Geophysical Institute Research Articles

Global solar radiation, assessed using a pyranometer placed on an inclined plane

The city of Zacatecas, due to its geographical location, a city with little industry, neighboring the Tropic of Cancer and a height of the order of 2,492 above sea level, has the conditions for a study of the behavior of solar radiation and its possible potential use to transform it into other types of energy. The objective of this work was to have an irradiance database in the city of Zacatecas using CMP 22 Kipp & Zonen pyranometers from Campbell scientific, in order to satisfy the needs derived from radiation-related industry activities. The pinanometers are located at the Zacatecas_04 Solarimetric Station, which is located on the UAZ Siglo XXL Campus in building 6 of the Academic Unit of Chemical Sciences of the Autonomous University of Zacatecas (Lat: 22°46'21.01''N, Long: 102°38'37.14'') in the city of Zacatecas, Zac, and is part of the Mexican Solarimetric Network promoted by the Mexican Solarimetric Service of the Institute of Geophysics of the National Autonomous University of Mexico. The data was rearranged into hourly, daily and monthly averages. The average daily irradiance was 547 ± 5 W/m².

The importance of scientific data and historical heritage of the geophysical and astronomical observatory of coimbra university for the study of geophysical sciences

AbstractThe Geophysical and Astronomical Observatory of the University of Coimbra (OGAUC) was officially created in 2013 after merging of two historical institutions: the Astronomical Observatory and the Geophysical Institute. As a result of almost 200 years of observations and research in astronomy and geophysical sciences, the OGAUC possesses a unique and valuable collection of long‐term observational and instrumental records. These data have an indispensable value in current geophysical and climatic studies, being among the most complete and significant in Portugal and the world. The OGAUC's data collections are complemented by a vast technical‐scientific production such as reports, research memoranda, articles, books, and instruments. This archive is largely not inventoried and poorly studied (particularly concerning meteorological, geomagnetic, and seismological data). This paper highlights the importance of the OGAUC's extensive data collection and discusses the difficulties and barriers related to its inventorying, preservation, and dissemination to the scientific community, policymakers, stakeholders, and the general public.

Adaptive robust unscented Kalman filter-based state-of-charge estimation for lithium-ion batteries with multi-parameter updating

State-of-charge (SOC) estimation is one of the key technologies for the development and application of battery management system (BMS). To achieve high accuracy in SOC estimation, which can adapt to any conditions, an adaptive robust unscented Kalman filter (ARUKF) based on multi-parameter update is proposed herein. First, the DP battery model is applied to replicate the dynamic behavior of lithium-ion batteries, and the model parameters are identified online by the improved forgetting factor recursive least square (IFFRLS). Then, the Institute of Geodesy and Geophysics (IGGIII) weight function is introduced into unscented Kalman filter (UKF) as the form of a robust factor to adjust the weights of observation residuals, and receding horizon based adaptive filter tuning is employed to obtain the time-varying noise covariance. Subsequently, joint estimation of battery model parameters and SOC with capacity updating is implemented which can suppress the system disturbance caused by outliers, mistuning, unknown initial value, and aging. Finally, the superior performance of accuracy and convergence is verified by cycle and aging tests. The maximum absolute error of SOC estimation under the proposed method is kept within 2%. The convergence speed of SOC estimation utilizing ARUKF is nearly 80 s faster than that of robust UKF (RUKF) and UKF under a 20% SOC initial error.

China's goal of achieving carbon neutrality before 2060: experts explain how.

