Secular Cycles Research Articles

A Hydrochemical Method for Identifying Orbital Imprints of Dust in Paleofluvial Sequences

AbstractMineral dust plays an important role in Earth's climate system, yet it is difficult to identify dust imprints in paleofluvial sediments, especially on orbital timescales. Here, we present high‐resolution authigenic carbonate Ca–Mg–Sr compositions in a fluvial sequence under the transport pathway of Asian dust. The Mg/Ca, Sr/Ca, and Mg/Sr ratios exhibit distinct transitions in both secular trends and orbital cycles at ∼8 Ma. Before ∼8 Ma, given similar Mg and Sr partitioning behaviors during carbonate formation, hydroclimate changes yielded strong orbital signals in the Sr/Ca and Mg/Ca ratios but no detectable signals in the Mg/Sr ratios. After ∼8 Ma, given the strengthened input of Mg‐rich dust during cold‒dry periods, the Mg/Sr and Mg/Ca ratios clearly exhibited orbital signals, but the Sr/Ca ratio did not. Such transitions in carbonate composition corroborate the dust‐induced changes in fluvial hydrochemistry, offering an innovative methodology for detecting orbital dust cycles in paleofluvial systems.

The Demographic-Wealth model for cliodynamics.

Cliodynamics is a still a relatively new research area with the purpose of investigating and modelling historical processes. One of its first important mathematical models was proposed by Turchin and called "Demographic-Fiscal Model" (DFM). This DFM was one of the first and is one of a few models that link population with state dynamics. In this work, we propose a possible alternative to the classical Turchin DFM, which contributes to further model development and comparison essential for the field of cliodynamics. Our "Demographic-Wealth Model" (DWM) aims to also model link between population and state dynamics but makes different modelling assumptions, particularly about the type of possible taxation. As an important contribution, we employ tools from nonlinear dynamics, e.g., existence theory for periodic orbits as well as analytical and numerical bifurcation analysis, to analyze the DWM. We believe that these tools can also be helpful for many other current and future models in cliodynamics. One particular focus of our analysis is the occurrence of Hopf bifurcations. Therefore, a detailed analysis is developed regarding equilibria and their possible bifurcations. Especially noticeable is the behavior of the so-called coexistence point. While changing different parameters, a variety of Hopf bifurcations occur. In addition, it is indicated, what role Hopf bifurcations may play in the interplay between population and state dynamics. There are critical values of different parameters that yield periodic behavior and limit cycles when exceeded, similar to the "paradox of enrichment" known in ecology. This means that the DWM provides one possible avenue setup to explain in a simple format the existence of secular cycles, which have been observed in historical data. In summary, our model aims to balance simplicity, linking to the underlying processes and the goal to represent secular cycles.

Long-run evolution of income inequality in the Nordic countries

ABSTRACT This paper surveys Nordic historic studies on the distribution of income to highlight similarities and differences between Denmark, Finland, Norway, and Sweden in the evolution of income concentration and income inequality over more than 140 years. Our descriptive analysis allows for a decomposition where we identify the contribution of the income share of the richest 1 per cent and the distribution of income among the other 99 per cent to overall inequality as measured by the Gini coefficient. The results show that the evolution of income concentration and inequality can be characterised by episodes rather than by secular cycles, which means that the evolution can neither be summarised by Kuznets’ inverse U nor by a U. The evidence on the role played by the share of the top 1 per cent for overall income inequality shows to be mixed and to vary across time and countries.

Possible Influence of Solar Cyclicity on Extratropical Cyclone Trajectories in the North Atlantic

