scholarly journals Tide-induced magnetic signals and their errors derived from CHAMP and Swarm satellite magnetometer observations

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Jan Saynisch-Wagner ◽  
Julien Baerenzung ◽  
Aaron Hornschild ◽  
Christopher Irrgang ◽  
Maik Thomas
Keyword(s):  
Magnetic Fields ◽  
Heat Content ◽  
Simultaneous Estimation ◽  
Error Covariance ◽  
Error Distributions ◽  
Mantle Conductivity ◽  
Swarm Satellite ◽  
First Time ◽  
Champ Data ◽  
Global Mean

AbstractSatellite-measured tidal magnetic signals are of growing importance. These fields are mainly used to infer Earth’s mantle conductivity, but also to derive changes in the oceanic heat content. We present a new Kalman filter-based method to derive tidal magnetic fields from satellite magnetometers: KALMAG. The method’s advantage is that it allows to study a precisely estimated posterior error covariance matrix. We present the results of a simultaneous estimation of the magnetic signals of 8 major tides from 17 years of Swarm and CHAMP data. For the first time, robustly derived posterior error distributions are reported along with the reported tidal magnetic fields. The results are compared to other estimates that are either based on numerical forward models or on satellite inversions of the same data. For all comparisons, maximal differences and the corresponding globally averaged RMSE are reported. We found that the inter-product differences are comparable with the KALMAG-based errors only in a global mean sense. Here, all approaches give values of the same order, e.g., 0.09 nT-0.14 nT for M2. Locally, the KALMAG posterior errors are up to one order smaller than the inter-product differences, e.g., 0.12 nT vs. 0.96 nT for M2. Graphical Abstract

How is the Balance of a Forecast Ensemble Affected by Adaptive and Nonadaptive Localization Schemes?

2015 ◽  
Vol 143 (9) ◽  
pp. 3680-3699 ◽  
Author(s):  
Ross N. Bannister
Keyword(s):  
Forecast Error ◽  
Covariance Matrices ◽  
Error Statistics ◽  
Error Covariance ◽  
Localization Scheme ◽  
Adaptive Schemes ◽  
Convective Scale ◽  
Free Parameters ◽  
Hydrostatic Balance ◽  
First Time

Abstract This paper investigates the effect on balance of a number of Schur product–type localization schemes that have been designed with the primary function of reducing spurious far-field correlations in forecast error statistics. The localization schemes studied comprise a nonadaptive scheme (where the moderation matrix is decomposed in a spectral basis), and two adaptive schemes: a simplified version of Smoothed Ensemble Correlations Raised to a Power (SENCORP) and Ensemble Correlations Raised to a Power (ECO-RAP). The paper shows, the author believes for the first time, how the degree of balance (geostrophic and hydrostatic) implied by the error covariance matrices localized by these schemes can be diagnosed. Here it is considered that an effective localization scheme is one that reduces spurious correlations adequately, but also minimizes disruption of balance (where the “correct” degree of balance or imbalance is assumed to be possessed by the unlocalized ensemble). By varying free parameters that describe each scheme (e.g., the degree of truncation in the schemes that use the spectral basis, the “order” of each scheme, and the degree of ensemble smoothing), it is found that a particular configuration of the ECO-RAP scheme is best suited to the convective-scale system studied. According to the diagnostics this ECO-RAP configuration still weakens geostrophic and hydrostatic balance, but overall this is less so than for other schemes.

scholarly journals Background Error in WRF Model

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Data Assimilation ◽  
Physical Properties ◽  
Covariance Matrix ◽  
Numerical Weather Prediction ◽  
Weather Prediction ◽  
Wrf Model ◽  
Background Error ◽  
Numerical Weather ◽  
Error Covariance ◽  
First Time

WRF model have been tuned and tested over Georgia’s territory for years. First time in Georgia theprocess of data assimilation in Numerical weather prediction is developing. This work presents how forecasterror statistics appear in the data assimilation problem through the background error covariance matrix – B, wherethe variances and correlations associated with model forecasts are estimated. Results of modeling of backgrounderror covariance matrix for control variables using WRF model over Georgia with desired domain configurationare discussed and presented. The modeling was implemented in two different 3DVAR systems (WRFDA andGSI) and results were checked by pseudo observation benchmark cases using also default global and regional BEmatrixes. The mathematical and physical properties of the covariances are also reviewed.