‘We aim to have CO2 emissions peak before 2030 and achieve carbon neutrality before 2060,’ President Xi Jinping so declared at the General Debate of the 75th United Nations General Assembly on 22 September 2020. More than 130 countries globally have proposed their own carbon neutrality goals by 2050 or 2060. Thus, carbon neutrality is a collective effort of human societies to cope with the climate crisis. If all countries could follow their own plans and reach carbon neutrality in a few decades, we may have a chance to control global warming within 1.5 or 2oC, confining climate change to a relatively safe zone. As a developing country with a large population, high coal consumption and large manufacturing industries, can China achieve the huge task of societal transformation that will enable carbon peaking and carbon neutrality within the next four decades? How will China transform traditional power generation and manufacturing industries, as well as create new technologies for carbon capture and storage? In this panel discussion chaired by Prof. Xinhe Bao, a scientist of energy and chemistry, top experts gathered to discuss the challenges and potential solutions, outlining the coming ‘green industrial revolution’. Huiming Cheng Professor, Institute of Metal Research, Chinese Academy of Sciences; Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences Zhengtang Guo Professor, Institute of Geology and Geophysics, Chinese Academy of Sciences Yaling He Professor, School of Energy and Power Engineering, Xi’an Jiaotong University Zheng Li Professor, Institute of Climate Change and Sustainable Development, Tsinghua University Minggao Ouyang Professor, School of Vehicle and Mobility, Tsinghua University Zhengrong Shi Professor, College of Energy and Mechanical Engineering, Shanghai University of Electric Power Zaiku Xie Professor, China Petroleum and Chemical Corporation (SINOPEC) Xinhe Bao (Chair) Professor, University of Science and Technology of China, and Dalian Institute of Chemical Physics, Chinese Academy of Sciences

Presentation of so far undetermined bird remains from the Pliocene of Beremend 26 and Csarnóta 2 and 4 (Baranya county, South Hungary)

Abstract The authors have defined at the order, subfamily, family or genus level the very fragmentary and small-size bird bone material from the three Pliocene-age sites in southern Hungary (Beremend 26, Csarnóta 2 and 4), which is in the collection of the Museum of the Hungarian Institute of Geology and Geophysics. The non-catalogued bone fragments remaining from the already examined material were identified. The number of taxa identified is 26, of which one species is new to science. The new species (Pliogallus csarnotanus n. sp.) belongs to a hitherto disputed genus, which is thus recognised through the newly defined material. Of the rest of the material, only Paleocryptonix hungaricus Jánossy, 1991 and Glaucidium baranensis Kessler, 2010 have been identified to species level, the Gallinula, Porzana, Merops, Garrulus, Nucifraga finds to genus level, while the other 18 taxa have been identified only to subfamily or family level (Perdicinae, Columbidae, Alaudidae, Hirundinidae, Panuridae, Paridae, Sittidae, Certhiidae, Muscicapidae, Turdidae, Sylviidae, Motacillidae, Prunellidae, Laniidae, Sturnidae and Fringillidae), or only to order level (Charadriiformes, Coraciiformes).

Implementation of microseismic monitoring for iron ore mines

The seismic station of the Subbot Institute of Geophysics of the NAS of Ukraine (IGP), in Kriviy Rih (Ukraine) ten earthquakes were registered from 2007 to 2013. Such activity is not typical for this region. One of the reasons is mining of mineral resources in this area, leading to irreversible changes in the stress-strain state of the massif, which activate dangerous natural and man-made processes (landslides, flooding, earthquakes, mountain strikes, etc.) The collapse of the mountain massif and the exit of the funnels occurs when the limit value of the loading in the massif is reached. Limit value warning of the stress-strain state of the massif is a condition for the danger of the zone. The task of control is to prevent the stress-strain state of the massif. Any unloading of the massif is accompanied by the formation of a crack, which is characterized by a burst of amplitude and a certain frequency of oscillations. For the geographic information system of mines, it is important to highlight significant phenomena by types of energy, affiliation to the mining allotment of the mine (distance to the hypocenter) and the nature of the primary source - technical or natural. The goal of research is to define a significant phenomena for identifying the stress-strain state of the massif using the microseismic monitoring. To increase noise immunity, it is advisable to use both physical filtration methods and software selection of significant phenomena against the background of man-made noise. To form conclusions, it is necessary to form a sample, so for reliable identification of the stress - strain state of the massif it is necessary to perform statistical processing of the measurement results. The usage of microseismic control at mining enterprises will reduce the possibility of mining shocks, landslides, which will reduce material damage. This will increase the safety of mining operations and ability to prevent man-made earthquakes of magnitude more than five.