In this work, we study long-term changes in the main directions of movement (storm tracks) of extratropical cyclones in the North Atlantic for the period 1873–2021, based on the data of the MSLP (Mean Sea Level Pressure) archives from the Climatic Research Unit and NCEP/DOE AMIP-II reanalysis. It was found that in the cold half of the year, the mean latitudes of storm tracks undergo oscillations with the periods ~80–100, ~40–45, and ~22 years, which indicates their possible association with solar cyclicity. Cyclone trajectories were found to shift northward at the minimum of the Gleissberg secular cycle (~1900–1930) and southward at its maximum (~1940–1960). The secular variations are the most pronounced in the western part of the North Atlantic, with the peak-to-peak amplitude reaching ~3–5°, and disappear at longitudes east of Greenwich. On the bidecadal timescale, cyclone tracks were found to shift noticeably to the north in even solar cycles and weakly to the south in odd ones. The most significant northward shifts (~1–2°) were detected during the descending phase and the minimum of the solar cycle (from the second to the sixth year after the solar maximum) in the eastern part of the North Atlantic (longitudes 30–10° W). The detected oscillations of cyclone trajectories may be caused by long-term changes in the intensity of the stratospheric polar vortex associated with galactic cosmic ray variations and geomagnetic activity.

Факторы, определяющие возможную экспансию речного бобра (Castor Fiber, L.) в центральной лесостепи (на примере Курской области)

Studies of the population dynamics of commercial mammal species are necessary both for the conservation of biodiversity and for solving a number of applied issues. The ever-increasing rate of expansion of the river beaver in the central forest-steppe necessitates long-term monitoring. This is all the more relevant since official sources indicate the number of beaver within 1–2 individuals/km of watercourse, while according to our data, it is at least 10–12 individuals/km. The aim was to determine the influence of climatic and anthropogenic factors on the sharp increase in the number of European beaver in the most typical wetland systems of the rivers of the Dnepr and Don basins (Seim, Psel, Oskol, Sosna). To count the number of the river beaver, a statistical method was used, supplemented by a cartographic one, with the creation of maps using geoinformation technologies. The results obtained show that the increase in the number of beavers is due to the temporary coincidence of favorable climatic factors against the background of minimal fishing pressure. Thus, the simultaneous significance of two main hypotheses is emphasized: “cyclic-trophic” and “anthropogenic-predatory”, the influence of which on commercial mammals is considered separately. The fundamental significance for the "explosive growth" of the beaver populations of the onset of the warm-dry phase of the secular cycle is shown. Based on the data obtained, a conclusion was made about the fundamental influence of the two-factor system on the state of beaver populations in the central forest-steppe. Keywords: RIVER BEAVER, CENTRAL FOREST-STEPPE, KURSK REGION, GIS IN GEOECOLOGY

Prince’s Trident on Frescoes and Graffiti of St. Sophia of Kyiv

The article, for the first time in academic research, puts and comprehensively considers a unique phenomenon of picturing seven images stylized under the lily of the prince’s tridents of Volodymyr on the frescoes and graffiti of St. Sophia of Kyiv, which elucidates the time of the cathedral construction and its prince-builder. They are singled out as separate compositions, “inserted” in the center of large narrative scenes of the religious and secular nature. Four tridents of Volodymyr are present in four frescoes of the vestry, decorated with scenes from the cycle of the Virgin; two more are present in the fresco of the north stair tower, which is part of the secular cycle that tells about the conclusion of dynastic marriage between Prince Volodymyr and Byzantine Princess Anna. Two inverted tridents of Volodymyr, drawn by his warriors after the death of the prince, were found in the graffiti of St. Sophia. They appeared around 1017 after Yaroslav’s capture of the Kyiv throne. Volodymyr’s trident on the walls of St. Sophia is a sign of his ownership of the temple and the glorification of the prince in the eyes of contemporaries and descendants. On the wall of the St. Michael’s altar of the cathedral there is a trident of Iziaslav Yaroslavych, similar to the lilies on the frescoes of the cathedral, which in the conditions of feud marked the right of this prince to Kyiv and St. Sophia, its heart. Iziaslav’s trident appeared here during the difficult period between 1068 and 1078. The prince’s tridents did not appear in the graffiti of Sophia spontaneously, as their authors were inspired by the urgent needs of life at that time. Like the oldest dated graffiti on its walls, mosaics, and frescoes, Prince Volodymyr’s tridents confirm the inference that St. Sophia was founded by Volodymyr the Great in 1011, and during his reign the cathedral was built and decorated with mosaics and frescoes. Instead, Yaroslav’s tridents were not found on the walls of St. Sophia.

