Solar Activity Fluctuations Research Articles

RESEARCH ON THE OPERATION OF THE ELECTROMECHANICAL SYSTEM OF AN AUTONOMOUS PHOTOELECTRIC PUMPING STATION

The work is dedicated to the investigation and analysis of the operation of the electromechanical system of an autonomous photovoltaic pumping station. Photovoltaic pumping stations are essential components of sustainable development, enabling efficient utilization of solar energy for independent water pumping. The study provides a detailed analysis of the structure and operation principles of the photovoltaic pumping station. Key components of the system, such as solar panels, electronic controllers, electromechanical pumps, and energy storage, were studied. Various methods for maximizing energy output from solar panels and optimizing the efficiency of pumping systems were examined. The research results revealed that the effective functioning of the photovoltaic pumping station depends on the precise balance of electromechanical components, optimal utilization of solar energy, and efficient management of electronic systems. Recommendations were put forth for improving the system's efficiency and reliability. Within the study, it was established that a crucial factor in the successful function of the photovoltaic pumping station is the selection of the optimal type of solar panels and their positioning to ensure maximum solar energy collection. The issue of storing excess energy to maintain system stability during periods of limited solar irradiation was also addressed. Moreover, the study included modeling and experimental research of various operational modes of the pumping station, including load variation and solar activity fluctuations. This provided crucial data regarding the dynamics and compliance of system operation with planned parameters. An important aspect of the research was evaluating the efficiency and economic viability of the photovoltaic pumping station in comparison with traditional energy sources for water supply. It was found that in some cases, the use of photovoltaic energy could be a more economically advantageous and environmentally cleaner solution. Overall, the results of this scientific work hold significant practical value for sustainable energy development and the utilization of renewable energy sources. The investigation of the operation of the electromechanical system of an autonomous photovoltaic pumping station contributes to a deeper understanding of the technological, economic, and environmental aspects of such systems. In conclusion, this research provides a deeper insight into the functioning principles of autonomous photovoltaic pumping stations and can serve as a foundation for further studies in the field of renewable energy utilization.

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.

Forecasting solar energetic proton integral fluxes with bi-directional long short-term memory neural networks

Solar energetic particles are mainly protons and originate from the Sun during solar flares or coronal shock waves. Forecasting the Solar Energetic Protons (SEP) flux is critical for several operational sectors, such as communication and navigation systems, space exploration missions, and aviation flights, as the hazardous radiation may endanger astronauts’, aviation crew, and passengers’ health, the delicate electronic components of satellites, space stations, and ground power stations. Therefore, the prediction of the SEP flux is of high importance to our lives and may help mitigate the negative impacts of one of the serious space weather transient phenomena on the near-Earth space environment. Numerous SEP prediction models are being developed with a variety of approaches, such as empirical models, probabilistic models, physics-based models, and AI-based models. In this work, we use the bidirectional long short-term memory (BiLSTM) neural network model architecture to train SEP forecasting models for three standard integral GOES channels (>10 MeV, >30 MeV, >60 MeV) with three forecast windows (1-day, 2-day, and 3-day ahead) based on daily data obtained from the OMNIWeb database from 1976 to 2019. As the SEP variability is modulated by the solar cycle, we select input parameters that capture the short-term, typically within a span of a few hours, and long-term, typically spanning several days, fluctuations in solar activity. We take the F10.7 index, the sunspot number, the time series of the logarithm of the X-ray flux, the solar wind speed, and the average strength of the interplanetary magnetic field as input parameters to our model. The results are validated with an out-of-sample testing set and benchmarked with other types of models.

Numerical simulation of stratospheric QBO impact on the planetary waves up to the thermosphere

