Solar Time Research Articles

Expanded glass sphere/lauryl alcohol composite in gypsum: Physico-mechanical properties, energy storage performance and environmental impact assessment

In recent years, thermal energy storage systems, which are a promising solution to improve the thermal comfort of buildings and reduce energy demand, are a critical issue. This study aims to develop a new shape-stable gypsum composite using expanded glass sphere (EGS) and lauryl alcohol (LA) and analyses its thermal performances. For this purpose, EGS was impregnated with LA in different mass fractions (25 and 50%) by direct impregnation technique. DSC results exposed that melting temperature and melting enthalpy of shape-stable EGS/LA composite were 20.97 °C and 83.1 J/g, respectively. FTIR investigations confirmed the existence of well chemical compatibility between EGS and LA. TGA analysis revealed that the operating temperature of EGS/LA was considerably lower than its thermal degradation temperature. While incorporation of EGS and EGS/LA composite increases water absorption and porosity; caused a decrease in compressive strength, dry unit weight and ultrasound pulse velocity properties. EGS/Gypsum composite with LA (50%) provided a warmer room temperature for more than 12 h between midnight and solar noon hours. It achieved about 2 ℃ warmer room during these hours. After solar noon hours, proposed composite attained about 3.6 ℃ cooler room center temperatures. It provided cooler indoor temperatures for more than 5 h. A warmer indoor temperature was observed for EGS/Gypsum composite with LA (50%) after 18:00 until midnight to be 2 ℃. It can provide a carbon emission saving of around 3–23.2 kg-CO2/kWh, depending on fuel type for a wall cover made of EGS/Gypsum with LA.

A novel adaptive approach for improvement in the estimation of hourly diffuse solar radiation: A case study of China

Liu & Jordan–type models are still widely used to estimate diffuse radiation in various regions because of their simplicity. This paper proposes an adaptive approach of combining the grouping of kt–k data points with Liu & Jordan–type models to estimate the hourly diffuse radiation more accurately. This study was conducted using hourly radiation data measured in three regions in China (Shanghai, Xi'an, and Lhasa). The main novelties reported herein are the introduction of α as a constraint indicator and the proposal of a criterion for grouping kt–k data points. Grouping models, which adopted the functional form of cubic polynomials, were established in three regions based on the grouped data. Compared with the all-data model results, the percentage of mean absolute bias error (MABE%) and relative root mean square error (RMSE%) for the grouping model decreased by approximately 4% in Shanghai and Xi'an and 6% in Lhasa. Furthermore, weather condition analysis showed that the grouping models had the best adaptability on overcast days, followed by cloudy days and sunny days. A similar analysis was performed for solar time, with the best adaptability occurring at sunrise and sunset and the worst occurring at 9 am. The results also suggest that similar working procedures could contribute to hourly diffuse radiation estimation in other fields.

Solar Absorptivity Degradation of Spacecraft Materials Due to UV and Charged Particles in the Gateway Environment

Gateway will be an outpost in cislunar space designed to survive a 15-year mission to support human Moon landings and future deep space exploration. The Gateway Passive Thermal Control System (PTCS) Group has identified charged particle and UV degradation of potential Gateway materials as a knowledge gap for the Near Rectilinear Halo Orbit (NRHO) and transit environment, especially the slow spiral transit planned for the first two modules. Solar absorptivity degradation is important to quantify because the end-of-life absorptivity impacts thermal performance of the system. To address this, ground testing has been completed at NASA Goddard Space Flight Center in which potential Gateway materials, including radiators, multi-layer insulation (MLI), and structural materials are subjected to the expected transit plus 15-year on-orbit charged particle fluence (9.86x1015 protons/cm2 at 2.5 keV and 3.1x1016 electrons/cm2 at 10 keV) and 5093 Equivalent Solar Hours (ESH). Reflectivity of a single sample of each material was measured in atmosphere and in vacuum inside the chamber after exposure to incremental levels of ESH and charged particle fluence. Increase in absorptivity of most samples were seen throughout the test including large differences in absorptivity of materials of the same category. Future planned testing will validate these results and include additional materials of interest.

