8. Afterthoughts

2018 ◽  
pp. 127-130
Author(s):  
William Lowrie
Keyword(s):  
Complex Nature ◽  
Geophysical Research ◽  
The Earth

Geophysics has made many important advances towards understanding the behaviour and properties of planet Earth. Geophysical research continues to make discoveries and developments that benefit society. Many problems presented by the Earth—such as the prediction of both the time and location of an earthquake—have been researched by geophysicists for decades, but remain unsolved because of the complex nature of their causes. ‘Afterthoughts’ explains that earth scientists cannot control the natural events that occur, but can only observe and try to understand them. The equipment for attaining these goals improves continually, in a remarkably rapid and encompassing manner. Land-based methods are now augmented in several fields by remarkable observations from space.

Recurrence-Based Quantification of Multi-Scale Dynamical Complexity in the Earth’s Magnetosphere

2021 ◽  
Author(s):  
Reik Donner
Keyword(s):  
Network Analysis ◽  
Space Weather ◽  
Geomagnetic Field ◽  
Magnetic Storms ◽  
Temporal Organization ◽  
Geophysical Research ◽  
Multi Scale ◽  
Dynamical Complexity ◽  
The Earth ◽  
Relevant Effect

<p>The Earth’s magnetosphere is characterized by a considerable degree of dynamical complexity resulting from the interaction of different multiscale processes, which can be both directly driven/triggered by changes of the interplanetary medium condition, and due to internal processes of the magnetosphere. This complexity can be characterized by following both “classical” and “new” dynamical system tools. Recent work has demonstrated that recurrence plot based techniques may play a pivotal role in such an assessment.</p><p>In this presentation, I will summarize some recent results on applications of recurrence quantification analysis and recurrence network analysis to different geomagnetic indices (Dst, SYM-H, ASY-H, AE) reflecting the variability of the Earth’s electromagnetic environment at different time-scales and magnetic latitudes. In addition, the same techniques are applied to some essential properties of the solar wind which are likely to have a relevant effect on geomagnetic field fluctuations and might serve as triggers of instability leading to geospace magnetic storms and/or magnetospheric substorms. The obtained findings underline that dynamical fluctuations of the geomagnetic field during periods of magnetospheric quiescence and storminess indeed exhibit distinctively different levels of dynamical complexity. Moreover, they provide additional evidence for a time-scale separation in magnetospheric dynamics that is further characterized by employing some multi-scale version of recurrence analysis utilizing a continuous wavelet transform of the signals of interest. The corresponding results can be of potential relevance for the development of improved approaches for space weather modelling and forecasting.</p><p> </p><p>References:</p><p>R.V. Donner, V. Stolbova, G. Balasis, J.F. Donges, M. Georgiou, S. Potirakis, J. Kurths: Temporal organization of magnetospheric fluctuations unveiled by recurrence patterns in the Dst index. Chaos, 28, 085716 (2018)</p><p>R.V. Donner, G. Balasis, V. Stolbova, M. Georgiou, M. Wiedermann, J. Kurths: Recurrence based quantification of dynamical complexity in the Earth's magnetosphere at geospace storm timescales. Journal of Geophysical Research - Space Physics, 124, 90-108 (2019)</p><p>J. Lekscha, R.V. Donner: Areawise significance tests for windowed recurrence network analysis. Proceedings of the Royal Society A, 475 (2228), 20190161 (2019)</p><p>T. Alberti, J. Lekscha, G. Consolini, P. De Michelis, R.V. Donner: Disentangling nonlinear geomagnetic variability during magnetic storms and quiescence by timescale dependent recurrence properties. Journal of Space Weather and Space Climate, 10, 25 (2020)</p>

An unknown maximum lag-correlation between rainfall and aerosols at 140-160 minutes

2021 ◽  
Author(s):  
Pinhas Alpert ◽  
Haim Shafir ◽  
Emily Elhacham
Keyword(s):  
Time Series ◽  
Time Scales ◽  
Atmospheric Chemistry ◽  
Numerical Study ◽  
Aerosol Concentration ◽  
Hygroscopic Growth ◽  
Plain Language ◽  
Geophysical Research ◽  
Near Surface ◽  
The Earth