With the help of numerical simulation, a detailed analysis of the dynamical effect of the stratospheric quasi-biennial oscillation (QBO) of the equatorial zonal wind on the planetary waves (PWs) up to thermospheric heights is carried out for the first time. The 3-dimensional nonlinear mechanistic model of middle and upper atmosphere (MUAM) is used, which is capable of simulating the general atmospheric circulation from the surface up to 300–400 km altitude. The amplitudes of stationary and westward travelling PWs with periods from 4 to 10 days are calculated based on ensembles of model simulations for conditions corresponding to the easterly and westerly QBO phases. Fluxes of wave activity and refractive indices of the atmosphere are calculated to analyze the detailed behavior of the PWs. The important result to emerge is that the stratospheric QBO causes statistically significant changes in the amplitudes of individual wave components up to 25% in the mesosphere-lower thermosphere and 10% changes above 200 km. This change in wave structures should be especially noticeable in the atmosphere during periods of low solar activity, when the direct contribution of solar activity fluctuations is minimized. Propagating from the troposphere to the upper atmosphere, PWs contribute to the propagation of the QBO signal not only from the equatorial region to extratropical latitudes, but also from the stratosphere to the thermosphere. The need for a detailed analysis of large-scale wave disturbances in the upper atmosphere and their relationship with the underlying layers is due, in particular, to their significant impact on satellite navigation and communication systems, which is caused by amplitude and phase fluctuations of the radio signal.

Coherence of Fluctuations of Components of the Global Climate System with Slow Fluctuations of Solar Activity according to Ground-Based and Satellite Observations

Coherence of Fluctuations of Components of the Global Climate System with Slow Fluctuations of Solar Activity according to Ground-Based and Satellite Observations

Climate History of the Principality of Transylvania during the Maunder Minimum (MM) Years (1645–1715 CE) Reconstructed from German Language Sources

This paper deals with the climate in the former Grand Duchy of Transylvania, now one of the three major geographical provinces of Romania, within the so-called Maunder Minimum (MM) (1645–1715), an astrophysically defined part of the Little Ice Age (LIA), which was characterized by reduced solar activity. The historical data from Transylvania are compared with that from Germany, Austria and Switzerland. This comparison for the period 1645–1715 shows good agreement but also reveals geographic characteristics of the region. For the first time, we present here a comparison between the four geographic areas in text and tabular form. Quotes from mostly German-language sources are reproduced in English translation. The results clearly help to identify regional climatic differences during the MM. Furthermore, we examine for a longer period (1500–1950) the extent to which the climate of Transylvania might have been affected by long-term fluctuations in solar activity, as deduced from isotopic reconstructions from ice cores. This way we compared astrophysical conditions with climatological ones in order to see if any probable relations do indeed show up. This comparison suggests a certain solar influence but the agreement is not very pronounced. Future investigation in a pan-European context is needed to reach reliable statements. Some results are unexpected—such as an unusually small number of severe winters during the last decades of the MM, where extreme cold was restricted to a few years, like the extreme winters 1699/1700 and 1708/1709.

Decadal Temperature Variations Over the Northwestern Tibetan Plateau Deduced From a 489‐Year Ice Core Stable Isotopic Record

AbstractInformation on decadal temperature variations over the northwestern Tibetan Plateau (TP) is still very limited due to a lack of long‐term instrumental data. In this paper, we present a 489‐year (1524–2012 A.D.) reconstruction of annual mean temperature for the northwestern TP using the δ18O record of a 58.82 meter‐long shallow ice core retrieved on the Chongce ice cap in the western Kunlun Mountains. The reconstructed temperature exhibits significant decadal variations, which were mainly driven by the Atlantic Multidecadal Variability. Decadal temperature variation during the Little Ice Age (LIA) is significantly larger than that during the post‐industrial warming period, possibly due to such external forcing as large fluctuations of solar activity and frequent major volcanic eruptions during the LIA. In addition, our reconstruction shows that the recent warming since the 1980s is moderate, comparable to an earlier warm interval in the mid‐20th century, which may partly explain the relatively stable status of glaciers in this region since 1970s.

The Influence of Solar Activity Rhythms on Precipitation Cycles during Climate Change in Central Yakutia

The study of global climate warming remains open the questions about predicting process patterns and the used methods. The impact of solar activityon the Earth natural processes is being studied. The revealed features of solar activity fluctuations are consequences of the physics of the phenomenon itself, as well as delays in reactions to fluctuations in various geophysical layers of the Earth. Eleven-year cycles of precipitation dynamics observed at the Yakutsk meteorological station in comparison with solar activity cycles are described. The total number of cycles, according to the weather station, for the period from 1934 to 2018 is eleven. They are compared to eight solar activity cycles. A wavelet transformation of a series of atmospheric precipitation reveals the relationship between precipitation and solar oscillations. Even and odd precipitation cycles are highlighted, in line with Hal’s law of magnetic polarity. Positive precipitation anomalies have been found to be consistent with the maximums of odd-numbered solar cycles and the minimums of even-numbered cycles, while negative anomalies are found to be consistent with the minimums of odd-numbered and maximums of even-numbered cycles. Highlighting cyclic components can be useful in studying changes in humidity due to climate perturbations. The obtained results can be used to make climate and hydrological forecasts for the central region of Yakutia.

