Extraterrestrial Factors Research Articles

Ultraviolet Radiation Quasi-Periodicities and Their Possible Link with the Cosmic Ray and Solar Interplanetary Data

In this study, solar ultraviolet (UV) radiation data collected in Riyadh, Saudi Arabia, between 2015 and 2022 were analyzed to explore quasi-periodicities in the UV time series. The power spectrum density analysis revealed several local peaks that exceeded the 95% confidence interval. These peaks included periodicities of 483–490 days, 272 days, 157−162 days, 103−110 days, 64–72 days, 27 days, and 13 days. To investigate the potential influence of space weather parameters on UV radiation, data on cosmic rays, solar radio flux at 10.7 cm (F10.7 cm), the Kp index, and solar wind speed for the same time period were examined. The aim was to identify periodicities in these variables that aligned with those found in the UV radiation data. The analysis reveals that several periodicities observed in the UV radiation spectrum are also present in the spectra of the considered parameters. Prominent periodicities include a 270-day cycle in UV radiation and cosmic rays, as well as periodicities of 72 days, 27 days, and 13 days in all considered variables. Furthermore, 110-day peaks are observed in spectrum of the UV radiation, the Kp index, solar radio flux F10.7, and solar wind speed. Notably, consistent peaks at 157-day periodicity are identified in the UV spectrum, also present in the spectra of all the considered variables (cosmic rays ∼162 days, Kp index ∼162 days, solar radio flux ∼156 days, and solar wind speed ∼163 days). The identification of common periodicities between UV radiation and space weather parameters in this study provides compelling evidence of a potential direct or indirect influence of solar variations on UV radiation. This finding significantly enhances our understanding of the impact of extraterrestrial factors, particularly solar activity, on the Earth’s environment.

Effects of wind speed and tropospheric height on solar power generation: Energy exploration above ground level

Terrestrial and extraterrestrial factors hinder the exploitation of solar power using a ground platform. This paper is concerned with the generation of solar power above ground level. This paper employs modeling and simulations coupled with experimentation to establish a functional relationship between the percentage of solar power gain, tropospheric height, and wind speed. The finite difference method based on the Cranks–Nicolson scheme was used to realize the model solution. The wind flow equation established a linear relationship between tropospheric height and wind speed, between tropospheric height and the percentage of solar power gain. It is evident that an infinitesimal percentage of solar power gain (≈2.5%) corresponded to 1000 m above ground level; the tropospheric height of 8100 m recorded 23% of solar power gain. Furthermore, wind speeds of 0 to 33 ms −1/distance (1000 m) correspond to ground level and tropospheric height of about 8100 m respectively. However, there is a prospect of achieving more percentage of solar power gain by applying high-altitude platforms. The results obtained apply to other study areas having elevations close to 1100 m, it serves as a guide in the estimation of the percentage of solar power gain by the virtue of tropospheric height and wind speed.

Long-Term Rainfall Trends in South West Asia—Saudi Arabia

In this study, rainfall data from 19 stations in Saudi Arabia (SA) for the period 1985-2019 was utilized to investigate interannual, monthly, and seasonal rainfall variations and trends. The magnitudes of these trends were characterized and tested using Mann-Kendall (MK) rank statistics at different significance levels. During this study period, the mean rainfall in SA showed a slight and significant decreasing trend by about 2 mm/35 years. Investigation of seasonal trends of rainfall revealed that Winter and Spring rainfall decreased significantly by 2.7 mm/35 years and 5.4 mm/35 years respectively. Three months showed very slight significant decreasing trends of rainfall. These were the months of February, March and April. Mann-Kendall analyses were carried out to investigate the annual trends of rainfall during three sub-periods, i.e., 1985-1996, 1997-2008, and 2009-2019. The results revealed that while rainfall increased by 5.3 mm/12 years and 7.8 mm/11 years for the first and the third periods respectively, it decreased by about 11 mm/12 years during the second period. While trends of rainfall in Saudi Arabia are affected by large scale circulations and local factors, the effect of extraterrestrial factors, such as solar activity and its consequent effects on the climate may, additionally, play a potential role in affecting the pattern of rainfall in Saudi Arabia.

