Observations of the Infrared Outgoing Spectrum of the Earth from Space: The Effects of Temporal and Spatial Sampling

2003 ◽  
Vol 16 (22) ◽  
pp. 3820-3833 ◽  
Author(s):  
H. E. Brindley ◽  
J. E. Harries
Keyword(s):  
Spatial Sampling ◽  
The Earth ◽  
Temporal And Spatial

scholarly journals Sequential modelling of the Earth’s core magnetic field

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Guillaume Ropp ◽  
Vincent Lesur ◽  
Julien Baerenzung ◽  
Matthias Holschneider
Keyword(s):  
Magnetic Field ◽  
Prior Information ◽  
Spatial Scales ◽  
Model Parameters ◽  
International Geomagnetic Reference Field ◽  
The Earth ◽  
Temporal And Spatial ◽  
Different Sources ◽  
Original Approach ◽  
Modelling Approach

Abstract We describe a new, original approach to the modelling of the Earth’s magnetic field. The overall objective of this study is to reliably render fast variations of the core field and its secular variation. This method combines a sequential modelling approach, a Kalman filter, and a correlation-based modelling step. Sources that most significantly contribute to the field measured at the surface of the Earth are modelled. Their separation is based on strong prior information on their spatial and temporal behaviours. We obtain a time series of model distributions which display behaviours similar to those of recent models based on more classic approaches, particularly at large temporal and spatial scales. Interesting new features and periodicities are visible in our models at smaller time and spatial scales. An important aspect of our method is to yield reliable error bars for all model parameters. These errors, however, are only as reliable as the description of the different sources and the prior information used are realistic. Finally, we used a slightly different version of our method to produce candidate models for the thirteenth edition of the International Geomagnetic Reference Field.

Benchmarking GPS stations: an improved way to identify the GPS sensitivity

2021 ◽  
Author(s):  
Anna Klos ◽  
Jürgen Kusche ◽  
Artur Lenczuk ◽  
Grzegorz Leszczuk ◽  
Janusz Bogusz
Keyword(s):  
Time Series ◽  
Global Positioning System ◽  
Spatial Density ◽  
Earth System ◽  
Global Networks ◽  
The Earth ◽  
Mass Redistribution ◽  
Wide Range ◽  
Global Positioning ◽  
Temporal And Spatial

<p>Global Positioning System (GPS) stations are affected by a plethora of real and system-related signals and errors that occur at various temporal and spatial resolutions. Geophysical changes related to mass redistribution within the Earth system, common mode components, instability of GPS monuments or thermal expansion of ground, all contribute to the GPS-derived displacement time series. Different spatial resolutions that real and system-related errors occur within are covered thanks to the global networks of GPS stations, characterized presently by an unprecedented spatial density. Various temporal resolutions are covered by displacement time series which span even 25 years now, as estimated for the very first stations established. However, since the GPS sensitivity remains unrecognized, retrieving one signal from this wide range of processes may be very uncertain. Up to now, a comparison between GPS-observed displacement time series and displacements predicted by a set of models, as e.g. environmental loading models, was used to demonstrate the accuracy of the model to predict the observed phenomena. Such a comparison is, however, dependent on the accuracy of models and also on the sensitivity of individual GPS stations. We present a new way to identify the GPS sensitivity, which is based on benchmarking of individual GPS stations using statistical clustering approaches. We focus on regional sets of GPS stations located in Europe, where technique-related signals cover real geophysical changes for many GPS permanent stations and those located in South America and Asia, where hydrological and atmospheric loadings dominate other effects. We prove that combining GPS stations into smaller sets improves our understanding of real and system-related signals and errors.</p>

An overview of the plumbing systems of Large Igneous Provinces and their significance

2021 ◽  
pp. SP518-2021-167
Author(s):  
Rajesh K. Srivastava ◽  
Richard E. Ernst ◽  
Kenneth L. Buchan ◽  
Michiel de Kock
Keyword(s):  
Mass Extinctions ◽  
Base Metals ◽  
Temporal And Spatial Distribution ◽  
The Earth ◽  
New Information ◽  
Igneous Provinces ◽  
Wide Range ◽  
Plumbing Systems ◽  
Temporal And Spatial ◽  
Dyke Swarms

