Article
Astronomy & Astrophysics
Anthony P. Rasca, William M. Farrell, Robert J. MacDowall, Stuart D. Bale, Justin C. Kasper
Summary: The Parker Solar Probe's first solar encounters revealed a significant amount of brief magnetic field reversals known as "switchbacks". These switchbacks evolve with radial distance from the Sun and may exhibit common changes in characteristics near closest approach.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Roberto Livi, Davin E. Larson, Justin C. Kasper, Robert Abiad, A. W. Case, Kristopher G. Klein, David W. Curtis, Gregory Dalton, Michael Stevens, Kelly E. Korreck, George Ho, Miles Robinson, Chris Tiu, Phyllis L. Whittlesey, Jaye L. Verniero, Jasper Halekas, James McFadden, Mario Marckwordt, Amanda Slagle, Mamuda Abatcha, Ali Rahmati, Michael D. McManus
Summary: The Solar Probe ANalyzer for Ions (SPAN-I) onboard NASA's Parker Solar Probe spacecraft measures the ion composition and three-dimensional distribution function of the solar wind, helping us understand the acceleration and formation of the solar wind, heating of the corona, and acceleration of particles in the inner heliosphere.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
D. Perrone, S. Perri, R. Bruno, D. Stansby, R. D'Amicis, V. K. Jagarlamudi, R. Laker, S. Toledo-Redondo, J. E. Stawarz, D. Telloni, R. De Marco, C. J. Owen, J. M. Raines, A. Settino, B. Lavraud, M. Maksimovic, A. Vaivads, T. D. Phan, N. Fargette, P. Louarn, I. Zouganelis
Summary: This study investigates the radial evolution of solar wind plasma from coronal holes using measurements from Solar Orbiter and Parker Solar Probe. The observations reveal the radial trends of proton density, magnetic field, and proton temperature, as well as the characteristics of turbulence and coherent structures at different radial distances. This work provides valuable insights into the turbulent nature of solar wind plasma and its evolution from the Sun to the Earth.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Agriculture, Multidisciplinary
Cong Wang, Yingchun Jiang, Xiaoye Li, Yikui Bai, Tieliang Wang
Summary: This study simulated the fluctuating wind speed time histories and investigated the wind-induced vibration response of a 12 m span Chinese solar greenhouse using ANSYS in the time domain. The results showed that stress and displacement under instantaneous wind loads were significantly larger than those under mean wind loads, with the most dangerous section near the front foot of the structure. The critical wind speeds for dynamic and static instability were found to be 38.7 and 58.5 m/s, respectively.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2021)
Article
Astronomy & Astrophysics
L. Adhikari, G. P. Zank, L-L Zhao, D. Telloni, T. S. Horbury, H. O'Brien, V Evans, V Angelini, C. J. Owen, P. Louarn, A. Fedorov
Summary: The study examines the evolution of anisotropic turbulence in the solar wind utilizing SolO measurements and the NI MHD turbulence model, finding that the ratio of energy components and fluctuations increase with the angle between the solar wind speed and magnetic field before decreasing again. Additionally, it is observed that solar wind turbulence is a combination of dominant 2D components and minority slab components as a function of heliocentric distance, with theoretical and observed results showing excellent agreement.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Veronika S. Heber, Kevin D. McKeegan, Robert C. J. Steele, Amy J. G. Jurewicz, Karen D. Rieck, Yunbin Guan, Rainer Wieler, Donald S. Burnett
Summary: This study presents elemental abundance data of various elements in Genesis silicon targets, including data from different solar wind regimes. The data, obtained through backside depth profiling using secondary ion mass spectrometry, provide new insights into elemental fractionation between Sun and solar wind, with noticeable differences between solar wind regimes. The study also reveals fractionation patterns among elements based on their first-ionization potential (FIP), showing consistent patterns for low-FIP elements but increasing fractionation with decreasing FIP for higher-FIP elements.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
F. S. Mozer, S. D. Bale, P. J. Kellogg, D. Larson, R. Livi, O. Romeo
Summary: This paper discusses the correlation between plasma density measurements and the surface potential of an electrically conducting satellite body. It presents a method to determine density as a function of time and frequency through least-squares fits of a function of the spacecraft potential to the measured plasma density.