From Cultured Vascular Cells to Vessels: The Cellular and Molecular Basis of Vascular Dysfunction in Space.

Life evolved on this planet under the pull of gravity, shielded from radiation by the magnetosphere and shaped by circadian rhythms due to Earth’s rotation on its axis. Once living beings leave such a protective environment, adaptive responses are activated to grant survival. In view of long manned mission out of Earth’s orbit, it is relevant to understand how humans adapt to space and if the responses activated might reveal detrimental in the long run. Here we review present knowledge about the effects on the vessels of various extraterrestrial factors on humans as well as in vivo and in vitro experimental models. It emerges that the vasculature activates complex adaptive responses finalized to supply oxygen and nutrients to all the tissues and to remove metabolic waste and carbon dioxide. Most studies point to oxidative stress and mitochondrial dysfunction as mediators of vascular alterations in space. Unraveling the cellular and molecular mechanisms involved in these adaptive processes might offer hints to design proper and personalized countermeasures to predict a safe future in space.

Seasonal trends of the cosmic ray intensity observed by 16 neutron monitors for 1964–2020

The intensity of neutrons as secondary cosmic rays has typical modulations, such as diurnal and solar cyclic variation or transient events. Jeong and Oh (2020) examined the seasonal variation using data of the Oulu neutron monitor, but the seasonal variations and their origins were difficult to determine. In this study, the daily data of 16 neutron monitors from 1964 to 2020 were used to examine the seasonal variation and its origin. The solar cyclic variations were eliminated by normalizing to the yearly mean or median and selecting the representative value of each day from the mean or median for 57 years. Sixteen neutron monitors showed a clear seasonal trend for four ways of data transformation based on the Cox and Stuart trend test. Furthermore, the seasonal trend remained steadfast, excluding the outliers of each year to remove the variations by sporadic effects. The seasonal trend showed the maximum in January and the minimum in June. Out of 16 neutron monitors, an attempt was made to find the groups with a homogeneous seasonal trend. The statistical clustering method using the K-means idea provides two types of groups: Thule-type and Newark-type. The difference between the two groups showed the different recovery period from the minimum value and the combination of semiannual wave. This difference may result from a combination of terrestrial and extraterrestrial effects depending on the neutron monitor’s latitude and altitude. We considered the various origins of the seasonal trends including terrestrial and extraterrestrial factors. The seasonal trends may originate from the combination of various sources, including terrestrial and extraterrestrial factors rather than from one independent factor.

Determination of Radioactivity Levels in Different Mushroom Species from Turkey

Radioactivity in the environment occur due to natural, terrestrial, extra-terrestrial factors or caused by the human activity. Food stuffs that grown in the soil which containing radioactive elements may get deposited or absorbed in the foods. Wild growing mushrooms can accumulate many types of toxicological, nutritional and radioactive elements. So, mushrooms are considered as good bio-indicators to determine the environmental pollution caused by radiations. Knowing the levels of radioactivity in the food stuffs is of great importance for the protection of human health. In this study, the active concentrations of the naturally occurring 238U, 232Th, 40K nuclides and artificially occurring 137Cs nuclide were determined and annual effective doses and excess lifetime cancer risk values were calculated in mushrooms commonly consumed by the Turkish people. 15 types of mushroom samples were collected from different locations of Turkey. The results show that the activity concentrations of 238U, 232Th, 40K and 137Cs varied from 9.2±1.6 to 75.4±8.8 Bq kg-1, 10.9±1.6 to 76.3±8.9 Bq kg-1, 925.9±29.0 to 3848.0±73.2 Bq kg-1 and 6.1±1.1 to 2824.8±79.8 Bq kg-1, respectively. The mean total annual effective dose was found to be 11.5 μSv y-1. 40K radionuclide was the highest contributor to the total annual effective dose (5.35 μSv y-1). According to these values obtained, the mean excess lifetime cancer risk (ELCR) of mushrooms was determined as 4.6 x10-5 %.