<p>Keywords:</p><p>Scavenging process, Rainfall, Aerosols, Lag correlation, Rainfall-aerosol processes</p><p>Abstract</p><p>Rainfall and aerosols play major roles in the Earth climate system and substantially influence our life. Here, the focus is on the local near-surface aerosol/rainfall correlations with time-scales of minutes to days. We investigated 29 experiments including 14 specific rain events, with time resolutions of daily and 60, 30, 10 minutes at ten stations in Israel and California. The highest negative correlations were consistently at a positive lag of about 140-160 minutes where a positive lag means that the aerosol time-series follows that of the rain. The highest negative value is suggested to be the probable outcome of immediate scavenging along with the rise in aerosol concentration after rain depending on aerosol sources, hygroscopic growth and transport. The scavenging dominance is expressed by the mostly negative lag-correlation values in all experiments. In addition, the consistent lack of significant correlation found at negative lags suggest a weak aerosol effect on precipitation (Gryspeerdt et al., 2015).</p><p>Plain Language Summary: Rainfall and atmospheric particles (aerosols) play significant roles in the Earth atmosphere and largely influence our weather and climate. The relations between near-surface aerosol and rainfall on time scales of minutes to days are studied, employing correlations in 10 meteorological stations in Israel and California. The highest negative correlations were consistently at a positive lag of about 140-160 minutes. A positive lag means that the aerosol time-series follows that of the rain. The highest negative correlation value is suggested to be the outcome of scavenging along with the rise in aerosol concentration after rain depending on the sources of aerosols, hygroscopic growth and transport. <strong>Furthermore, our approach provides a more fundamental insight into the local, near-surface rain-aerosol interactions, in contrast to many aerosol-rainfall studies that are climatological and with the tele-connection approach (Alpert et al., 2008), which involves other processes over distances of a few km up to even large synoptic scales.</strong></p><p>            </p><p><strong>Relevant References:</strong></p><p>Alpert, P., Halfon, N., & Levin, Z. (2008). Does Air Pollution Really Suppress Precipitation in Israel? Journal of Applied Meteorology and Climatology. https://doi.org/10.1175/2007jamc1803.1</p><p>Barkan, J., & Alpert, P. (2020). Red Snow occurrence in Eastern Europe - A case study. Weather. https://doi.org/10.1002/wea.3644</p><p>Gryspeerdt, E., Stier, P., White, B. A., & Kipling, Z. (2015). Wet scavenging limits the detection of aerosol effects on precipitation. Atmospheric Chemistry and Physics, 15(13), 7557–7570.</p><p>Tsidulko, M., Krichak, S. O., Alpert, P., Kakaliagou, O., Kallos, G., & Papadopoulos, A. (2002). Numerical study of a very intensive eastern Mediterranean dust storm, 13-16 March 1998. Journal of Geophysical Research: Atmospheres. https://doi.org/10.1029/2001jd001168</p>

The Conditional Contributions of Electromagnetism and QED To Natural Hazards in Both Nano and Macro Cosmic Scales

2020 ◽  
Author(s):  
Taner Sengor
Keyword(s):  
Natural Hazards ◽  
Van Der Waals ◽  
Vertical Direction ◽  
P Wave ◽  
Secondary Wave ◽  
S Wave ◽  
Geophysical Research ◽  
Tectonic Plates ◽  
The Earth ◽  
Qed Effects