Exploring the Synergy of Integration: Assessing the Performance of Hydraulic Storage and Solar Power Integration in Kirkuk city

This research investigates the performance of integrated system combining of hydraulic storage and solar power in Iraq. A photovoltaic-water pumping system was designed to store solar energy in the form of water in tank at a height of 6 mm. The study evaluates the influence of solar radiation level and pumping time in determining the amount of energy stored. During clear days in March, 175 minutes was taken to pump a total of 3400 liters of water in the case of the fixed PV panel, while when using the tracker, the time is reduced to 165 minutes for filling the tank with the same quantity of water due to the increase in the pumping capacity in the case of the tracker. During a cloudy day in the same month, the same quantity of water was pumped in 230 minutes. The stored water was then utilized to generate electricity, with varying flow rates based on the desired power output .The highest produced power was obtained by 42.9 W at a 42 lit / sec water flow rate, and the lowest power obtained by 23.2 W at a minimum water flow rate of 25 lit / sec. Moreover, the system's cost-effectiveness is enhanced by employing a direct current pump which can be used without the need for the inverter or batteries. These findings provide good understanding for the integrating of the hydraulic storage and solar power systems, offering potential solutions for sustainable energy generation in Iraq.

The Mammalian Circadian Time-Keeping System.

Our physiology and behavior follow precise daily programs that adapt us to the alternating opportunities and challenges of day and night. Under experimental isolation, these rhythms persist with a period of approximately one day (circadian), demonstrating their control by an internal autonomous clock. Circadian time is created at the cellular level by a transcriptional/translational feedback loop (TTFL) in which the protein products of the Period and Cryptochrome genes inhibit their own transcription. Because the accumulation of protein is slow and delayed, the system oscillates spontaneously with a period of ∼24 hours. This cell-autonomous TTFL controls cycles of gene expression in all major tissues and these cycles underpin our daily metabolic programs. In turn, our innumerable cellular clocks are coordinated by a central pacemaker, the suprachiasmatic nucleus (SCN) of the hypothalamus. When isolated in slice culture, the SCN TTFL and its dependent cycles of neural activity persist indefinitely, operating as "a clock in a dish". In vivo, SCN time is synchronized to solar time by direct innervation from specialized retinal photoreceptors. In turn, the precise circadian cycle of action potential firing signals SCN-generated time to hypothalamic and brain stem targets, which co-ordinate downstream autonomic, endocrine, and behavioral (feeding) cues to synchronize and sustain the distributed cellular clock network. Circadian time therefore pervades every level of biological organization, from molecules to society. Understanding its mechanisms offers important opportunities to mitigate the consequences of circadian disruption, so prevalent in modern societies, that arise from shiftwork, aging, and neurodegenerative diseases, not least Huntington's disease.

Diurnal Variation Characteristics of Clouds and Precipitation during the Summer Season in Two Typical Climate Regions of the Tibetan Plateau

Mêdog and Nagqu are two typical climate regions of the Tibetan Plateau, with different atmospheric conditions and local orography. This may lead to different diurnal variation patterns of clouds and precipitation. This paper investigates the diurnal variations of clouds and precipitation in Mêdog and Nagqu, using ground-based measurements from Ka-band cloud radar and a Particle Size and Velocity (PARSIVEL) disdrometer. High frequencies of cloud cover and precipitation occur from 23:00 local solar time (LST) to 05:00 LST in Mêdog, while low frequencies appear from 11:00 LST to 17:00 LST. The occurrence frequencies in Nagqu maintain high values from 13:00 LST to 21:00 LST. In terms of mean rain rate, heavier rainfall appears in the evening and at night in Mêdog, with peaks at 00:00 LST and 18:00 LST, respectively. In Nagqu, the heaviest rainfall occurs at 12:00 LST. In addition, the afternoon convective rainfall in Nagqu is characterized by a much higher concentration of large drops, which can be classified as continental-like. The morning rainfall has the lowest concentration of large drops and can be classified as maritime-like. Finally, the mechanisms of diurnal variations in the two regions are discussed. The diurnal cycle of clouds and precipitation in Mêdog may be associated with the nocturnal convergence of moisture flux and mountain–valley wind circulation. Diurnal variations in Nagqu have a high correlation with the diurnal cycle of solar radiation. The high nocturnal frequency of clouds and precipitation in the two regions at night is closely related to the convergence of moisture flux.