Terrestrial Seismic Activity and Neutrons from the Surface of the Earth Associated with Lunar and Solar Tides

drastic increase in the flux of thermal neutrons of secondary cosmic radiation coming from the Earth was observed in the Pamir Mountains during the solar eclipse of July 22, 1990. In the following years, such phenomena were observed on each new moon and each full moon, when lunar and solar tides combine to produce an exceptionally high resultant tide. Tidal forces may serve as a trigger for the release of the deepearth seismic energy in a certain region. This directed our attention to the search for a temporal correlation between earthquakes and new and full moons, which may help identify a new type of seismic activity precursor. Such a correlation was found in the circum-Pacific belt and the adjacent regions at latitudes above 40° N and 10° S. The results of daytime measurements of the thermal neutron flux from the surface of the Earth in the Western Pamirs (Moskvin Glade, 4200 m above sea level) on August 1–14, 1994, are reported in the present study. Since these days were quiet in terms of weather and heliophysical and geophysical activity, the intensity of neutrons of secondary cosmic radiation was expected to remain almost constant. However, twofold (or even larger) intraday variations of the neutron count rate were observed on August 1–14, 1994. These quiet measurement conditions rule out the possibility that these bursts were associated with certain known extraterrestrial factors. It has been demonstrated that the observed neutron-intensity peaks were produced by lunar and solar tides. These results confirm that tidal forces play a prominent part in the generation of neutron fluxes from the surface of the Earth. The Astronomical Yearbook for 1994 published by the Russian Academy of Sciences was used in the present study.

Tectonic aspects of Precambrian metallogeny of gold and uranium

A cause-and-effect relation is established between historical metallogeny of gold and uranium and extraterrestrial factors (impact events, evolution of the distance between Earth and Moon, rotation geodynamics), which significantly affected the Early Precambrian tectonic evolution of our planet. It is shown by the example of the complex Witwatersrand deposit that the Precambrian polygenetic Au and U deposits of the quartz–pebble type were formed within a near-equatorial epi-Archean supercontinent and were related to extraterrestrial factors under a rotation regime of the plume vertical tectonics. The beginning of breakup of the epi-Archean supercontinent in the Paleo- and Mesoproterozoic (2.0 ± 0.3 Ga) was related to the abrupt decrease in the velocity of the Earth’s axial rotation followed by the dominant regime of subhorizontal plate tectonics and formation of rich U deposits of the nonconformity type (which are structurally related to the horizontal inertial detachments at the contacts of the consolidated crust) and Meso- and Neoproterozoic sedimentary complexes.

ESTIMATED GEODYNAMIC IMPACT FROM ZONES OF COLLISION AND SUBDUCTION ON THE SEISMOTECTONIC REGIME IN THE BAIKAL RIFT

The paper briefly overviews the evolution of ideas concerning causes and mechanisms related to the origin of the Baikal rift zone (BRZ) in the centre of the Eurasian plate, discusses parameters of the recent seismogeodynamic impact on the seismotectonic regime in BRZ due to the Western Pacific subduction and the Indo-Eurasian collision, and attempts at estimating their contributions to the modern geodynamics of rifting processes in Pribaikalie. Seismic migration processes and specific density patterns of the released seismic energy are analyzed for two selected profiles between BRZ and the regions of collision and subduction. A statistical method is proposed to calculate seismic migration from space-time diagrams, and equations are developed to show a decrease in specific density of seismic energy released in the lithosphere at a distance from the interplate boundaries towards the Baikal rift. The modern geodynamic impact on the seismotectonic regime in BRZ due to the Indo-Eurasian collision is reflected in moderate horizontal compression of the lithosphere, mainly in the southwestern BRZ and partly in the central BRZ. In the transition area in this profile, the specific density of released seismic energy is about 1.72×1010 J/km2. The geodynamic impact on the seismotectonic regime in BRZ from the subduction zone (from the Nankai trough) is shown by a significantly lower specific density of released seismic energy, 1.02×1010 J/km2. In the lithosphere of the northeastern BRZ, a weaker geodynamic influence is mainly manifested by responses to strong seismic events and earthquake focal mechanisms with a clear strike-slip component in the Chara and Tokka basins located in the Aldan shield of the Siberian platform. We discuss a possible mechanism that drives the propagation of the geodynamic impact on BRZ from the interplate contact areas. In our opinion, the geodynamic influence propagates intermittently in the lithospheric plates due to motions of slow-deformation-wave fronts, which are reflected in the diagrams as seismic activity clusters. The longrange propagation of slow waves is realized through triggering of active faults in the lithosphere. Such faults interacting with slow wave deformations may be manifested as excited sources of dissipation of seismic oscillations resulting from a spontaneous release of the energy accumulated in the Earth interior. This mechanism of endogenous energy supply may explain the observed propagation of recordable slow elastoplastic deformations for many thousands of kilometres. Today, when the new materials are available to show more ancient ages of the early elements of BRZ, and it is established that the tectonic energy is reduced with distance from the interplate boundaries, there is no support for the hypothesis based on the role of the Indo-Eurasian collision in the formation of BRZ. A recordable seismotectonic impact on the seismic regime in BRZ can occasionally occur after a major seismic activity in the regions of collision and subduction. This phenomenon may be used as a criterion for developing medium-term earthquake predictions, taking into account a delay in response. Short-term cycles observed in the seismic regime of BRZ and its adjacent areas, as well as in the seismic migration processes are considered as a basis for making a conclusion that seismotectonic processes associated with interactions between the plates, as well as the seismic migration processes may be impacted by a potential modulating influence of cosmogenic factors. Such extraterrestrial factors include short-term variations in the Earth’s rotation and orbiting modes, as well as in gravitational interactions between the Earth, Sun and Moon. It is unlikely that the shortterm cycles may result from the slow endogenous processes of thermal convection in the Earth.