The long cycle perspective on the emerging bio age

A combined perspective of long economic cycles and very long secular cycles of production principles is proposed to anticipate the major socioeconomic implications of the emerging (bio)technological paradigm. The analysis identifies three distinct shifts that shape and promote socioeconomic development in the next five to six decades: the material shift toward renewable resources, the actual technological shift as a confluence of technological mega-trends, and the control shift toward new knowledge elites and self-regulating systems. The strongest creative and disruptive effects of the new (bio)technological leitmotif are shown to materialize at the overlap of the successive shifts. The results suggest revisiting some priority fields of the current bioeconomy and related policies and chart out key challenges beyond the strategic policy horizon of 2050.

Business cycle characteristics of Mediterranean economies: a secular trend and cycle dynamics perspective

AbstractThis study analyzes business cycle characteristics for all 20 major contemporaneous economies bordering the Mediterranean Sea based on annual real gross domestic product series for the period from 1960 to 2019. The region we investigate corresponds to the Mare Internum region of the Imperial Roman Empire during the Nerva-Antonine and early Severan dynasty, i.e., at the time of the maximum extent of the Roman Empire around 100 to 200 CE. The covered area encircles the Mediterranean, including economies now belonging to the European Union as well as acceding countries, Turkey, and the Middle East and North African economies. Using a components-deviation-cycle approach, we assess level trends and relative volatility of output. We also quantify the contribution of various factors to the business cycle variability within a region. We find cyclic commonalities and idiosyncrasies are related to ancient and colonial history and to contemporaneous trade relationships. Caliphate and Ottoman Empire membership as well as colonial rule in the twentieth century and contemporary Muslim share of population are the most promising predictors of business cycle commonalities in the region.

Long-term North–South Asymmetry of the Heliospheric Current Sheet

Abstract In this paper, we evaluate the heliospheric current sheet (HCS) north–south asymmetry using the ecliptical sector structure of the interplanetary magnetic field (IMF) reconstructed since the second half of the 19th century. During the last five solar cycles, the inferred IMF polarities fairly reproduce the observed dominance of the sectors with the polarity of the northern solar hemisphere, i.e., the prolonged southward shift of the HCS. For the presatellite era, we found that the northward shift of the HCS was more common in cycles 10, 15, and 17–19, and the southward HCS shift was more common in cycles 9, 11–14, and 16. We also analyzed the north–south asymmetry in sunspot group numbers since 1749 and found that the northern hemisphere dominated in cycles 2–3, 7–9, and 15–20, and the southern hemisphere activity was stronger in cycles 4, 9–14, and 21–24. Moreover, other solar phenomena bear similar long-term asymmetry variations. The regularity of these variations is not clear. According to the available proxies of the solar data, the dominance of the northern hemisphere is found in the ascending phase of the secular solar cycle, and the dominance of the southern hemisphere coincides with the descending phase.

Fractal dimension and area of seismicity in the Baikal Rift System: Implications for modern geodynamics