scholarly journals Kertsopoulos Innovation: The Three Multi-plane Polarities and the Three Interactions and Schematic Representations in the Sense of the General Cause of the Dynamic Difference

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Magnetic Fields ◽  
Magnetic System ◽  
State Of The Art ◽  
Magnetic Devices ◽  
Know How ◽  
Patented Invention ◽  
Scientific Laws ◽  
First Time ◽  
Multiple Interactions

As it is known: in the state of the art, the like and the unlike polarity between two magnets remains independent of the distance between them. According to the invention: “Magnetic System of Three Interactions”, International office of patents WIPO-PCT, bearing the No WO/2013/136097of the inventor Georgios K. Kertsopoulos, the like and the unlike polarity between two magnetic constructions depends on the distance between them [1], [2], [3], [4], [5], [6], [7], [8], [9], [10]. The know-how of the invention makes it possible for interacting magnetic constructions to possess and perform interchangeable more than 96 polarities and interactions. Polarities and magnetic fields can in multiple ways interchange, depending on the varying distance between two interacting confronted magnetic constructions, offering many new variable design capabilities. For the first time, new types of poles are created, for example: simultaneous like-unlike poles or simultaneous unlike-like poles are created, causing stable or unstable balance as an interaction; also, for the first time in magnetism, new types of magnetic fields are formed never before observed, for example: remote fields of very strong attraction, without however, the contact of the magnetic constructions. The magnetic devices that perform these multiple interactions are fully patented internationally, published in a book in English, by the inventor a book in English, by the inventor [11]. The new scientific laws and principles, revealed through these experiments enrich the very basics, the foundation of magnetism, since many new types of polarities and interactions are introduced and are made possible for the first time in science and technology. In figure 1 of the article we observe the division and determination of the empty air space, between the magnetic constructions, at three distances and two boundaries which apply both for the like and the unlike front poles and in figure 2 we observe the three typical spatial distances, the three multi-plane polarities and the three interactions with properties and with spatial boundaries and interactions based on the bundles of the dynamic lines between the two magnetic constructions, on the guide, when the poles of the front poles of the arrangements are initially like. Furthermore, in figure 7 we observe a schematic representation of the three different fields (175), (177) and (178) between the above-mentioned magnetic arrangements of the constructions of the invention, with initially like front poles, in the sense of the general cause of the dynamic difference. This article is in continuation of the following published article that introduces the reader to the invention’s technology: Georgios K. Kertsopoulos (2018) Innovation article: 36 over passed restrictions of magnetism achieved by the 96 multiple magnetic polarities-interactions performed by the Kertsopoulos world patented invention vs. the known two. Advances in Nanoscience and nanotechnology [12]. https://www.opastonline.com/wp-content/uploads/2018/12/36-over-passed-restrictions-of-magnetism-achieved-by-the-96- multiple-magnetic-polarities-interactions-performed-by-the-kertsopoulos-world-ann-18.pdf?fbclid=IwAR1jYPFME5mhX2FLbKKTPAdu0YMe3FqHtoUdoRoeao8mKIp1GRuWeovEaA

scholarly journals Estimates of climate system properties incorporating recent climate change

2018 ◽  
Vol 4 (1/2) ◽  
pp. 19-36 ◽  
Author(s):  
Alex G. Libardoni ◽  
Chris E. Forest ◽  
Andrei P. Sokolov ◽  
Erwan Monier
Keyword(s):  
Climate Change ◽  
Surface Temperature ◽  
21St Century ◽  
Climate Sensitivity ◽  
Temperature Rise ◽  
Heat Content ◽  
Climate System ◽  
Model Parameters ◽  
Aerosol Forcing ◽  
Global Mean