Extraterrestrial factors and their role in the Earth’s tectonic evolution in the Early Precambrian

The paper is focused on the fundamental problem of influence of extraterrestrial factors on the Earth’s geologic and tectonic evolution. Extraterrestrial factors played a decisive role in the Earth’s genesis, the formation of the first Hadean continental crust, and the beginning of the Archean era. Their significant influence persisted in the later epochs: Even in the Phanerozoic, extraterrestrial factors might have had a considerable influence on the environment. The sialic cores of protocontinental crust (4.4-3.9 Ga) with first-generation greenstone zones (3.8-3.2 Ga) and the global system of granite-greenstone belts (3.1-2.7 Ga) formed in the rotation-plume regime, mainly in the subequatorial hot belt. The formation of these global structures was, to a large extent, influenced by asteroid impacts, which caused the impact-triggered genesis of mantle plumes. Dramatic changes in the subsequent geologic history began at 2.7-2.0 Ga; at 2.0 Ga they terminated with the Moon’s transition to an orbit similar to the present-day one (50 ± 3 Earth’s radii), accompanied by the abrupt slowdown of the Earth’s axial rotation, the termination of formation of the layer D", and the start of recent plate tectonics, which is accompanied by the plume tectonics.

Abiotic causes of the great mass extinction of marine biota at the Triassic-Jurassic boundary

In the interval of the Triassic-Jurassic boundary up to 80% of marine species became extinct. The main hypotheses on the causes of this mass extinction are reviewed. The extinction was triggered by a powerful eruption of basalts in the Central Atlantic Magmatic Province. In addition, several impact craters have been found. Extraterrestrial factors resulted in two main sequences of events: terrestrial, leading to strong volcanism, and extraterrestrial (impact events). They produced similar effects: emissions of harmful chemical compounds and aerosols. Consequences included the greenhouse effect, darkening of the atmosphere (which prevented photosynthesis), stagnation of the oceans, and anoxia. Biological productivity decreased; food chains collapsed. As a result, all vital processes were disturbed, and a large portion of the biota went extinct.

Long-term prediction on Baltic fish stocks based on periodicity of solar activity

The methods presently in wide use for the assessment of marine ecosystems and fish stocks cannot provide the high-quality long-term prognoses urgently needed for improved management of marine ecosystems and their fishery resources. A novel method of forecasting the long-term qualitative com- position of ecosystem and fish stocks in the Baltic Sea based on the periodicity and succession of the processes: extraterrestrial factors ? climate chan- ges ? regime forming factors (chiefly salinity and temperature) ? ecosystems ? fish stocks was used in 1989 to predict the approximate year class abun- dances of cod (Gadus morhua callarias), sprat (Sprattus sprattus balticus), sea herring and gulf herring (Clupea harengus membras) in the Baltic Sea for the years 1989-2008. A comparison with actual development up to 2008 show that this prog- nosis was confirmed to a considerable extent. The method based on periodical fluctuations of freshwater input and the thermal regime is described. It predicts a new regime shift in the 2020s to a higher salinity and more acceptable conditions for the organisms of marine origin.