The fractal geometry and extent of seismicity in the Baikal Rift System (BRS) are estimated from data on 52,700 instrumental events of MLH ≥ 2.5 magnitudes for fifty years (1964–2013). The seismic pattern is characterized by the box-counting Hausdorff dimension D0, multifractal spectra f(α), and surface area S of seismicity at three scales: the rift system as a whole, its three zones, and six subzones. The multifractal spectra record a self-similar hierarchical structure of the BRS seismicity pattern. The space and time variations in the fractal dimension (D0) and area of seismicity (S), which are mapped and plotted as a function of time, show good correlation. The two parameters depend on three related factors: progressive increase in the amount of instrumental data (dataset size), structure of seismogenic fault network, and geodynamic activity. They increase as ever more data appear with time and acquire high local values at increasing extent and density of quakes. Moreover, the obtained D0 estimates reflect statistical self-similarity of earthquake patterns being in the range ≈ 1.45–1.55 over most of BRS, except one zone and one subzone in the rift flanks. They are the highest in the southwest and the lowest in the northeast of the rift system (D0 ≈ 1.60 ± 0.02 and D0 ≈ 1.37 ± 0.02 respectively). This dissimilarity indicates that seismogenic faulting occurs by different mechanisms: distributed failure as a result of superposed global-scale collisional compression and regional rifting in the SW flank and quasi-linear rift propagation in the NE flank. In general, D0 decreases toward the northeastern part of the BRS, where the pattern of earthquakes becomes localized along lineaments instead of being distributed over an area. The space and time variations of D0 and S revealed in the earthquake data are consistent with the location and activity pulses of rifting attractors and provide a realistic explanation of BRS geodynamics and tectonophysics. The global lithospheric compression and the regional pulse-like activity of rifting attractors control the network of seismogenic faults which, in turn, govern the fractal geometry and 2D structure of seismicity in the region. The obtained results confirm the oscillatory dynamics of the regional seismicity at a decadal period correlated with activity pulses of rifting attractors. The oscillations stand out against the background of decreasing global low-frequency secular cycle of the BRS seismicity. The BRS lithospheric geodynamics fits the model of a nonlinear oscillator with dissipation. The suggested analysis of the fractal geometry and extent of seismicity as proxies of the faulting evolution provides insights into modern geodynamics of the Baikal Rift System and its constituents.

Teratological Plot of the Ornament in the South Tower of St. Sophia of Kyiv

St. Sophia of Kyiv, built in 1011‒1018 at the turn of the reigns of Volodymyr the Great and Yaroslav the Wise, has preserved a large number of unique secular frescoes. Their customer was Volodymyr, who owns the idea of the temple, which is reflected in the mosaics and frescoes. A triumphal fresco cycle is unfolding in the two stair towers which, according to the Byzantine tradition, glorifies its customer. The frescoes tell about a dynastic marriage between Prince Volodymyr the Great and the Byzantine Princess Anna Porphyrogenitus at the turn of 987–988, which initiated the baptism of the Kyivan State. The cycle consists of narrative historical and symbolic (ornamental, zoomorphic, and teratological 4) plots. The central composition of a symbolic nature is a mysterious teratological plot of five interconnected medallions placed on the vault of the south tower. This combined plot traces the Scandinavian influences caused by Volodymyr’s princely order, which are present in the unique emblematic image of god Odin with two wolves. The decoding of the plot revealsits semantic unity both with the triumphant fresco cycle of towers, which it is a part of, and with the ideological concept of the whole temple complex as a memorial of the baptism of Rus-Ukraine, the founder and builder of which was Volodymyr the Great. The plot reveals deep sacred and at the same time ethnically colored connotations with the image of Volodymyr as a crowned prince-baptizer and a powerful military leader. This concept fits into the general marital leitmotif of the secular cycle. The frescoes of the towers present not only a completely realistic outline of the initial event of the baptism of the people (the engagement of Volodymyr and Anna) but also a corresponding symbolic and metaphorical disclosure of this theme.

Historical dynamics of the Chinese dynasties

We develop a framework for studying state division and unification, and as a case study we focus on modelling the territorial patterns in imperial China during periods of unity and upheaval. As a modelling tool we employ discrete dynamical systems and analyse two models: the logistic map and a new class of maps, which we name ren maps. The critical transitions exhibited by the models can be used to capture the process of territorial division but also unification. We outline certain limitations of uni-modal, smooth maps for our modelling purposes and propose ren maps as an alternative, which we use to reproduce the territorial dynamics over time. As a result of the modelling we arrive at a quantitative measure for asabiyyah, a notion of group solidarity, whose secular cycles match the historical record over 1800 years, from the time of the Warring States to the beginning of the Ming dynasty. Furthermore, we also derive an equation for aggregate asabiyyah which can be employed in other cases of interest.

X, Y, i Z. Teoria cyklów pokoleniowych Straussa-Howe’a w świetle wcześniejszych teorii

The aim of this paper is to familiarize Polish academic readers with hypothesis of secular cycle introduced by William Straussa and Neil Howe. In their book, The Fourth Turning: What the Cycles of History Tell Us About America’s Next Rendezvous with Destiny, authors propose to look at human generations succession as a cycle, during which some tendecnies and attitudes rise and fall. I will present the notions of the book compared to some classic theorists of generations, like, among others, Mannheim, Ortega y Gasset, Garewicz.