Abstract. Historical time series of surface temperature and ocean heat content changes are commonly used metrics to diagnose climate change and estimate properties of the climate system. We show that recent trends, namely the slowing of surface temperature rise at the beginning of the 21st century and the acceleration of heat stored in the deep ocean, have a substantial impact on these estimates. Using the Massachusetts Institute of Technology Earth System Model (MESM), we vary three model parameters that influence the behavior of the climate system: effective climate sensitivity (ECS), the effective ocean diffusivity of heat anomalies by all mixing processes (Kv), and the net anthropogenic aerosol forcing scaling factor. Each model run is compared to observed changes in decadal mean surface temperature anomalies and the trend in global mean ocean heat content change to derive a joint probability distribution function for the model parameters. Marginal distributions for individual parameters are found by integrating over the other two parameters. To investigate how the inclusion of recent temperature changes affects our estimates, we systematically include additional data by choosing periods that end in 1990, 2000, and 2010. We find that estimates of ECS increase in response to rising global surface temperatures when data beyond 1990 are included, but due to the slowdown of surface temperature rise in the early 21st century, estimates when using data up to 2000 are greater than when data up to 2010 are used. We also show that estimates of Kv increase in response to the acceleration of heat stored in the ocean as data beyond 1990 are included. Further, we highlight how including spatial patterns of surface temperature change modifies the estimates. We show that including latitudinal structure in the climate change signal impacts properties with spatial dependence, namely the aerosol forcing pattern, more than properties defined for the global mean, climate sensitivity, and ocean diffusivity.

scholarly journals New Infrared Measurements of Magnetic Fields on Cool Stars

1994 ◽  
Vol 154 ◽  
pp. 493-497 ◽  
Author(s):  
Steven H. Saar
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ir Spectra ◽  
Preliminary Analysis ◽  
M Dwarfs ◽  
Pressure Balance ◽  
Infrared Measurements ◽  
Cool Stars ◽  
Rs Cvn Variables ◽  
First Time

I present a preliminary analysis of IR spectra of five K and M dwarfs and two RS CVn variables. Evidence for significant magnetic flux is found on several stars, a number of which are detected for the first time. Field strengths (B) on the RS CVn variables are lower than in the active dwarfs, consistent with the concept of pressure balance limiting B in stellar photospheres. I compare the results with previous measurements.

Introductory remarks

1994 ◽  
Vol 349 (1690) ◽  
pp. 169-170
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Royal Society ◽  
Lunar Regolith ◽  
The Moon ◽  
Global Magnetic Field ◽  
The Subject ◽  
Planetary Missions ◽  
Speculative Hypothesis ◽  
First Time

This year marks not only the twenty-fifth anniversary of the first manned landing on the Moon ( Apollo 11 ) but also the thirty-fifth anniversary of the first planetary missions. The latter was the Soviet Luna 1 and 2 carrying magnetometers to test whether the Moon possessed a global magnetic field. Luna 1 passed the Moon but Luna 2 crash landed, both showed that the Moon had no magnetic field as large as 50 or 100 y (1 y = 10 -5 G = 10 -9 T). Such an experiment had been proposed by S. Chapman ( Nature 160, 395 (1947)) to test a speculative hypothesis concerning magnetic fields of cosmic bodies by P. M. S. Blackett ( Nature 159, 658 (1947)). Chapman’s suggestion was greeted by general amusement: 12 years later it was accomplished. Also two years after the launch of Sputnik 1 in 1957, Luna 3 was launched and for the first time viewed the far side of the Moon on 9 October, 1959. Laboratories from many countries were invited by NASA to take part in the analysis of rocks returned from the Apollo missions and later from the Soviet automated return of cores from the lunar regolith. British laboratories were very active in this work, and a review of the results of the new understanding of the Moon as a result of space missions formed the subject of a Royal Society Discussion Meeting in 1975 (published in Phil. Trans. R. Soc. Lond . A 285). British laboratories received samples from the automated Soviet missions that took cores from the regolith and returned them to Earth. Work on Luna 16 and 20 samples were published in Phil. Trans. R. Soc. Lond . A 284 131-177 (1977) and on Luna 24 in Phil. Trans. R. Soc. Lond . A 297 1-50 (1979).