Global geodynamic evolution of the Earth and global geodynamic models

The paper is a synthesis of models for basic geodynamic processes (spreading, subduction transient into collision, mantle plumes) in relation with the Earth's evolution and regularly changing geodynamic parameters. The main trends and milestones of this evolution record irreversible cooling of the Earth's interior, oxidation of the surface, and periodic changes in geodynamic processes. The periodicity consists of cycles of three characteristic sizes, namely 700–800 Myr global cycles, 120, 90, and 30 Myr smaller cycles, and short-period millennial to decadal oscillations controlled by changing Earth's orbital parameters and, possibly, also by other extraterrestrial factors. Major events and estimates of mantle and surface temperatures, heat flow, viscosity, and the respective regimes of convection and plume magmatism have been reported for the largest periods of the Earth's history: Hadean (4.6–3.9 Ga), Early Archean (3.9–3.3 Ga), Late Archean (3.3–2.6 Ga), Early Proterozoic (2.6–1.9 Ga), Middle Proterozoic (1.9–1.1 Ga), Neoproterozoic (1.1–0.6 Ga), and Phanerozoic with two substages of 0.6–0.3 and 0.3–0 Ga. Current geodynamics is discussed with reference to models of spreading, subduction, and plume activity. Spreading is considered in terms of double-layered mantle convection, with focus on processes in the vicinity of mid-ocean ridges. The problem of mafic melt migration through the upper mantle beneath spreading ridges is treated qualitatively. Main emphasis is placed on models of melting, comparison of experimental and observed melt compositions, and their variations in periods of magmatic activity (about 100 kyr long) and quiescence. The extent and ways of interaction of fluids and melts rising from subduction zones with the ambient mantle remain the most controversial. Plume magmatism is described with a “gas torch” model of thermochemical plumes generated at the core-mantle boundary due to local chemical doping with volatiles (H 2, CH 2, KH, etc.) which are released from the metallic outer core, become oxidized in the lower mantle, and decrease the melting point of the latter. The concluding section concerns periodicities in endogenous processes and their surface consequences, including the related biospheric evolution.

Platinum element group variations at the Permo–Triassic boundary in Kashmir and British Columbia and their significance

The end Permian marks the greatest extinction in the geological record, but there is no consensus on whether it was caused by terrestrial or extraterrestrial factors. Platinum group elements (PGE) can readily separate extraterrestrial from terrestrial sources and the few studies so far (from China and Europe) indicate terrestrial sources for the PGE. We report here detailed PGE analyses of two expanded sections from the late Permian northern and southern hemispheres that allow separate events to be distinguished and confirm a terrestrial source for the PGE. These sources are either contemporaneous seawater or older basaltic volcanics associated with the sections and the PGE were precipitated by a possible combination of development of anoxia in the oceans and post-depositional redistribution. The PGE content in sections at the Permo–Triassic boundary is the result of geochemical and lithological control on metal precipitation that is found in many other black shales throughout geological time.

Late permian changes in conditions of the atmosphere and environments caused by halogenated gases