Renewable Energy Powered Membrane Technology: Energy Buffering Control to Reduce Shut‐Down Events and Enhance System Resilience under Different Solar Days (Adv. Sustainable Syst. 7/2023)

Renewable Energy Powered Membrane Technology: Energy Buffering Control to Reduce Shut‐Down Events and Enhance System Resilience under Different Solar Days (Adv. Sustainable Syst. 7/2023)

Time Series of Space Observations: Analysis of Local Meteorological and Solar Series

A range of issues related to the results of the analysis of some meteorological and solar series of satellite observations in the Kara-Dag area (Crimea) is considered. A qualitative and quantitative picture of changes in the total insolation falling on the Earth’s surface, air temperature at a height of 2 m, and the Earth’s surface temperature in Kara-Dag over the past 38 years is presented. A numerical model has been constructed that makes it possible to predict the most powerful fluctuation with a period of 1 year in the analyzed data. The following methods were used in the work: the method of wavelet analysis, statistical methods for extracting Gaussian and non-Gaussian noise, an iterative method for constructing and estimating the accuracy of model approximations. Coherent variations in the analyzed and some global geodynamic and solar time series were established using two-channel autoregressive analysis. A qualitative characteristic of the process of changing the main variations in the analyzed time series was obtained using the analysis of phase trajectories on the Poincaré plane.

PERFORMANCE EVALUATION OF SOLAR PHOTOVOLTAIC PANEL MOUNTED ON SLOPED CORRUGATED METAL SHEET ROOF IN KANO STATE NORTHWEST NIGERIA

Installation of solar photovoltaic system on roof has advantages of proper utilization of space, help in avoiding shading effects and reduction of dust accumulation on the panels. However, electrical efficiency and lifespan of solar photovoltaic panel tends to decrease due to the increase in surface temperature above the operation temperature of the panels due to its contact with the roofing sheets. The performance of solar photovoltaic panels was experimentally investigated on corrugated metal sheet (CMS) roof at four different heights (0, 100, 200, and 300mm). Four polycrystalline silicon photovoltaic panels of 10 watts each were selected from the same manufacturer. The temperatures on the roof and on the photovoltaic panels’ surfaces were measured at different solar hours. Also, the outputs of the solar panels together with the irradiance available were measured at same hours using an electronic data logger and imported to an Excel software. Irradiance variation, gap between roof and photovoltaic panels, and heating effect on panels were found to be the parameters affecting the photovoltaic system’s performance. The highest temperature attained by the photovoltaic panel is when it was directly mounted on the roof as 76.5°C while the other photovoltaic panels mounted at a gap height of 100mm, 200mm and 300mm attained the highest temperature of 71.8oC, 69,6oC and 68.0oC respectively. The panels’ extra heat was originating from CMS roof vicinity. Output powers from the panels were unequal throughout the experiment whilst exhibited similar behavior. The panels’ temperature dropped...

Solar clock and school start time effects on adolescents' chronotype and sleep: A review of a gap in the literature.

Circadian rhythms are entrained by external factors such as sunlight and social cues, but also depend on internal factors such as age. Adolescents exhibit late chronotypes, but worldwide school starts early in the morning leading to unhealthy sleep habits. Several studies reported that adolescents benefit from later school start times. However, the effect of later school start time on different outcomes varies between studies, and most previous literature only takes into consideration the social clock (i.e. local time of school starting time) but not the solar clock (e.g. the distance between school start time and sunrise). Thus, there is an important gap in the literature: when assessing the effect of a school start time on chronotype and sleep of adolescents at different locations and/or seasons, the solar clock might differ and, consistently, the obtained results. For example, the earliest school start time for adolescents has been suggested to be 08:30 hours, but this school start time might correspond to different solar times at different times of the year, longitudes and latitudes. Here, we describe the available literature comparing different school start times, considering important factors such as geographic position, nationality, and the local school start time and its distance to sunrise. Then, we described and contrasted the relative role of both social and solar clocks on the chronotype and sleep of adolescents. As a whole, we point and discuss a gap in literature, suggesting that both clocks are relevant when addressing the effect of school start time on adolescents' chronotype and sleep.

Prediction Aerospace Software to Detect Solar Activity and the Fast Tracking of Solar Activity Using Remote Sensing Instruments in Orbit

At present, solar remote sensing instruments face problems regarding the short detection time for solar activity and the need to preheat the electronics before detection. The accurate orbit prediction function ensures that the maximum error of the payload electronics system preheating time is less than 8 s, enabling the electronics to obtain stable and reliable solar remote sensing data, and allowing the prediction function to adapt to the changes in preheating time and the limit position of turntable rotation. To achieve the complete detection of solar activity by a payload in orbit, a turntable with two directions of rotation was accurately controlled to achieve rapid capture and track the Sun’s activity, and the delay time for tracking the Sun successfully was less than 8 s to ensure that the payload made full use of the solar detection time for full detection. The turntable’s tracking error was less than 0.002°, allowing the payload to obtain high-precision solar remote sensing data in orbit. The above methods enable the payload to realize the complete, stable, and high-precision detection of solar activity in orbit for wavelengths ranging approximately from 165 nm to 2400 nm.