ASTROPHYSICAL JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Sissel Sjoberg, Arne Andersson, Johan Backman, Bengt Hansson, Gintaras Malmiga, Maja Tarka, Dennis Hasselquist, Ake Lindstrom, Thomas Alerstam
Summary: Great reed warblers and great snipes exhibit a diel cycle in flight altitudes, being higher during the day to avoid overheating by solar radiation. Analysis of temperature data confirms that flying birds are affected by solar radiation and supports the hypothesis that it is a key factor causing the observed diel cycles in flight altitude.
Article
Astronomy & Astrophysics
Luca Sorriso-Valvo, Emiliya Yordanova, Andrew P. Dimmock, Daniele Telloni
Summary: Turbulence properties before, during, and after a coronal mass ejection (CME) detected by the Wind spacecraft in July 2012 were examined, revealing differences in turbulence characteristics and turbulent energy transfer rates in different regions.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Physics, Multidisciplinary
J. C. Kasper, K. G. Klein, E. Lichko, Jia Huang, C. H. K. Chen, S. T. Badman, J. Bonnell, P. L. Whittlesey, R. Livi, D. Larson, M. Pulupa, A. Rahmati, D. Stansby, K. E. Korreck, M. Stevens, A. W. Case, S. D. Bale, M. Maksimovic, M. Moncuquet, K. Goetz, J. S. Halekas, D. Malaspina, Nour E. Raouafi, A. Szabo, R. MacDowall, Marco Velli, Thierry Dudok de Wit, G. P. Zank
Summary: The high temperatures and strong magnetic fields of the solar corona form streams of solar wind that expand through the Solar System, with magnetic pressure dominating both ion and electron pressure. The sub-Alfvenic nature of the flow suggests suppressed magnetic reconnection at the base of the pseudostreamer, as evidenced by unusually low densities in the region.
PHYSICAL REVIEW LETTERS
(2021)
Article
Economics
Haoyang Li, Wen Lin
Summary: The cost of solar capacity is expected to drop by 45% in the next 30 years, while wind capacity cost is projected to remain relatively stable. The study shows that as solar cost declines, wind energy investment initially increases but then decreases. This results in a 12.9% increase in CO2 emissions. However, if a minimum renewable penetration rate is required, renewable investment can contribute to social welfare.
Article
Astronomy & Astrophysics
Allan R. Macneil, Mathew J. Owens, Adam J. Finley, Sean P. Matt
Summary: The study evaluates the heliospheric portion of two-step backmapping, finding that mapping using models can achieve good average agreement with observed data, but with significant standard deviation. It also suggests that previous assumptions about interplanetary acceleration and solar wind corotation height may have been overestimated, and that error cancellation may contribute to the performance of ballistic mapping.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Nindos, S. Patsourakos, A. Vourlidas, P. C. Liewer, P. Penteado, J. R. Hall
Summary: The study aimed to develop methodologies to track transient solar wind flows from rapidly varying viewpoints. Maps were constructed from Parker Solar Probe observations, with results showing different tracks in the J-map corresponding to various types of transient solar wind flows. The analysis of the Lat-map revealed PSP flying through a slightly folded streamer during perihelion.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
R. Bandyopadhyay, W. H. Matthaeus, D. J. McComas, R. Chhiber, A. Usmanov, J. Huang, R. Livi, D. E. Larson, J. C. Kasper, A. W. Case, M. Stevens, P. Whittlesey, O. M. Romeo, S. D. Bale, J. W. Bonnell, T. Dudok de Wit, K. Goetz, P. R. Harvey, R. J. MacDowall, D. M. Malaspina, M. Pulupa
Summary: This study examines the sub-Alfvenic solar wind samples encountered by the Parker Solar Probe near the Sun, investigating the turbulence, anisotropy, intermittency, and directional switchback properties and comparing them to neighboring super-Alfvenic periods.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Jingmin Zhao, Xueshang Feng, Changqing Xiang, Chaowei Jiang
Summary: This paper proposes a new mutually embedded perception model (MEPM) based on the 3D magnetohydrodynamic (MHD) equations of the solar wind plasma to reconstruct the structure of the solar corona. The MEPM utilizes neural networks and adaptive procedures to improve solution accuracy by embedding physics-based information and gradients into solar wind parameters data. The MEPM demonstrates accurate results in capturing the leading structures of the solar corona and is consistent with observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. Zaslavsky, I Mann, J. Soucek, A. Czechowski, D. Pisa, J. Vaverka, N. Meyer-Vernet, M. Maksimovic, E. Lorfevre, K. Issautier, K. Rackovic Babic, S. D. Bale, M. Morooka, A. Vecchio, T. Chust, Y. Khotyaintsev, V Krasnoselskikh, M. Kretzschmar, D. Plettemeier, M. Steller, S. Stverak, P. Travnicek, A. Vaivads