There are periods in the Earth’s history when environmental conditions and the climate sharply changed. Some of such changes were accompanied by mass extinction of living organisms and a decrease in the species diversity. At present, there exist numerous hypotheses and conflicting scenarios of terrestrial and extraterrestrial events which led to such consequences. In particular, the most striking such episode belonging to the Late Permian is related to eruption of volcanoes in Siberia, the impact of a large asteroid, and climatic fluctuations caused by a decrease in the ozone concentration in the atmosphere (see for instance, [1]). By the ratio of isotopes in sedimentary rocks, there was revealed a degradation of vegetation in that period, which was accompanied by an appreciable decrease in productivity of photosynthesis [2]. The photosynthesis reduction resulted in a decrease in O 2 and an increase in CO 2 concentrations in the atmosphere and oceans. Volcanic emission of CO 2 in Siberia in the Late Permian also contributed to a general increase in the CO 2 concentration on the Earth. The change in the radiation budget, the warmed-up climate of the Earth, and aridization of some regions on the planet could cause mass extinction of living organisms [1]. The mass extinction of living organisms on the Earth at the boundary between the Permian and Triassic is known to have lasted over a million years (within the interval of 252.3 ± 0.3‐251.4 ± 0.3 Ma ago), i.e., in a very short period of time in terms of geology. Died out during this period were 90% of sea species, 60% of reptile and amphibian families, 30% of insect varieties, and most terrestrial plants [3]. The gradual and continuous changes in the species diversity of living organisms indicate that the mass extinction was caused by a gradual effect rather than a geologically instantaneous event spanning over several years or centuries. This suggests that such global changes began due to terrestrial causes, and later other, probably, extraterrestrial factors came into play. This work discusses a new possible cause of changes in the state of the Earth’s system and mass extinction of living organisms at the boundary between the Permian and Triassic, which was related to an increased emission of volatile phytotoxicological halogenated hydrocarbons (HHCs) from hypersalt lakes and seas. The possibility for HHC to form actively in water and bottom sediments of such water bodies was revealed in recent years in the course of studying aridization processes during climatic warming [4, 5].

Network growth approach to macroevolution

We propose a novel network growth model coupled with the competition interaction to simulate macroevolution. Our work shows that competition plays an important role in macroevolution and it is more rational to describe the interaction between species by network structures. Our model presents a complete picture of the development of phyla and the splitting process. It is found that periodic mass extinction occurred in our networks without any extraterrestrial factors and the lifetime distribution of species is very close to the fossil record. We also perturb networks with two scenarios of mass extinctions on different hierarchic levels in order to study their recovery.

Dynamic phase microscopy, a new method to detect viable and killed spores and to estimate the heterogeneity of spore populations

One of the challenging tasks in monitoring studies is to estimate heterogeneity of microbial populations by the physiological state and potential viability of individual cells, especially with regard of their ability to withstand various environmental assaults. Previously, we described some approaches based on electron microscopy methods to discriminate vegetative, dormant, and dead cells in both aged microbial cultures and environmental samples, including permafrost. We propose to extend the arsenal of microscopy methods for monitoring studies by a new non-invasive and informative method – dynamic phase microscopy (DPM). The substantial advantage of DPM is that it gives quantitative (digitized) data of undestroyed (living) microscopic objects, exemplified in our work by Bacillus licheniformis spores. Using DPM made it possible to record interference images of objects (spores) and to produce picture of their “phase thickness” (PT) that is the optical path difference in nm. Thus, it was demonstrated the remarkable difference in the PT of spores at different physiological states: dormant, germinating, and heat-killed spores had PT values of 80, 40–50, and 20 nm, respectively. The other found criterion to distinguish between spores was the PT fluctuations. In contrast to dormant and killed spores, the PT of germinating spores oscillated with amplitude of up to 7 nm, with typical frequencies of 1.3 and 3.4 Hz. A combination of the recorded PT values and PT fluctuations gave a key to detect viable and dead cells. Under the conditions that did not support germination (the lack of nutrients), we were able to follow the response of a single dormant spore and a spore population to heating from 25 °C to 70 °C. Thus, a very small temperature change (from 40 °C to 42 °C) under conditions non-favorable for germination, caused a drastic decrease in the spores’ PT; the second drop in the PT values was observed during heating from 60 °C to 70 °C. These changes were reversible: after cessation of heating, PT values became similar to dormant spores. So, DPM allowed us to track the first, reversible stage of activation, when a spore maintains the attributes of the dormant state. Under the conditions that favor germination (in the presence of nutrients), irreversible changes in the PT and spore diameter, d, were detectable in a single germinating spore and spore population. In addition, DPM allowed an easy estimation of the heterogeneity of spore populations. It is a great advantage of DPM that it makes possible to reveal the ability of spores to respond to various stimuli with or without further germination and outgrowth – the salient feature of a living cell. DPM may have a high potential in general microbiology and astrobiology, enabling to: (1) estimate the heterogeneity of spore populations either under standard conditions and subjected to solar radiation and simulated extraterrestrial factors; (2) to track a response of spores to changing conditions at the early germination stage, even if they do not enter further outgrowth; (3) to develop some approaches for monitoring studies and appraisal of the physiological state of dormant cells in situ, in samples of dry soils, permafrost, etc. regarded as models for searching life beyond the Earth.