An attention-based Bayesian sequence to sequence model for short-term solar power generation prediction within decomposition-ensemble strategy

The utilization of renewable energy has attracted much attention with the deterioration of the environment. Solar energy is widely distributed and has huge reserves. But, solar energy is also volatile and intermittent. This brings difficulties to the large-scale grid connection of solar energy and the distribution of power resources. The key to solve this problem is to provide accurate and stable short-term prediction for solar power generation. For this purpose, we present an attention-based Bayesian sequence to sequence (Seq2Seq) model within decomposition-ensemble strategy. Firstly, an influential factors analysis is performed on the data about meteorological conditions, operation status of the photovoltaic panels and historical solar power generation sequences to obtain the optimal combination of the influential factors. Secondly, this paper proposes a novel decomposition-ensemble framework based on complete ensemble empirical mode decomposition with adaptive noise and independent component analysis to mine the intrinsic modes of the solar power generation time series. Thirdly, this paper presents an attention-based Bayesian Seq2Seq method for modeling the relationships between solar power generation and influential factors. Using a real-world dataset from State Administration of Electricity Investment Science and Technology of China, a case study, comparative analysis and robustness checks are conducted, through which the contributions of the methods in the proposed model and the superior performance of the model are demonstrated.

Long-term forcing of the Sun’s coronal field, open flux, and cosmic ray modulation potential during grand minima, maxima, and regular activity phases by the solar dynamo mechanism

ABSTRACT Magnetic fields generated in the Sun’s interior by the dynamo mechanism drive solar activity over a range of time-scales. Direct sunspot observations exist for a few centuries; reconstructed variations based on cosmogenic isotopes in the solar open flux and cosmic ray flux exist over thousands of years. While such reconstructions indicate the presence of extreme solar activity fluctuations in the past, causal links between millennia scale dynamo activity, consequent coronal field, solar wind, open flux and cosmic ray flux variations remain elusive; a lack of coronal field observations compounds this issue. By utilizing a stochastically forced solar dynamo model and potential field source surface extrapolation, we perform long-term simulations to illuminate how dynamo generated magnetic fields govern the structure of the solar corona and the state of the heliosphere – as indicated by variations in the open flux and cosmic ray modulation potential. We establish differences in the nature of the large-scale structuring of the solar corona during grand maximum, minimum, and regular solar activity phases and simulate how the open flux and cosmic ray modulation potential vary across these different phases of activity. We demonstrate that the power spectrum of simulated and observationally reconstructed solar open flux time series are consistent with each other. Our study provides the theoretical foundation for interpreting long-term solar cycle variations inferred from cosmogenic isotope based reconstructions and establishes causality between solar internal variations to the forcing of the state of the heliosphere.

Performance evaluation of PV panels for green HHO gas generation: Energy, exergy, and economic investigation

The paper aim is to design and fabricate of solar-powered alkaline water electrolyzer to produce hydroxy gas (HHO) flow with enhanced efficiency. Oxyhydrogen gas was yielded by the electrolysis of water utilizing various NaOH concentrations of 5, 10, 15 and 20%. Based on the solar radiation peak time at 12:00 p.m., the increase of solar intensity from 502 W/m2 to 1000 W/m2 (from 08:00 AM to 12:00 PM) led to the current and voltage increases by about 700% and 450%, respectively. Cell efficiency increase was from 61% to 69% by about 13% increase ratio. The output of HHO increases with cell gap between 1 and 3 mm. For temperatures between 30 °C and 60 °C, HHO generation declines at the gaps of cells between 4 and 7 mm. At the same operating temperature, the cells gap of 1, 3, 4, and 7 mm produced flow rates of 928, 975, 960, and 925 ml/min, respectively. After 30 min, the rate of HHO achieves the maximum values of 866, 985, 1090, and 1140 ml/min at NaOH concentrations of 5, 10, 15, and 20%. The simplicity, ease of assembly, and manufacture of the dry cell made it appealing. The HHO dry cell is affordable, made from readily available components, and adaptable to engines that receive their power from solar panels. The cost per liter to produce HHO varies between 0.437 and 0.575 $.