Eccentric Early Migration of Neptune

Abstract The dynamical structure of the Kuiper Belt can be used as a clue to the formation and evolution of the solar system, planetary systems in general, and Neptune’s early orbital history in particular. The problem is best addressed by forward modeling where different initial conditions and Neptune’s orbital evolutions are tested, and the model predictions are compared to orbits of known Kuiper Belt objects (KBOs). It has previously been established that Neptune radially migrated, by gravitationally interacting with an outer disk of planetesimals, from the original radial distance r ≲ 25 au to its current orbit at 30 au. Here we show that the migration models with a very low orbital eccentricity of Neptune (e N ≲ 0.03) do not explain KBOs with semimajor axes 50 < a < 60 au, perihelion distances q > 35 au, and inclinations i < 10°. If e N ≲ 0.03 at all times, the Kozai cycles control the implantation process and the orbits with q > 35 au end up having, due to the angular momentum’s z-component conservation, i > 10°. Better results are obtained when Neptune’s eccentricity is excited to e N ≃ 0.1 and subsequently damped by dynamical friction. The low-e and low-i orbits at 50–60 au are produced in this model when KBOs are lifted from the scattered disk by secular cycles—mainly the apsidal resonance ν 8—near various mean motion resonances. These results give support to a (mild) dynamical instability that presumably excited the orbits of giant planets during Neptune’s early migration.

“Generative” Indices of Sunspot Solar Activity: 145-Year Composite Series

Traditional indices, which we call apparent indices, describe the current state of solar activity and are very important for understanding the influence of the Sun on Earth. To study the productivity of the solar dynamo, however, we need a different index that would describe each magnetic region once – at the moment of its maximum area. We refer to such indices as generative ones. The aim of this work is to produce such a generative series improving the procedure by Nagovitsyn et al. (Geomagn. Aeron. 58, 1170, 2018). We use sunspot group data from two archives – Royal Greenwich Observatory (1875 – 1976) and Kislovodsk Mountain Astronomical Station (1955 – 2019). We produce generative indices with annual values of sunspot group areas $A$ , and counts of sunspot groups $C$ . Unified 145-year series of these indices were compiled. We study the characteristics of the indices $A$ and $C$ , and indices derived from them for two sunspot group populations – large long-living groups and small short-living groups according to Nagovitsyn and Pevtsov (Astrophys. J. 833, 94, 2016) – for the northern and southern hemispheres separately. We find a 50-year variation in several indices on the 145-year interval, and detect a similar phase variation in the north-south asymmetry taken with the opposite sign. Perhaps this indicates the existence of another secular cycle along with the Gleissberg cycle on the Sun. The obtained series of indices $A$ and $C$ can be useful for studying the long-term properties of the solar dynamo.

Solar Activity Predictability Horizons

The chaotic component in solar-activity variations, the limited amount of observational statistics, and the use of proxy data impose limitations on long-term predictions. This study uses the well-known reconstructions of total solar irradiance (TSI) from optical observations (from 1610 AD) and cosmogenic radioisotopes (from 7362 BC) to estimate the maximum Lyapunov exponent for 11-year and secular cycles. This is done with the classical algorithm described by Wolf et al. (1985). The maximum Lyapunov exponents turned out to be positive in both cases, thus confirming the presence of the chaotic component in time series. We then estimate the predictability horizon Tp with the well-known error for each reconstruction. It turned out that the predictability horizon is on average 10 ≤ Tp ≤ 22 years for 11-year cycles and on average 40 ≤ Tp ≤ 60 years for secular cycles.

Some Features of the Present-day Transition Period in Solar Activity

Various geophysical indices and their prognostic value were analyzed in (Obridko et al., 2013; Kirov et al., 2013, 2015, 2017; Georgieva et al., 2015, 2018). Two indices have been selected for the analysis (total annual Dst values, and duration of a storm). It is important to note that, unlike the other indices of solar and geophysical activity, the summary Dst index does not show violation of the Gnevyshev-Ohl rule. The analysis of annual mean Dst values reveals a clearly pronounced decrease in activity, at least since the 1980-ies. This allows us to suggest that we are at the descending branch of a secular cycle or on the threshold of a Grand Minimum. The decrease in solar activity is corroborated by the analysis of Forbush effects, solar wind speed, and intensity of the near-Earth magnetic field.