The Response of Geomagnetic Daily Variation and Ionospheric Currents to the Annular Solar Eclipse on 21 June 2020

AbstractIn this study, we examined the response of geomagnetic daily variation and ionospheric currents to the solar annular eclipse that passed through China at 10:00–17:30 LT on 21 June 2020. We utilized geomagnetic field data obtained from the Geomagnetic Network Center of China, Institute of Geophysics, China Earthquake Administration and International Real‐time Magnetic Observatory Network, which extend from middle latitudes to equatorial regions in China and surrounding areas. It is found that the eclipse obscuration reduces the intensity of geomagnetic daily variation at most stations as compared with the 5‐quiet‐day average. The response of geomagnetic daily variation to the solar eclipse depends on local time and latitude. In most shadowed areas of the eclipse, there is a reduction of northward (southward) component of the meridional magnetic daily field (ΔX) below (above) ∼30° magnetic latitudes. The solar eclipse can also induce a decrease of the zonal magnetic field variation (ΔY). Meanwhile, we observed that the solar eclipse reduces the intensity of vertical geomagnetic component (ΔZ) at the stations around the early afternoon aside the eclipse totality. In general, these geomagnetic responses imply that the solar eclipse can reduce the ionospheric solar quiet (Sq) current system. These ionospheric currents and ground geomagnetic field disturbances during the solar eclipse are also verified by a global physical model. The simulation demonstrates that the ionospheric currents in the southern hemisphere, where the solar eclipse does not cover, also have a weak response. Overall, the ionospheric current disturbance induced by the solar eclipse shows a counter‐Sq pattern.

Field Campaign Evaluation of Sensors Lufft GMX500 and MaxiMet WS100 in Peruvian Central Andes.

The research presents the inter-comparison of atmospheric variables measured by 9 automatic weather stations. This set of data was compared with the measurements of other weather stations in order to standardize the values that must be adjusted when taken to different areas. The data of a set of a total of 9 GMX500, which measures conventional meteorological variables, and 10 WS100 sensors, which measures precipitation parameters. The automatic stations were set up at the Huancayo Observatory (Geophysical Institute of Peru) for a period of 5 months. The data set of GMX500 were evaluated comparing with the average of the 9 sensors and the WS100 was compared with an optical disdrometer Parsivel. The temperature, pressure, relative humidity, wind speed, rainfall rate, and drop size distribution were evaluated. A pair of GMX500 sensors presented high data dispersion; it was found found that the errors came from a bad configuration; once this problem was solved, good agreement was archived, with low RMSE and high correlation. It was found that the WS100 sensors overestimate the precipitation with a percentage bias close to 100% and the differences increase with the greater intensity of rain. The drop size distribution retrieved by WS100 have unrealistic behavior with higher concentrations in diameters of 1 mm and 5 mm, in addition to a flattened curve.

"New Views on the Nature of the Malguzar Dike Belt (Southern Tien-Shan)"

Ishbaev Kh D* Author Affiliations Institute of Geology and Geophysics named after Kh M Abdullaev State Committee for geology and mineral resources of the Republic of Uzbekistan, Uzbekistan Received: March 23, 2022 | Published: April 05, 2022 Corresponding author: Ishbaev Kh D, Institute of Geology and Geophysics named after Kh M Abdullaev State Committee for geology and mineral resources of the Republic of Uzbekistan, Uzbekistan DOI: 10.26717/BJSTR.2022.43.006851

Determination of engineering geophysical parameters of grounds on building sites and for seismic microzonation (methodical and metrological components of technology)