scholarly journals Binary and multiple magnetic Ap/Bp stars

2013 ◽  
Vol 9 (S302) ◽  
pp. 317-319
Author(s):  
Denis Rastegaev ◽  
Yuri Balega ◽  
Vladimir Dyachenko ◽  
Alexander Maksimov ◽  
Evgenij Malogolovets
Keyword(s):  
Magnetic Fields ◽  
Proper Motion ◽  
Special Astrophysical Observatory ◽  
Full Version ◽  
Short Period ◽  
Magnetic Stars ◽  
Total Fraction ◽  
Academy Of Sciences ◽  
First Time ◽  
Prominent Peak

AbstractWe present the results of speckle interferometric observations of 273 magnetic stars most of which are Ap/Bp type. All observations were made at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolved 58 binary and 5 triple stars into individual components. Almost half of these stars were astrometrically resolved for the first time. The fraction of speckle interferometric binaries/multiples in the sample of stars with confirmed magnetic fields is 23%. We expect that the total fraction of binaries/multiples in the sample with account for spectroscopic short-period systems and wide common proper motion pairs can be twice higher. The detected speckle components have a prominent peak in the ρ distribution that corresponds to the closest resolved pairs. Full version of present paper is available in electronic form at http://arxiv.org/abs/1308.3168.

scholarly journals Dynamo-generated magnetic fields in fast rotating single giants

2008 ◽  
Vol 4 (S259) ◽  
pp. 433-434 ◽  
Author(s):  
Renada Konstantinova-Antova ◽  
Michel Aurière ◽  
Klaus-Peter Schröder ◽  
Pascal Petit
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Stellar Evolution ◽  
Red Giants ◽  
Good Opportunity ◽  
Early Results ◽  
First Time ◽  
Fast Rotating

AbstractRed giants offer a good opportunity to study the interplay of magnetic fields and stellar evolution. Using the spectro-polarimeter NARVAL of the Telescope Bernard Lyot (TBL), Pic du Midi, France and the LSD technique we began a survey of magnetic fields in single G-K-M giants. Early results include 6 MF-detections with fast rotating giants, and for the first time a magnetic field was detected directly in an evolved M-giant: EK Boo. Our results could be explained in the terms of α–ω dynamo operating in these giants.

scholarly journals Magnetic Field Effect in the Process of Rinsing a Magnetic Separator Matrix

1988 ◽  
Vol 2 (3) ◽  
pp. 119-136
Author(s):  
Jiri Galas
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Circuit Design ◽  
Field Effect ◽  
Magnetic Circuit ◽  
Magnetic Field Effect ◽  
Magnetic Separator ◽  
High Gradient ◽  
First Time

This paper surveys fundamental aspects of the problem of rinsing matrices in high gradient magnetic separators. This is done, for the first time, in terms of the magnetic circuit design. Equations have been constructed to describe the effects of spurious remanent magnetic fields on the rinsing process.

scholarly journals Low-frequency pulsed electromagnetic field exposure can alter neuroprocessing in humans

2009 ◽  
Vol 7 (44) ◽  
pp. 467-473 ◽  
Author(s):  
John A. Robertson ◽  
Jean Théberge ◽  
Julie Weller ◽  
Dick J. Drost ◽  
Frank S. Prato ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Low Frequency ◽  
Imaging Study ◽  
Functional Brain Imaging ◽  
Anterior Cingulate ◽  
Detection Mechanism ◽  
Field Exposure ◽  
Thermal Pain ◽  
Pulsed Electromagnetic ◽  
First Time

Extremely low-frequency magnetic fields (from DC to 300 Hz) have been shown to affect pain sensitivity in snails, rodents and humans. Here, a functional magnetic resonance imaging study demonstrates how the neuromodulation effect of these magnetic fields influences the processing of acute thermal pain in normal volunteers. Significant interactions were found between pre- and post-exposure activation between the sham and exposed groups for the ipsilateral (right) insula, anterior cingulate and bilateral hippocampus/caudate areas. These results show, for the first time, that the neuromodulation induced by exposure to low-intensity low-frequency magnetic fields can be observed in humans using functional brain imaging and that the detection mechanism for these effects may be different from those used by animals for orientation and navigation. Magnetoreception may be more common than presently thought.

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