Analyis of periodical variability of insolation and soil temperature in the Crimea

According to the 22-year-old series of climatology NASA Surface meteorology and Solar Energy, the results of the analysis of the temporal series of local changes in insolation and the temperature of the earth and ground air in the Crimea are carried out. A statistical analysis was carried out and a continuous time-frequency wavelet analysis revealed increased (compared to other Crimean points) insolation and heating of the earth’s surface at Kara-Dag. Using the time-and-frequency continuous wavelet analysis, six regular astronomical fluctuations, the periods of which are comparable with the periods of seasonal fluctuations, lunar and lunar-solar tidal waves, were found in the spectral structure of data on the average daily insolation incident on the horizontal surface of the earth at Kara-Dag. Periodic oscillations comparable with fluctuations in solar activity and the dynamics of rotation of the Earth-Moon system are described by sinusoidal functions, the parameters of which are determined from observations. In the data on the average daily total insolation falling on the surface of the earth at the Kara-Dag point, regular periodic fluctuations were found over an interval of periods of ~(87―402) days. The most powerful harmonic oscillations are distinguished in the interval of periods ~(231―452) days; in the time interval ~(1995―2005) years, an increasing local increase in the vibrational energy is observed. An increase in the average annual average surface temperature in the Crimea in a southeastern direction has been recorded. In individual points, deviations from the general trend are observed, which may be associated with local geological processes. The greatest warming of the earth’s surface is observed at Kara-Dag, which corresponds to increased general insolation at this point. Using the method of calculating the functions of the mutual (two-channel) power spectral density, we established mutual correlations between the time sequences of observations of local changes in insolation and changes in the length of the day, the number of sunspots, and global temperature indices.

A 1000-year record of centennial-scale cyclical vegetation change from Maar Lake Sanjiaolongwan in northeastern China

To examine possible relationships between regional changes in vegetation and climate and fluctuations in solar activity, we obtained a high-resolution 1000-year pollen record from the Sanjiaolongwan Maar Lake (SJML) in northeastern China. An age model was established using analyses of 210Pb, 137Cs and AMS 14C. The pollen assemblages indicate that during the last millennium the vegetation of the study area was temperate coniferous and deciduous broadleaved mixed forest. Although Pinus is the most abundant pollen type in the record, various lines of evidence suggest that it is not especially temperature-sensitive. However, the analysis of the changes in pollen assemblages over the past 1000 years, and a comparison with pollen records from other lakes in the region, indicate that the Quercus frequencies can be used as a relatively sensitive temperature index for the study area. Several notable cold periods, with lower Quercus frequencies, occurred at approximately 1200 AD, 1410 AD, 1580 AD, 1770 AD and 1870 AD. These centennial-scale cold periods basically correspond to major minima in solar activity, suggesting that variations in solar activity may have been an important driver of climate and vegetation change in the study area during the last millennium.

Multi-centennial-scale changes in East Asian typhoon frequency during the mid-Holocene

This study reconstructs a record of typhoon frequency over the Korean Peninsula during the mid-Holocene using mineral components and diatom assemblages in deposits of Lagoon Hyangho, located on the east coast of the peninsula. The lagoon deposits confirm the occurrence of cyclical, multi-centennial scale episodes of low salinization induced by typhoon-derived heavy rain. Although shifts in typhoon frequency broadly follow El Niño/Southern Oscillation (ENSO) conditions during the Holocene, evidence from the typhoon-induced deposits in Hyangho Lagoon suggests that the path of the polar westerly jet controls the effect of ENSO on multi-centennial-scale typhoon patterns across the mid-latitude region of East Asia. The influence of ENSO is limited when the westerly jet passes through low latitudes. Fluctuations in solar activity play a key role in regulating movement of the westerly jet. Multi-centennial scale changes in typhoon frequency in mid-latitude East Asia are, therefore, influenced by changes in solar activity and ENSO conditions.