<p>The Earth itself with its inwards and outwards is a unique and complete system according to all events effecting the Earth<sup>1</sup>. All the natural events involving hazards are the results of self-controlling mechanism of the complex network of this unique system. Several contributions and reports presented this fact. The classical approaches trying to explain earthquake events, say EQs, and related phenomena may be taken as approximations working for the EQs less than 5.9 Richter in magnitude according to observations coming from the application of this approach. The EQs bigger than 5.9 Richter involve very different ingredients given with dynamics based on the gravity in classical geophysics<sup>1</sup>. The ranges of (5.9+n, 5.9+n+1) for every n=1, 2, 3, ... present different formulations due to validity of the approximations and orders of the variables as relative to the energy density and frequency levels.  The fact in here comes with the compactness coming with the electromagnetically equivalent models<sup>1</sup>.</p><p> </p><p>The planetary movements effect both the mechanics and dynamics of tectonic plates like tidal action of Pascal’s law modified with stochastic interactions. The Earth’s plates may move and collide with each other due to the forces generated by these displacements. The Primary wave comes from these mechanics of plates under planetary effects, tidal effects, and/or effects of extended Pascal’s and Archimedes’ principles for compressible liquids involving non-adiabatic gasses in semi-open containers. All these effects are effective in vertical direction, totally. P wave is a result of these forces generated by the dynamics of collision of plate-to-plate, plate-to-sea, plate-to-ocean, and/or plate-to-tidal processes coming from planetary motions and acts between plates. Secondary wave come from the effects of Casimir-Polder forces and Van der Waals potentials generated by the nano-displacements occurring among touch-to-touch phases of plates just at the end of P wave phases. These QED effects are effective in horizontal direction in total iff they can generate an EQ. If the plates touch to each other with the effect of forces coming from P wave then this induces Van der Waals potentials and forces like Casimir-Polder force work on the plates generating big amount of energy then big EQs can come to truth. It is possible to model the P wave phases with the deterministic ingredients and processes; however, modelling the S wave phases are not possible without stochastic ingredients and processes. The processes like storms, typhoon, etc. developing with the atmospheric events generate the similar effects. The waves coming with EQs propagate in inflective trajectories; therefore, these waves propagate in inflective spaces. This analysis illustrates the gravity interactions of the Earth with other planets generating electromagnetic interactions in both nano-scale and quantum level in Earth’s interior as the actual trigger of EQs. The excessive fall works like the insurance for EQs preventing the occurrence of significant EQs and so, reducing the huge damage arriving from significant and/or bigger EQs.</p><p>-------------------</p><p><sup>1</sup>Sengor T, “The Globally Compact Multi-Network of the Earth: the self-controlling mechanisms in natural hazards above significant level,” Geophysical Research Abstracts, Vol. 21, EGU2019-17127,2019, General Assembly 2019.</p>

scholarly journals First-principles modeling of geomagnetically induced electromagnetic fields and currents from upstream solar wind to the surface of the Earth

2007 ◽  
Vol 25 (4) ◽  
pp. 881-893 ◽  
Author(s):  
A. Pulkkinen ◽  
M. Hesse ◽  
M. Kuznetsova ◽  
L. Rastätter
Keyword(s):  
Solar Wind ◽  
Electromagnetic Fields ◽  
Space Weather ◽  
First Principles ◽  
Normal Operation ◽  
Complex Nature ◽  
Geomagnetically Induced Currents ◽  
Modeling Process ◽  
The Earth ◽  
Upstream Solar Wind

Abstract. Our capability to model the near-space physical phenomena has gradually reached a level enabling module-based first-principles modeling of geomagnetically induced electromagnetic fields and currents from upstream solar wind to the surface of the Earth. As geomagnetically induced currents (GIC) pose a real threat to the normal operation of long conductor systems on the ground, such as high-voltage power transmission systems, it is quite obvious that success in accurate predictive modeling of the phenomenon would open entirely new windows for operational space weather products. Here we introduce a process for obtaining geomagnetically induced electromagnetic fields and currents from the output of global magnetospheric MHD codes. We also present metrics that take into account both the complex nature of the signal and possible forecasting applications of the modeling process. The modeling process and the metrics are presented with the help of an actual example space weather event of 24–29 October 2003. Analysis of the event demonstrates that, despite some significant shortcomings, some central features of the overall ionospheric current fluctuations associated with GIC can be captured by the modeling process. More specifically, the basic spatiotemporal morphology of the modeled and "measured" GIC is quite similar. Furthermore, the presented user-relevant utility metrics demonstrate that MHD-based modeling can outperform simple GIC persistence models.

Phase stabilities and Fe/Sr/La partitioning between magnesite (MgCO3) and mantle silicates at lower mantle conditions.