To ensure the reliability and long-term usage of high housing buildings, important industrial, infrastructural and other objects, it is necessary to carry out engineering geological investigations of grounds (near-surface rocks) as the basis of these structures. To prevent the potential danger of destruction of the objects, it is also necessary to perform microseismic investigations of the near-surface geological environment and to agree the obtained results with the engineering geological parameters in the section of the test boreholes. Engineering geological parameters, determined by geophysical methods, are named engineering geophysical parameters.
 To solve the geophysical engineering problems, including seismic microzonation, at the Institute of Geophysics of the National Academy of Sciences of Ukraine a modern investigation technology has been created. The technology is based on apparatus and methodical complex of radioactive logging, which involves gamma-ray logging (GL), density logging (DL) and neutron logging (NL). This paper presents the results of developing adequate methodical and metrological assurance of the radioactive logging complex as a key technology element.
 Complexation of methods GL, DL and NL (taking into account a priori data) and the use of the proposed approaches allow determining a wide set of engineering geophysical parameters: density, porosity, volume moisture, groundwater level, the content of shale, the content of clay minerals, water saturation, dry ground density, etc. The features of obtaining parameters by the radioactive logging complex in the zone of aeration and the zone of saturation are shown, as well as taking into account the influence of the shaliness on the determined parameters. The effectiveness of the technology has been demonstrated by specific examples and confirmed by independent laboratory measurements.

Tribute to Scientifc Contributions of Vladimir Cermak

Dr. Vladimír Čermák is currently one of the well-known research scientists in the field of global Geothermics. Initiated his early works measuring terresttial heat flow, first in Czechoslovakia but later extemnding into various other European countries. At the Geophysical Institute (Prague) he defended his PhD work (1967) and his DrSc thesis (1981). Under broad international cooperation these activities lead to the construction of the first continental scale heat flow map of Europe. Later, he become the Director of the Institute of Geophysics (1990-1998), now of the Academy of Science of the Czech Republic, where at present serves as Emeritus Professor of Sciences. He is author of more than 300 publications in Geothermics. He is well known for the pioneering works on long-term monitoring of subsurface temperatures in the famous geothermal borehole of Prague since 1990. Systematic monitoring of temperatures in this borehole continues to the present day. He was honoured at the 2015 International Union of Geodesy and Geophysics (IUGG) meeting. The prposed 2022 meeting of the Internatioanl Heat flow Commission – IHFC is named after Vladimir Cermak.

ОЦЕНКА ПАРАМЕТРОВ РАБОТОСПОСОБНОСТИ ГРОЗОПЕЛЕНГАЦИОННЫХ СИСТЕМ LS8000 И ENTLS В РЕГИОНЕ СЕВЕРНОГО КАВКАЗА

The results of a comparative analysis of data on lightning discharges obtained by lightning direction finding systems LS8000 (Vaisala, Finland) and ENTLS (Earth Networks Inc., USA) are presented. The consistency of the output data of the compared systems on the Cloud-to-Ground discharges was investigated. Observations were carried out by the High Mountain Geophysical Institute in the North Caucasus in 2019.

Analyzing the statistics for publication activity of the researchers of the S.I. Subbotin Institute of Geophysics, NAS of Ukraine for 1974—2020 in the scientometric database Webof Science

The article presents an analysis of the statistical data from the Web of Science platform on the publication activity of the researchers of the Institute of Geophysics from 1974 to 2020. 1382 articles are indexed in the Web of Science Core Collection. They have been published in 107 journals of 18 countries in 5 languages. The distribution of publications over the years clearly shows two peaks. The first one (1981—1990) is due to the fact that «Geophysical Journal International» since 1981 for 10 years has been completely translated into English and distributed abroad. During this time, half of the journal’s articles have been indexed in the Web of Science. The second peak is a consequence of the journal’s inclusion in 2015 the Web of Science. The self-citation index is 17 %, which corresponds to the world indicator for the section «Geology». Over the past twenty years, when the SCI Journal began publishing the freely available Internet Impact Factor Database of journals that are part of the Web of Science, 181 articles have been posted in 73 journals whose impact factors range from 0,046 to 7,000 with an average value of 1,785. The Hirsch index is defined for 71 researchers. Its average value is 5, which is higher for 29,6 % of researchers. The practice was discussed for using the Hirsch index in Ukraine and Russia in sollution of employee issues and allocating grants for scientific research. The Hirsch index is shown to have a wider scope of its application in our neighbors and it plays a more influential role.