The Origin and Development of the Central European Man-made Landscape, Habitat and Species Diversity as Affected by Climate and its Changes – a Review

The Origin and Development of the Central European Man-made Landscape, Habitat and Species Diversity as Affected by Climate and its Changes – a Review

A solar dynamo model driven by mean-field alpha and Babcock-Leighton sources: fluctuations, grand-minima-maxima, and hemispheric asymmetry in sunspot cycles

Extreme solar activity fluctuations and the occurrence of solar grand minima and maxima episodes, are well established, observed features of the solar cycle. Nevertheless, such extreme activity fluctuations and the dynamics of the solar cycle during Maunder minima-like episodes remain ill-understood. We explore the origin of such extreme solar activity fluctuations and the role of dual poloidal field sources, namely the Babcock-Leighton mechanism and the mean-field alpha effect in the dynamics of the solar cycle. We mainly concentrate on entry and recovery from grand minima episodes such as the Maunder minimum and the dynamics of the solar cycle. We use a kinematic solar dynamo model with a novel set-up in which stochastic perturbations force two distinct poloidal field alpha effects. We explore different regimes of operation of these poloidal sources with distinct operating thresholds, to identify the importance of each. The perturbations are implemented independently in both hemispheres which allows one to study the level of hemispheric coupling and hemispheric asymmetry in the emergence of sunspots. From the simulations performed we identify a few different ways in which the dynamo can enter a grand minima episode. While fluctuations in any of the $\alpha$ effects can trigger intermittency we find that the mean-field alpha effect is crucial for the recovery of the solar cycle from a grand minima episode which a Babcock-Leighton source alone, fails to achieve. Our simulations also demonstrate other cycle dynamics. We conclude that stochastic fluctuations in two interacting poloidal field sources working with distinct operating thresholds is a viable candidate for triggering episodes of extreme solar activity and that the mean-field alpha effect capable of working on weak, sub-equipartition fields is critical to the recovery of the solar cycle following an extended solar minimum.

Spatial structure of periodicity in the conifer tree radial increment in the Republic of Komi

Spectral analysis of tree ring data sets of Siberian spruce (Picea obovata) and Scots pine (Pinus sylvestris L.) was carried out to study the effects of climatic factors on the conifer tree radial growth in the territory of the Komi Republic. Analyses were performed for different natural subzones in the Komi Republic: the forest-tundra transition zone and the northern, middle, and southern taiga. The results show that several groups of periodicities can be found in the tree radial growth. One from groups of periodicities is related to internal processes in the atmosphere-ocean system; the other is related to the fluctuations in solar activity.

Can solar/geomagnetic activity restrict the occurrence of some shellfish poisoning outbreaks? The example of PSP caused by Gymnodinium catenatum at the Atlantic Portuguese coast

Cyclic outbreaks of accumulation of paralytic shellfish poisoning (PSP) toxins in mussels attributed to Gymnodinium catenatum blooms displayed several of the highest inter-annual maxima coincidental with minima of the 11-year solar sunspot number (SSN) cycle. The monthly distribution of PSP was associated with low levels of the solar radio flux, a more quantitative approach than SSN for fluctuations in solar activity. A comparison between monthly distribution of PSP and other common biotoxins (okadaic acid (OA), dinophysistoxin-2 (DTX2) and amnesic shellfish poisoning (ASP) toxins) demonstrated that only PSP was significantly associated with low levels of radio flux (p < 0.01). PSP occurrence suggests a prior decline in solar activity could be required to act as a trigger, in a similar manner to a photoperiodic signal. The seasonal frequency increased towards autumn during the study period, which might be related to the progressive atmospheric cut-off of deleterious radiation associated with the seasonal change in solar declination, and might play an additional role in seasonal signal-triggering. PSP distribution was also associated with low levels of the geomagnetic index Aa. A comparison between monthly distribution of PSP and other common biotoxins, also demonstrated that only PSP was significantly associated with low levels of the Aa index (p < 0.01). In some years of SSN minima no significant PSP-outbreaks in mussels were detected. This was attributed to a steady rise in geomagnetic activity that could disrupt the triggering signal. Global distribution patterns show that hotspots for G. catenatum blooms are regions with deficient crustal magnetic anomalies. In addition to the variable magnetic field mostly of solar origin, static fields related to magnetized rocks in the crust and upper mantle might play a role in restricting worldwide geographic distribution.