Summary: The study shows that Solar Orbiter RPW is a suitable instrument for interplanetary dust studies, with the dust detection algorithm implemented in the TDS subsystem being an efficient tool for estimating fluxes. These first results are promising for the continuation of the mission, especially for the in situ study of the inner Solar System dust cloud outside of the ecliptic plane, which Solar Orbiter will be the first spacecraft to explore.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Jana Safrankova, Zdenek Nemecek, Frantisek Nemec, Victor Montagud-Camps, Daniel Verscharen, Andrea Verdini, Tereza Durovcova
Summary: This study presents a large statistical analysis of fluctuation anisotropy in magnetic field and solar wind velocity. The results show that most magnetic field fluctuations align with the mean magnetic field, while velocity fluctuations tend to be more uniformly distributed. Additionally, numerical MHD simulations are in agreement with the experimental findings.
ASTROPHYSICAL JOURNAL
(2021)
Article
Environmental Sciences
Gilbert Pi, Alexander Pitna, Guo-Qing Zhao, Zdenek Nemecek, Jana Safrankova, Tsung-Che Tsai
Summary: Long-lasting radial interplanetary magnetic field intervals have interesting properties, such as low fluctuation amplitude, increased spectral power with cone angle, increased isotropy in proton temperature, higher occurrence rate of waves, and absence of preferred polarization. These characteristics suggest a different development of turbulence under the radial IMF structure compared to the typical structure.
Article
Physics, Multidisciplinary
S. P. Savin, V. V. Lyakhov, V. M. Neshchadim, L. M. Zelenyi, Z. Nemecek, J. Shafrankova, C. Wang, S. Klimov, S. A. Skalskii, M. O. Ryazantseva, L. S. Rakhmanova, J. Blecki, L. A. Lezhen
Summary: Resonant modes with frequencies of 0.02-0.25 mHz detected from the bow shock to the outer magnetosphere remain unexplained. In this study, a circular plate model for the bow shock is proposed, predicting resonant modes at frequencies of 0.02-0.3 mHz or lower. The detection of these model resonances is demonstrated based on satellite data, with the resonance near 0.1 mHz observed continuously in the magnetosheath for 17 hours. Resonant bow shock modes can produce broadband coherent coupling, which is important for nonlinear physics.
JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS
(2022)
Article
Geochemistry & Geophysics
Praveen Basuvaraj, Frantisek Nemec, Zdenek Nemecek, Jana Safrankova
Summary: The Martian ionosphere has unique structures different from Earth and Venus, and integrated observations show evidence of ionospheric plasma depletions independent of seasonal variations. These depletions are more prominent on the nightside, possibly occurring in regions with strong crustal magnetic fields, and are bubble-like structures elongated horizontally.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
Jan Wild, Jakub Cizek, Libor Nouzak, Jiri Pavlu, Jana Safrankova, Zdenek Nemecek, Jakub Vaverka, Dalibor Nosek, Tomas Burian, Anna Wildova, Jan Broulim
Summary: We present the first laboratory experiment investigating the interaction between a cosmic dust simulant and positrons emitted from a Na-22 radioisotope. By accurately measuring the charge of micrometer-sized SiO2 dust grains, we observed +1 e steps, indicative of positron annihilation inside the grain. The rate of these charging events aligns well with predictions from a model based on the continuous slowing down approximation of energetic positrons within the grain. Additionally, we attributed less frequent charging steps larger than +1 e to the emission of secondary electrons during the positron slowing down process. The coefficient of secondary electron emission was found to be approximately inversely proportional to the grain radius. Based on our experimental findings, we propose a potential scenario for charging in interstellar dark clouds.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
A. Salohub, J. Safrankova, Z. Nemecek, F. Nemec, G. Pi