Depth structure of the Gorishne-Plavninsk structure and general principles of geological and geophysical study of the Krivoy Rog-Kremenchug iron-ore strip

The article presents the results of the newest research performed by the State Enterprise «Ukrainian Geological Company» and the Institute of Geophysics of the National Academy of Sciences of Ukraine in 2021 to find out the morphology and elements of occurrence of an redeposit within the limits of the Gorishne-Plavninsk-Lavrikovsk area of the Krivoy Rog-Kremenchug iron-ore strip. In the process of geological and geophysical studies, a large body of new geological and geophysical data was obtained regarding the deep structural and morphological features of the construction of the Gorishne-Plavninsk structure (GPS), associated with the Krivoy-Rog deep fracture zone.
 Materials of reinterpretation of previously per formed ground-based magnetometric and gravimetric surveys, detailed high-altitude aeromagnetic studies and the study of the density and magnetic properties of the structure rocks, including the anisotropy of magnetic susceptibility using new equipment and techniques, gravimagnetic modeling with the construction of three-dimensional volume model of the structure lead to the conclusion that this structure is a typical drag fold with a pronounced reversal of its southern part by the right-hands hear. Its primary formation occurred as a faulted band of sedimentary-volcanogenic and extrusive formations of subvertical bedding and spreading to a depth of at least 1.5—2 km.
 A complete morphological and kinematic analogue of the GPS is the previously studied Likhmanovsk structure, located in the southern most part of the Krivoy Rog-Kremenchug strip. Many iron-ore structures of the Middle Bug area are close to it in structure and kinematics, the primary subvertical faulting and doubtful sedimentary genesis were mentioned earlier. All these data require a new approach to the study of iron-ore and some other deposits of the Ukrainian Shield associated with fault tectonics, as well as to the genesis problems and stratigraphy of rocks of the Early Precambrian.

Multi-source geographically weighted regression for regionalized ground-motion models

This work proposes a novel approach to the calibration of regionalized regression models, with particular reference to ground-motion models (GMMs), which are key for probabilistic seismic hazard analysis and earthquake engineering applications. A novel methodology, named multi-source geographically-weighted regression (MS-GWR), is developed, allowing one to (i) estimate regionalized regression models depending on multiple sources of non-stationarity (such as site- and event-dependent non-stationarities in GMMs), and (ii) make inference on the significance and stationarity of the regression coefficients. Unlike previous approaches to the problem, the proposed framework is non-parametric – in the sense of the distribution of the errors – the inference being based on a permutation scheme. MS-GWR is here used to calibrate a new regionalized ground-motion model for predicting peak ground acceleration in Italy, based on a large scale database of waveforms and metadata made available by the Italian Institute for Geophysics and Vulcanology (INGV).

Spill, Transport and Fate Model (STFM): Development and Validation

The Spill, Transport and Fate Model (STFM) is a new computational tool for modeling oil spills in Brazilian waters, developed at the Institute of Astronomy, Geophysics and Atmospheric Sciences at the University of São Paulo. The STFM was designed to assist in the analysis of environmental impact and water quality, for academic purposes and for environmental licensing studies. This work presents the formulation of the model, performance evaluations and validation of the results. These are necessary phases for the model to be made available to the public.
 Keywords: offshore contamination STFM, oil model, oil spill, water quality.

Finite-difference modeling of the wavefield on the seismometry observations on NW Black Sea shelf

In current seismic studies, special attention is given to the correctness of both the processing methods and the results of their using. In particularly, this applies to the migration procedure, which allows reproducing the deep structure of the research area directly from the observed wave field. In the Institute of Geophysics named after SI. Subbotin of the National Academy of Sciences of Ukraine, for many years, methods of migration and modeling of the wave field, which are theoretically based on the finite-difference method of solving differential equations, have been developed. Modeling the wave field makes it possible to identify useful waves in the real observed seismic field for the effective formation of a migration image of the geological environment and to confirm the correctness and accuracy of the reproduction of various types of disturbances on it. S.I. Subbotin Institute of geophysics of the National Academy of Sciences of Ukraine in 2013 on the continental slope of the northwestern part of the Black Sea, seismometry observations with reflection CDP (Common Deep Point) profiles were carried out. When processing the registered wave fields to form a depth image of the geological section, post-stack full-wave finite-difference migration was used. As a tool for assessing the correctness of the obtained results, the finite-difference modeling of the wave field is considered, which is based on the solution of the wave equation on a grid with a seven-point pattern.