Experimental Thermal Performance of Phase Change Material Embedded Solar Air Heater Employing Impinging Stable Air Jet Array Presenting High Power and Energy Density

Abstract This experimental thermal performance investigation presents that the hot air at a significantly high temperature, and simultaneously at high power density and energy density of phase change material (PCM) can be obtained utilizing a novel design of PCM embedded solar air heater employing impinging stable air jet array. Investigation is carried out following two main objectives, i.e., to obtain (i) instant and (ii) long thermal backups. In the reported design configuration, impinging stable air jets on absorber plate are obtained by reducing the flow path of expelled air from upstream air jets that increased the heat transfer rate to air and consequently instant thermal backup. Although, the use of wavy PCM unit provides instant and long thermal backup by increasing heat transfer area that augments the heat transfer to air and the collection of solar radiations, respectively. Moreover, the present study is extended as follows, (i) the use of shutter on glass cover to increase thermal performance during nocturnal hours, (ii) charging of PCM till the maximum solar radiation hours and use of the stored energy during nocturnal hours, (iii) thermal performance analysis to reveal instant thermal backup, (iv) thermal performance investigation during variable weather conditions, and (v) thermal performance investigation for low ambient air temperature. The obtained results revealed that for the unit collector area, significant thermal backup of about 6 h at a temperature rise of ≥5 °C can be obtained by utilizing the above-mentioned provisions in this research.

Solar-energy-driven CuOCo3O4@CP nanocomposite thin-film: an efficient photocatalyst for acid red 73 degradation

Abstract Nowadays, solar photocatalysis has received a lot of attention as an effective method for environmental remediation. During the last few decades, textile dyeing and finishing industries produced a large quantity of wastewater discharges with complex compositions. Herein, we first reported CuOCo3O4@CP was successfully fabricated using a cost-effective, eco-friendly, extremely reliable spray pyrolysis method. Crystal structure, surface texture, elemental purity and optical properties of fabricated thin-films were analyzed using XRD, SEM, EDX, UV–vis spectrophotometers, DLS and FTIR techniques. Functional parameters such as initial dye pH, solar irradiation time, oxidant concentration and initial acid red 73 (AR 73) dye concentration were optimized using statistical design response surface methodology (RSM). The estimation of AR 73 dye was assessed by UV–vis spectroscopy and FTIR study. Resultantly, >94 % AR 73 dye degradation was achieved using CuOCo3O4@CP under optimum conditions. Meanwhile, water standard parameters reduction like COD (76 %), BOD (64 %), and TOC (60 %) were also executed. In the end, the most important factor reusability of fabricated CuOCo3O4@CP was also reviewed up to 20 cycles and CuOCo3O4@CP was sustained up to 10 cycles without any loss of efficiency; 23 % deduction was observed till 20 cycles. Hence, fabricated CuOCo3O4@CP thin-film has been considered a novel photocatalyst for effluent treatment.

The 17 April 2021 widespread solar energetic particle event

Context.A complex and long-lasting solar eruption on 17 April 2021 produced a widespread solar energetic particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere that covered distances to the Sun from 0.42 to 1 au: BepiColombo, Parker Solar Probe, Solar Orbiter, STEREO A, and near-Earth spacecraft. The event was the second widespread SEP event detected in solar cycle 25, and it produced relativistic electrons and protons. It was associated with a long-lasting solar hard X-ray flare that showed multiple hard X-ray peaks over a duration of one hour. The event was further accompanied by a medium-fast coronal mass ejection (CME) with a speed of 880 km s−1that drove a shock, an extreme ultraviolet wave, and long-lasting and complex radio burst activity that showed four distinct type III burst groups over a period of 40 min.Aims.We aim to understand the reason for the wide spread of elevated SEP intensities in the inner heliosphere as well as identify the underlying source regions of the observed energetic electrons and protons.Methods.We applied a comprehensive multi-spacecraft analysis of remote-sensing observations and in situ measurements of the energetic particles and interplanetary context to attribute the SEP observations at the different locations to the various potential source regions at the Sun. We used an ENLIL simulation to characterize the complex interplanetary state and its role in the energetic particle transport. The magnetic connection between each spacecraft and the Sun was determined using ballistic backmapping in combination with potential field source surface extrapolations in the lower corona. Using also a reconstruction of the coronal shock front, we then determined the times when the shock establishes magnetic connections with the different observers. Radio observations were used to characterize the directivity of the four main injection episodes, which were then employed in a 2D SEP transport simulation to test the importance of these different injection episodes.Results.A comprehensive timing analysis of the inferred solar injection times of the SEPs observed at each spacecraft suggests different source processes being important for the electron and proton events. Comparison among the characteristics and timing of the potential particle sources, such as the CME-driven shock or the flare, suggests a stronger shock contribution for the proton event and a more likely flare-related source for the electron event.Conclusions.In contrast to earlier studies on widespread SEP events, we find that in this event an important ingredient for the wide SEP spread was the wide longitudinal range of about 110° covered by distinct SEP injections, which is also supported by our SEP transport modeling.