Development of marine biota in the Paleozoic in response to abiotic factors

An analysis of the biota development in response to the changing abiotic factors shows that long relatively stable periods of transgression, high-energy hydrodynamics, and diverse ecological niches are favorable for a growth of biodiversity and the abundance of organisms. Biota reduction is determined by sharp environmental changes, particularly by multiple alteration of opposite development trends (transgression-regression, warming-cooling, and others). In addition, events harmful for the development of organisms such as global anoxia in the oceans, powerful eruptions of trap basalts and volcanism, and collision of the earth with extraterrestrial bodies negatively influence the biota evolution. The impact of different factors is particularly notable during biotic crises. The abiotic factors influencing the biota development are determined by three fundamental causes: terrestrial, orbital, and extraterrestrial. Frequently, these causes and relevant factors were synchronous or almost synchronous in terms of geological time. Inasmuch as there is no cause-effect relationship between them, we can assume that large-scale environmental changes are determined by general extraterrestrial factors originating beyond the solar system.

Paleoclimatic potential of the northernmost juniper trees in Europe

In late summer 2004 stem discs were collected from about 40 juniper trees ( Juniperus Siberica Burgsd) growing at the remote central part of Kola Peninsula behind the polar circle at the northern timberline. Up to now these juniper trees are oldest ones found at Kola Peninsula. Data processing was difficult due to extremely small tree rings as well as the occurrence of missing and false rings. However, finally it was possible to build up a 676-year long chronology and retrieve information on the past climatic variations at Kola Peninsula that could partly be linked to extraterrestrial factors such as changes in solar activity and galactic cosmic ray activity. It was obtained that: (1) There is a rather good agreement between long-term climatic variation in Europe and at Kola Peninsula. (2) The minima of solar activity Sporer (1416–1534 AD), Maunder (1645–1715 AD) and Dalton (1801–1816 AD) were accompanied by temperature decreases. Cooling during the end of the Wolf minimum (until 1350) is reflected in the juniper tree-ring series from Kola Peninsula whereas it is not reflected in the European temperature reconstructions. (3) Some recent decreases in solar activity around 1900 and 1960 are linked to phases of reduced growth in juniper. (4) The juniper chronologies from Kola Peninsula do not indicate a temperature rise at the end of the XX century. (5) MTM spectral and wavelet analysis of juniper tree-ring records showed: (a) more pronounced 22- and 80–100-year periodicities; (b) the main cycle of solar activity, the 11-year Schwabe cycle, was not present; (c) 20–22-year periodicity was not significant throughout the entire ca.700-year period, but during certain time intervals: 1328–1550, 1710–1800, 1985 to present.

Global heat budget, plate tectonics and climatic change

For the past 2000 Ma, the temperature of the Earth's surface has fluctuated around a mean similar to that of today, although individual locations have undergone long‐term changes of ∼30°C at different times in different places. Water bodies absorb at least five times as much solar radiation as land surfaces, and ocean currents transport the excess heat absorbed in the tropics towards the poles. Changes in the distribution of land and sea due to plate tectonics explain the major temperature fluctuations (>25°C) around the globe in the last 350 Ma, and are first‐order controls. Large‐scale changes in ocean currents and thermohaline circulations are probably second‐order controls (15–25°C). The Milankovitch orbital cycles are third‐order controls producing variations in air temperature of the order of 10°C, while massive volcanic eruptions and changes in carbon dioxide are amongst the fourth‐order controls producing minor perturbations (<5°C). The major climatic fluctuations are continuous but regional in effect and not global. Extraterrestrial factors may not cause major changes in climate when viewed from a geological perspective.