Summary: A broad statistical study was conducted on the evolution of ultra-low frequency waves in the terrestrial foreshock around the Moon. The study shows that these waves can grow or decay towards the bow shock under the interplanetary magnetic field. The growth rate is found to be larger for compressive variations of the magnetic field strength and density. Nonlinear effects can also decrease the growth rate.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
K. Grygorov, Z. Nemecek, J. Safrankova, J. Simunek, O. Gutynska
Summary: The magnetopause is usually seen as a boundary where the pressures of the solar wind and the geomagnetic field balance each other, neglecting the plasma pressure inside the magnetopause. However, studies have shown that there is an excess of pressure in the magnetosheath, and observations reveal that the magnetic field in the magnetosheath can be larger than in the magnetosphere. Additionally, the presence of a dense cold ion population affects the pressure balance and the rate of magnetic flux transport. These findings explain the contradiction observed in previous papers regarding the lack of magnetospheric pressure at the magnetopause.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Jana Safrankova, Zdenek Nemecek, Frantisek Nemec, Daniel Verscharen, Timothy S. Horbury, Stuart D. Bale, Lubomir Prech
Summary: We conduct a comprehensive statistical study on the evolution of compressive and noncompressive magnetic field fluctuations in the inner heliosphere. Using data from Parker Solar Probe and Solar Orbiter at different distances from the Sun, we analyze solar wind power spectra of magnetic field fluctuations in the inertial and kinetic frequency ranges. Our findings reveal that the spectrum in the inertial range becomes steeper as the distance from the Sun increases, while in the kinetic range, the spectral indices increase with distance and remain approximately constant towards 1 au. The radial profiles of spectral slopes, fluctuation amplitudes, spectral breaks, and their relationships undergo rapid changes near 0.4 au.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
M. Aghabozorgi Nafchi, F. Nemec, G. Pi, Z. Nemecek, J. Safrankova, K. Grygorov, J. Simunek
Summary: In this study, a statistical analysis of nearly 15,000 magnetopause crossings from multiple satellite data is presented. The results show that the interplanetary magnetic field (IMF) has a significant impact on the location of the magnetopause, independent of the solar wind dynamic pressure. The IMF clock angle is found to be a key factor controlling the magnetopause distance, which is not accounted for in existing empirical models. Additionally, the IMF B-y component can induce a dawn-dusk asymmetry of the magnetopause shape during very low Alfven Mach numbers (M-A < 4). These findings are in qualitative agreement with magnetohydrodynamic models.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Soil Science
Lenka Pavlu, Tereza Zadorova, Jiri Pavlu, Vaclav Tejnecky, Ondrej Drabek, Jessica Reyes Rojas, Saven Thai, Vit Penizek
Summary: This study demonstrates the potential of diffuse reflectance infrared spectroscopy (DRIFT) in describing the stratigraphy and soil properties of deep colluvial profiles in different regions in the Czech Republic. The normalization of the spectrum was found to be effective in determining the carbonate content and organic carbon content of the soils. It also proved to be a useful tool in identifying the boundaries between soil layers and provides comprehensive information about the soil and its components.
SOIL & TILLAGE RESEARCH
(2023)
Article
Physics, Multidisciplinary
S. P. Savin, V. V. Lyakhov, V. M. Neshchadim, L. M. Zelenyi, Z. Nemecek, J. Safrankova, S. Klimov, S. A. Skalsky, M. O. Ryazantseva, L. S. Rakhmanova, C. Wang, H. Li, J. Blecki, J-L Rauch, L. Kozak, A. Suvorova, L. A. Lezhen
Summary: The study investigates the linear and nonlinear resonances and cascades impacting the interaction between collisionless plasma flow and a magnetic barrier, using the near-Earth magnetopause as a case study. The research emphasizes on the structure of spectra and bi-spectra of fluctuations near the magnetopause and resonances at frequencies 0.05-0.5 mHz. It also explores the nonlinear three-wave cascade interaction of compressible and incompressible waves, providing insights into the excitation of resonances without a close coincidence of frequencies.
JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS
(2021)