‘Adaptive cycles’ and climate fluctuations: a case study from Linear Pottery Culture in western Central Europe

By applying cycle-based resilience theory the dynamics of the Early Neolithic west-central European Linear Pottery Culture (LBK) are investigated. These are interpreted as resulting from a combination of internal socio-economic processes as well as external environmental parameters. Resilience theory is helpful in understanding periods of increased vulnerability and inherent trends to social complexity. Cycles and threshold levels also help to understand why societies experience periods of increasing fragility and subsequent decline.Results are based on the correlation of a typology and dendrochronology-based archaeological chronology for western LBK and various palaeoclimatic proxy-data. The 14C-production curve is taken as an indicator for solar activity fluctuations, and an age model for laminated sediments as an indicator for rainfall fluctuations. We currently consider this correlation as agreeably robust; however future fine-dating may result in slight shifts within the archaeological chronology.According to the applied age model, the simple farming societies of the LBK (5600–4900 cal BC) in west-central Europe were not immediately and devastatingly affected by most climate fluctuations. Yet, they might have been one destabilising component within broader processes. However, periods of decreased or irregularly spaced rainfall are contemporaneous to periods of population decline, while periods of increased rainfall may have favoured population growth. Towards the end of the 6th millennium cal BC, the final years of LBK in western Central Europe are contemporaneous to a general trend to less rainfall punctuated by short-term increases in precipitation. During this climatically highly volatile period LBK reaches its highest population rates and at the same time experiences a period of warfare. Thereafter population rates decline and LBK gradually vanishes from the archaeological record, being replaced by Middle Neolithic societies.

Solar Activity and Meteorological Fluctuations in West Africa: Temperatures and Pluviometry in Burkina Faso, 1970-2012

In this paper we investigate the fluctuations of solar activity and their links with climatic parameters in West Africa. We achieve our research by investigating several data plotted using averages. Mean to our results we can assume that active solar is associated with weak incident cosmic ray consequently with low cloudiness which brings warming. Likewise, quiet solar is associated with important cloud cover and consequently brings important precipitations and chills terrestrial atmosphere. This implies the necessity to deal with space phenomenon by considering the severe interconnection between solar activity indices for interplanetary and earth environment weather forecasting.

Examining a solar‐climate link in diurnal temperature ranges

A recent study has suggested a link between the surface level diurnal temperature range (DTR) and variations in the cosmic ray (CR) flux. As the DTR is an effective proxy for cloud cover, this result supports the notion that widespread cloud changes may be induced by the CR flux. If confirmed, this would have significant implications for our understanding of natural climate forcings. Here, we perform a detailed investigation of the relationships between DTR and solar activity (total solar irradiance and the CR flux) from more than 60 years of NCEP/NCAR reanalysis data and observations from meteorological station data. We find no statistically significant evidence to suggest that the DTR is connected to either long‐term solar periodicities (11 or 1.68‐year) or short‐term (daily timescale) fluctuations in solar activity, and we attribute previous reports on the contrary to an incorrect estimation of the statistical significance of the data. If a CR–DTR relationship exists, based on the estimated noise in DTR composites during Forbush decrease (FD) events, the DTR response would need to be larger than 0.03°C per 1% increase in the CR flux to be reliably detected. Compared with a much smaller rough estimate of −0.005°C per 1% increase in the CR flux expected if previous claims that FD events cause reductions in the cloud cover are valid, we conclude it is not possible to detect a solar related responses in station‐based or reanalysis‐based DTR data sets related to a hypothesized CR–cloud link, as potential signals would be drowned in noise.

Effect of global factors on karst formation in Nizhegorodsky oblast

In studies of the dynamics of the activation of karst and suffosion processes in the karst-hazardous districts of Nizhegorodsky oblast, temporal-spectral and correlation analyses are carried out on multiyear time series data on the number of sinkholes in the town of Dzerzhinsk, fluctuations in the water level in the Oka River, fluctuations in solar activity, and variations in the speed of the Earth’s rotation. It is shown that the dynamics of the karst and suffosion processes is related to variations in the regional fluid dynamics, which are controlled, in turn, by fluctuations in solar activity and in the speed of the Earth’s rotation.

Peatland records of solar activity

Rainwater-fed Holocene raised bog deposits in temperate climate zones are valuable archives of solar activity fluctuations and related climate changes.