before. By measuring the evolution of the magnetic field, we found that this could be because the areas surrounding the umbrae were becoming more ‘penumbral’ with an increase to the magnetic field inclination. Velocity oscillations were found across the active region both before and after the flares but were observed clearly in areas which were brightened by the second flare. By comparing to EUV imaging, it was seen that strong chromospheric velocity oscillations with 3–4-minute periods occurred at the same time and location as a flare loop cooling 30 min after the second flare peak. This could be evidence of disturbances in the loop exciting a response from the chromosphere at its acoustic cut-off frequency.

Quiet Sun Ellerman Bombs (QSEBs) are key indicators of small-scale photospheric magnetic reconnection events. Recent high-resolution observations have shown that they are ubiquitous and that large numbers of QSEBs can be found in the quiet Sun. We aim to understand the impact of QSEBs on the upper solar atmosphere by analysing their spatial and temporal relationship with the UV brightenings observed in transition region diagnostics. We analyse high-resolution H-beta observations from the Swedish 1-m Solar Telescope and utilise k-means clustering to detect 1423 QSEBs in a 51 min time series. We use coordinated and co-aligned observations from the Interface Region Imaging Spectrograph (IRIS) to search for corresponding signatures in the 1400 A slit-jaw image (SJI) channel and in the Si IV 1394 A and Mg II 2798.8 A triplet spectral lines. We identify UV brightenings from SJI 1400 using a threshold of 5$\sigma$ above the median background. We focused on 453 long-lived QSEBs ($>1$ min) and found 67 cases of UV brightenings from SJI 1400 occurring near the QSEBs, both temporally and spatially. Temporal analysis of these events indicates that QSEBs start before UV brightenings in 57 % of cases, while UV brightenings lead in 36 % of instances. The majority of the UV brightenings occur within 1000 km from the QSEBs in the direction of the solar limb. We also identify 21 QSEBs covered by the IRIS slit, with 4 of them showing emissions in both or one of the Si IV 1394 A and Mg II 2798.8 A triplet lines, at distances within 500 km from the QSEBs in the limb direction. We conclude that a small fraction (15 %) of the long-lived QSEBs contribute to localized heating observable in transition region diagnostics, indicating a minimal role in the global heating of the upper solar atmosphere.

We present spectropolarimetric observations of an active region recorded simultaneously in the H alpha and the Ca ii 8662 & Aring; lines. The sunspot exhibits multiple structures, including a light bridge and a region where the Ca ii 8662 & Aring; line core is in emission. Correspondingly, the H alpha line core image displays brightening in the emission region, with the spectral profiles showing elevated line cores. The stratification of the line-of-sight magnetic field is inferred through nonlocal thermodynamic equilibrium multiline inversions of the Ca ii 8662 & Aring; line and the weak field approximation (WFA) over the H alpha line. The field strength inferred from the H alpha line core is consistently smaller than that inferred from inversions at log tau(500) = -4.5. However, the study finds no correlation between the WFA over the core of the H alpha line and that inferred from inversions at log tau(500) = -4.5. In regions exhibiting emission features, the morphology of the magnetic field at log tau(500) = -4.5 resembles that at log tau(500) = -1, with slightly higher or comparable field strengths. The magnetic field morphology inferred from the core of the H alpha line is also similar to that inferred from the full spectral range of the H alpha line in the emission region. The field strength inferred in the light bridge at log tau(500) = -1 is smaller than the surrounding umbral regions and comparable at log tau(500) = -4.5. Similarly, the field strength inferred in the light bridge from the WFA over the H alpha line appears lower compared to the surrounding umbral regions.

Small-scale brightenings (SBs) are commonly observed in the transition region (TR) that separates the solar chromosphere from the corona. These brightenings, omnipresent in active region patches known as "moss" regions, could potentially contribute to the heating of active region plasma. In this study, we investigate the properties of SB events in a moss region and their associated chromospheric dynamics, which could provide insights into the underlying generation mechanisms of the SBs. We analyzed the data sets obtained by coordinated observations using the Interface Region Imaging Spectrograph and the Goode Solar Telescope at Big Bear Solar Observatory. We studied 131 SB events in our region of interest and found that 100 showed spatial and temporal matches with the dynamics observed in the chromospheric H alpha images. Among these SBs, 98 of them were associated with spicules that are observed in H alpha images. Furthermore, detailed analysis revealed that one intense SB event corresponded to an Ellerman bomb (EB), while another SB event consisted of several recurring brightenings caused by a stream of falling plasma. We observed that H alpha far wings often showed flashes of strong brightening caused by the falling plasma, creating an H alpha spectral profile similar to an EB. However, 31 of the 131 investigated SB events showed no noticeable spatial and temporal matches with any apparent features in H alpha images. Our analysis indicated that the predominant TR SB events in moss regions are associated with chromospheric phenomena primarily caused by spicules. Most of these spicules display properties akin to dynamic fibrils.

ADITYA-L1 is India′s first dedicated mission to observe the Sun and its atmosphere from a halo orbit around L1 point. Visible emission line coronagraph (VELC) is the primary payload on board Aditya-L1 to observe the Sun’s corona. VELC is designed as an internally occulted reflective coronagraph to meet the observational requirements of wide wavelength band and the field of view close to the solar limb (1.05 RSun). Images of the solar corona in continuum and spectra in three emission lines 5303Å [Fe xiv], 7892Å [Fe xi] and 10747Å [Fe xiii] obtained with high cadence are to be analyzed using software algorithms automatically. A reasonable part of these observations will be made in a synoptic mode in which the data are processed through a standard pipeline and the resulting products will be made available for public use. The procedure involves the calibration of instrument and detectors, converting the images into the FITS format, correcting the images and spectra for the instrumental effects, and aligning the images (in terms of position angles and image scales) etc. Then, develop image processing algorithms to detect the occurrence of energetic events using continuum images. Also derive physical parameters, such as temperature and velocity structure of solar corona using emission line observations. Here, we describe the calibration of detectors and the development of software algorithms to detect the occurrence of CMEs and analyze the spectroscopic data.

We investigated the diagnostic potential of the Stokes V profile of the H α line to probe the chromospheric line-of-sight (LOS) magnetic field ( B LOS ) by comparing the B LOS inferred from the weak field approximation (WFA) with that inferred from the multiline inversions of the Ca ii 8542 Å, Si i 8536 Å, and Fe i 8538 Å lines using the STiC inversion code. Simultaneous spectropolarimetric observations of a pore in the Ca ii 8542 Å and H α spectral lines obtained from the SPINOR at the Dunn Solar Telescope on 2008 December 4 are used in this study. The WFA was applied on the Stokes I and V profiles of H α line over three wavelength ranges, viz., around line core (Δ λ = ±0.35 Å), line wings (Δ λ = [−1.5, −0.6], and [+0.6, +1.5] Å), and full spectral range of the line (Δ λ = ± 1.5 Å) to derive the B LOS . We found the maximum B LOS strengths of ∼+800 and ∼+600 G at log τ 500 = −1 and −4.5, respectively, in the pore. The morphological map of the B LOS inferred from the H α line core is similar to the B LOS map at log τ 500 = −4.5 inferred from multiline inversions. The B LOS map inferred from the H α line wings and full spectral range have a similar morphological structure to the B LOS map inferred at log τ 500 = −1. The B LOS estimated from H α using WFA is weaker by a factor of ≈0.53 than that of inferred from the multiline inversions.

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