2020 ◽  
Author(s):  
Lélia Libon ◽  
Georg Spiekermann ◽  
Karen Appel ◽  
Nicole Biedermann ◽  
Christian Albers ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Silicate Glass ◽  
Lower Mantle ◽  
Iron Silicide ◽  
Melting Curve ◽  
Geophysical Research ◽  
The Earth ◽  
Mantle Silicates ◽  
Laser Heated

<p>Carbonates appear to be one group of the main carbon-bearing minerals in the Earth’s interior. Inclusions of carbonates in diamonds of lower mantle origin support the assumption that they are present even in the Earth’s lower mantle. Although the carbonates’ phase diagrams have been intensively studied, their stability in presence of mantle silicates at deep mantle conditions (>25 GPa) remains unclear. Furthermore, the carbonate inclusions show a high REE enrichment. This raises questions on the distribution of trace elements between carbonates and silicates and on the possible role of carbonates as trace element carrier in the Earth’s mantle.</p><p>Numerous studies show that magnesite is likely to be the major solid carbonate carried by subduction into the Earth’s lower mantle. We investigated the stability of MgCO<sub>3</sub> in presence of mantle silicates and the Fe, Sr and La partitioning in high-pressure and high-temperature experiments. One set of experiments was conducted with multi-anvil presses at BGI, Bayreuth, at conditions ranging from 24 GPa to 30 GPa and 2000 K. The investigated reaction is between natural magnesite and (Mg,Fe)SiO<sub>3</sub>-glasses doped with either Sr or La. Preliminary data from the multi-anvil press at 24 GPa and 2000K show the onset of carbonate melting which is consistent with the previous study of the melting curve in the enstatite-magnesite system [1]. Decomposition of MgCO<sub>3</sub> is not observed, in contrast to experiments using magnesite and SiO<sub>2</sub> as starting materials [2], suggesting that MgCO<sub>3</sub> is stable at these conditions in the presence of silicates phases. The silicate glass react to bridgmanite (Mg,Fe)SiO<sub>3</sub> as well as stishovite SiO<sub>2</sub> and magnesiowüstite (Mg,Fe)O. The Fe-Mg partitioning coefficient between bridgmanite and magnesite calculated in this study is ~2 and in agreement with previous experiments at similar conditions [3].<br>Laser-heated diamond anvil cell (LH-DAC) experiments were performed at University of Potsdam [4] at conditions 30 to 40 GPa and 1800 to 2300 K. The run products were characterized in-situ at high-pressure by XRD and XRF mapping at the P02.2 beamline at PETRA III. Our data show a transformation of the starting silicate glass into bridgmanite. We also observed stishovite and magnesiowüstite in the center of the hotspot where the temperature had reached >2000 K. In this case, the presence of magnesiowüstite might be the result of MgCO<sub>3 </sub>decomposition at higher temperature. Additional TEM analyses on the post-mortem sample will allow us to further characterize the different phases present in the laser-heated hotspot.</p><p>[1] Thompson et al. (2014) Chemistry and mineralogy of the earth’s mantle. Experimental determination of melting in the systems enstatite-magnesite and magnesite-calcite from 15 to 80 GPa. American Mineralogist 99(8-9), 1544-1554.<br>[2] Drewitt et al. (2019) The fate of carbonate in oceanic crust subducted into Earth’s lower mantle. EPSL 511, 213-222<br>[3] Martinez, et al. (1998). Experimental investigation of silicate-carbonate system at high pressure and high temperature. Journal of Geophysical Research: Solid Earth, 103(B3), 5143-5163.<br>[4] Spiekermann et al. (2020). A portable on-axis laser heating system for near-90° X-ray spectroscopy: Application to ferropericlase and iron silicide. Journal of Synchrotron Radiation. (accepted)</p>

scholarly journals Preface

2014 ◽  
Vol 57 (3) ◽  
Author(s):  
Domenico Di Mauro
Keyword(s):  
Polar Regions ◽  
Physical Processes ◽  
Geophysical Research ◽  
International Polar Year ◽  
Remote Areas ◽  
The Earth ◽  
International Polar

<p>The following collection of papers is dedicated to geophysical research and experiments conducted in the polar regions of the Earth, during a period centered around the last third International Polar Year (IPY, 2007-2009) and extending into succeeding years. The issues celebrating the IPY are intended to stimulate interest in the physical processes occurring at the polar regions, with the involvement of all the nations that collaborate and play key roles in these remote areas. [...]</p>

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

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