Soiling accumulation impact on PV modules installed at different tilted angles in São Paulo, Brazil

The present study was carried out at the University of São Paulo (USP), in the capital campus, in Butantã, São Paulo. On the rooftop of the Photovoltaic Systems Laboratory (LSF). This study used twenty photovoltaic modules with a unit power of 20 Wp. Before the beginning of the study, the modules were exposed to natural light so that they would suffer the LID effect. Subsequently, all modules were calibrated to measure the solar irradiance, using IEC 60904-2 using a pyranometer as a secondary reference sensor. After calibration, the modules were arranged in pairs, with angles ranging from 0 to 45° as reference to the surface, with a difference between pairs of 5°. To evaluate the influence of rainfall, which is the main responsible for the natural cleaning of the modules. The pluviometric values were obtained from the meteorological station of the Institute of Astronomy, Geophysics and Atmospheric Sciences of the USP. The module allocated at 0°, “Dirty” was used as reference and all the results obtained were calculated in relation to it. The results for the 18 months of experiment showed the non-linear influence of soiling, acting in a stronger way for the less inclined angles, and after 10°, this influence, became less relevant, in comparison to the previous angle. The largest losses were found for 0° and 5°, the losses exclusively to soiling were 8.16 % and 6.82 % respectively. For angles greater than 10°, the soiling effect was attenuated, which resulted in less significant losses, for 15° the difference between the impact of dirt compared to 10° was only 0.1%. Rainfall also had a very relevant impact on the experiment. This study concluded that the optimal angle, where dirt accumulation was reduced, the rainfall cleaning and relative gains were optimized is in the range between 20° and 30°.

Three-Dimensional Model of Oil and Gas Reservoirs Based on Gaussian Beam Processing of Scattered Seismic Waves

Abstract —The efficiency of the development of an oil and gas field is largely determined by the knowledge of its geologic structure. In the recent decade, complex fractured carbonate reservoirs have attracted more and more attention. This paper is concerned with a new technology for constructing 3D images of complex reservoirs, based on Gaussian beam processing of scattered seismic waves. This technology was developed at OOO RN-KrasnoyarskNIPIneft’ in cooperation with the Trofimuk Institute of Petroleum Geology and Geophysics. To test it, a special synthetic model was constructed, which is analogous to one of the licensed objects of PAO NK Rosneft’. For this purpose, a full-scale 3D seismic was performed, which provided us with synthetic wave fields and made it possible to carry out well-controlled numerical experiments for reconstructing the geologic structure of the object of study. One of the distinctive features of the constructed digital model (digital twin) is the presentation of faults not as some ideal slip surfaces but as 3D geologic bodies filled with tectonic breccias. A series of numerical experiments was performed to simulate such breccias, the geometry of these bodies, and the geomechanical processes of fault formation. To select the parameters of the used method of discrete elements, we used the information obtained by geophysical studies in horizontal wells crossing the fault within the geologic prototype of the constructed digital model.

Urban climate change: A statistical analysis for São Paulo

In this paper we propose novel statistical decompositions of climatic time series into long-term trend, seasonal and cycle components to analyze the existence of changes in rainfall and temperature patterns. The main contribution is the generalization of these decompositions to extreme values, probability of rain and the duration of dry days. We apply these methods for the metropolitan region of São Paulo. This region is characterized by a rapid urbanization process and a high population density, which is related to increased danger and vulnerability to hydrometeorological hazards. We analyzed daily series of temperature and precipitation between 1933 and 2019 from Institute of Astronomy, Geophysics and Atmospheric Sciences of University of São Paulo (IAG-USP) and the results indicate a significant increase in the trend component of daily temperature and in the rain patterns. In addition, the analysis for annual temperature records and annual records of daily rainfall show support for the hypothesis of permanent changes in observed climatic patterns. On the other hand, there is no significant evidence of changes in the pattern of duration of dry days nor changes in the trend component for the annual maximum of dry days, indicating the stability of this component.