Dynamical Heating in the Martian Thermosphere

AbstractDynamical heating and cooling are prominent features of planetary atmospheres resulting in thermospheric structures on Venus, Earth and Mars. The purpose of this study is to determine the location and amplitude of localized heating regions in the Martian thermosphere, confirm that they occur in regions of wind convergence and compare the observed dynamical heating with that predicted by a global thermospheric model. This investigation uses several years of data from the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission including observations made by the Neutral Gas and Ion Mass Spectrometer (NGIMS) as well as the Extreme Ultraviolet Monitor (EUVM). Specifically, the analysis focuses on several years of horizontal wind, temperature, and composition data. EUVM measurements provide a solar forcing context for the neutral thermosphere data sets and aid in the statistical analysis. Statistical results are compared with two versions of the Mars Global Ionosphere Thermosphere (M‐GITM) global circulation model: one that includes gravity wave parametrization and a version without gravity wave effects. Data analysis indicates that heating features exist around 2–3 and 17–18 local solar time. These locations coincide with regions of converging winds and are in better agreement with M‐GITM when a gravity wave parametrization is included in the model. An oscillation in the observed wind field also results in convergence and a density enhancement near 15 local time. While a similar oscillation is reproduced by the model, the amplitude is much lower than observed and may be a result of modeled zonal winds that are too low.

Pyodine: an open, flexible reduction software for iodine-calibrated precise radial velocities

Context. Many telescopes use an iodine (I2) absorption cell to measure precise radial velocities (RVs), but their data reduction pipelines are all tailored to their respective instrumental characteristics and not openly accessible. Aims. For existing and future projects dedicated to measuring precise RVs, we have created an open-source, flexible data reduction software to extract RVs from échelle spectra via the I2 cell method. The software, called pyodine, is completely written in Python and has been built in a modular structure to allow for easy adaptation to different instruments. Methods. We present the fundamental concepts employed by pyodine, which build on existing I2 reduction codes, and give an overview of the software’s structure. We adapted pyodine to two instruments, Hertzsprung SONG located at Teide Observatory (SONG hereafter) and the Hamilton spectrograph at Lick Observatory (Lick hereafter), and demonstrate the code’s flexibility and its performance on spectra from these facilities. Results. Both for SONG and Lick data, the pyodine results generally match the RV precision achieved by the dedicated instrument pipelines. Notably, our code reaches a precision of roughly 0.69 m s−1 on a short-term solar time series of SONG spectra, and confirms the planet-induced RV variations of the star HIP 36616 on spectra from SONG and Lick. Using the solar spectra, we also demonstrate the capabilities of our software in extracting velocity time series from single absorption lines. A probable instrumental effect of SONG is still visible in the pyodine RVs, despite being a bit damped as compared to the original results. Conclusions. With pyodine we prove the feasibility of a highly precise, yet instrument-flexible I2 reduction software, and in the future the code will be part of the dedicated data reduction pipelines for the SONG network and the Waltz telescope project in Heidelberg.

The Solar Upper Transition Region Imager (SUTRI) Onboard the SATech-01 Satellite

The Solar Upper Transition Region Imager (SUTRI) onboard the Space Advanced Technology demonstration satellite (SATech-01), which was launched to a Sun-synchronous orbit at a height of ∼500 km in 2022 July, aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne vii 46.5 nm spectral line with a filter width of ∼3 nm. SUTRI employs a Ritchey–Chrétien optical system with an aperture of 18 cm. The on-orbit observations show that SUTRI images have a field of view of ∼ 41.′6 × 41.′6 and a moderate spatial resolution of ∼8″ without an image stabilization system. The normal cadence of SUTRI images is 30 s and the solar observation time is about 16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period. Approximately 15 GB data is acquired each day and made available online after processing. SUTRI images are valuable as the Ne vii 46.5 nm line is formed at a temperature regime of ∼0.5 MK in the solar atmosphere, which has rarely been sampled by existing solar imagers. SUTRI observations will establish connections between structures in the lower solar atmosphere and corona, and advance our understanding of various types of solar activity such as flares, filament eruptions, coronal jets and coronal mass ejections.