Tree-ring reconstruction of the level of endorheic lakes in the south of West Siberia

The paper presents the dendrochronological method applied in reconstructing the changes in the water level of endorheic lakes from arid areas (on the example of two large endorheic lakes Kulundinskoye and Chany). Chronologies of annual ring width of Scots pine (Pinus sylvestris L.), growing in the pine belt forests in the south of West Siberia, were used as indicators of climate change. To obtain the longest reconstructions, we used the lengthen chronologies. For analysis, specimens of living trees and old wooden houses in the Altai Krai villages (adjacent to pine-belt forests) were used. Due to the dendrohydrological analysis, we have determined the relationship between the lake level and the radial pine growth. We have revealed a one-two-year lag in the response of hydrological objects to climate fluctuations. Correlation between the tree-ring chronologies and the average annual water level of Lake Kulundinskoye occurred more often due to proximity of both geosystems, i.e. the lake and pine-belt forests. At the same time, there was the best correlation for Lake Chany and the drysteppe chronology Uglovskoye 42_LL. In the course of investigations, we have extended the series for lakes Chany and Kulundinskoye up to 1584 and 1763, respectively. Spectral analysis of the series of the water level in both lakes allowed us to identify common cycles (i.e. 25-26, 40-46 and 80-100-year ones). For Lake Kulundinskoye, the 8 and 11-year cycles turned out to be the most significant. The analysis of secular cycles of hydrological series enabled to specify the trends in water-level changes of the studied lakes in the future.

A Cultural Evolution Model for Trend Changes in the American Secular Cycle

Author(s): Alexander, Michael Allen | Abstract: Rising economic inequality in the United States has become a topic of political interest in recent years. Inequality appears to show cycles corresponding to secular cycles, suggesting the possibility of declining inequality in the future. The most recent episode of declining inequality in America is known as the Great Compression. It occurred in the middle of the 20th century. This paper uses the guided variation cultural evolution model (Boyd and Richerson 1985:95-7) to explain shifting trends in inequality in five nations. According to this analysis, the Great Compression was largely due to a shift in the business environment reflecting tax and other economic policy implemented over the 1914-45 era. The cultural evolutionary response to this environmental change was to replace “shareholder primacy” cultural variants with “stakeholder capitalism” variants which resulted in lower inequality. Half a century later, new policy, implemented in response to the great inflation following the collapse of the Bretton Woods system, changed the business environment again in ways that favored shareholder primacy cultural variants and rising inequality. The extent to which this occurred depended on the degree to which stakeholder capitalism was integrated into institutions.

Aeolian Material Migration in Transbaikalia (Asian Russia)

We revealed regional features of functioning of a large Transbaikalian aeolian morphodynamic system. Natural pre-conditions, current realities and factors of development of aeolian processes are investigated. The paper considers regularities of spatial distribution of deflation, transit, and aeolian accumulation zones. Main directions of aeolian migration of matter are determined. Pulsating nature of aeolian processes development in Holocene has been established. Identified are intrasecular cycles and Holocene dynamics of aeolian processes. We identified intrasecular (11, 27–35 years old), secular (80 year old) and Holocene (500, 2000 year old) cycles of aeolian process dynamics. The paper shows the influence of anthropogenic activity on the activation of aeolian migration of material for the historical period. It presents an overview of extreme aeolian events. Regionalization of Transbaikalia was carried out according to the degree of probable desertification of the territory due to development of aeolian processes. Areas of catastrophic manifestation of processes are highlighted. The results of long-term experimental observations of deflation and aeolian accumulation are presented. Particular attention is paid to the characteristics of the aeolian corridors. The important role of aeolian processes in the intensive material transport from Transbaikalia to the south and southeast to neighboring regions of Mongolia and China is shown.