AbstractIdentification of large volume, short duration mafic magmatic events of intraplate affinity in both continental and oceanic settings on the Earth and other planets provides invaluable clues for understanding several vital geological issues of current concern. Of particular importance is understanding the assembly and dispersal of supercontinents through Earth's history, dramatic climate change events including mass extinctions, and processes that have produced a wide range of LIP-related resources such as Ni-Cu-PGE, Au, U, base metals, and petroleum. This current volume presents some of the latest developments and new information on the temporal and spatial distribution of LIPs in both the Precambrian and Phanerozoic, their origin, the plumbing system of mafic dyke swarms, sill provinces, and layered inrusions, and links to mantle plumes/superplumes events, supercontinent reconstructions and associated metallogeny.

scholarly journals Triggering of twists in solar prominence threads

2019 ◽  
Vol 631 ◽  
pp. A144 ◽  
Author(s):  
Y. Taroyan ◽  
R. Soler
Keyword(s):  
Equations Of Motion ◽  
Solar Prominence ◽  
Governing Equations ◽  
Evaporation And Condensation ◽  
The Earth ◽  
Solar Prominences ◽  
Amplification Process ◽  
Converging Flow ◽  
Temporal And Spatial ◽  
Generation Of Vortices

Context. Magnetic twists are commonly associated with solar prominences. Twists are believed to play an important role in supporting the dense plasma against gravity as well as in prominence eruptions and coronal mass ejections, which may have a severe impact on the Earth and its near environment. Aims. We used a simple model to mimic the formation of a prominence thread by plasma condensation with the aim of investigating the possibility of triggering twists during this process. Methods. Temporal and spatial evolution of torsional Alfvénic perturbations driven by random photospheric motions was analysed using the linearised governing equations of motion and induction. Results. We find that small amplitude perturbations are exponentially amplified in time as they propagate along the condensing thread. Mechanisms contributing to the rapid growth are explored. The result of the amplification process is the generation of large amplitude axisymmetric twists along the thread. Conclusions. Magnetic twists may be triggered along a prominence thread when it is permeated by a converging flow, for example, during the evaporation and condensation of plasma along the thread. This may lead to the generation of vortices in the non-linear regime.

scholarly journals Flux emergence event underneath a filament

2014 ◽  
Vol 10 (S305) ◽  
pp. 79-85
Author(s):  
J. Palacios ◽  
Y. Cerrato ◽  
C. Cid ◽  
A. Guerrero ◽  
E. Saiz
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Spatial Scales ◽  
Transverse Field ◽  
Magnetic Flux Density ◽  
Flux Emergence ◽  
Filament Eruption ◽  
The Earth ◽  
Temporal And Spatial ◽  
Emergence Event

AbstractFlux emergence phenomena are relevant at different temporal and spatial scales. We have studied a flux emergence region underneath a filament. This filament elevated itself smoothly, and the associated CME reached the Earth. In this study we investigate the size and the amount of flux in the emergence event. The flux emergence site appeared just beneath a filament. The emergence acquired a size of 24 Mm in half a day. The unsigned magnetic flux density from LOS-magnetograms was around 1 kG at its maximum. The transverse field as well as the filament eruption were also analysed.

scholarly journals Sequential modelling of the Earth's core magnetic field

2020 ◽  
Author(s):  
Guillaume Ropp ◽  
Vincent Lesur ◽  
Julien Baerenzung ◽  
Matthias Holschneider
Keyword(s):  
Magnetic Field ◽  
Prior Information ◽  
Spatial Scales ◽  
Model Parameters ◽  
The Core ◽  
The Earth ◽  
Temporal And Spatial ◽  
Different Sources ◽  
Original Approach ◽  
Modelling Approach

Abstract We describe a new, original approach to the modelling of the Earth's magnetic field. The overall objective of this study is to reliably render fast variations of the core field and its secular variation. This method combines a sequential modelling approach, a Kalman filter, and a correlation based modelling step. All sources that most significantly contribute to the field measured at the surface of the Earth are modelled. Their separation is based on strong prior information on their spatial and temporal behaviours. We obtain a time series of model distributions which display behaviours similar to those of recent models based on more classic approaches, particularly at large temporal and spatial scales. Interesting new features and periodicities are visible in our models at smaller time and spatial scales. An important aspect of our method is to yield reliable error bars for all model parameters. These errors, however, are only as reliable as the description of the different sources and the prior information used are realistic. Finally, we used a slightly different version of our method to produce candidate models for the IGRF-13.

scholarly journals TOWARDS THE IMPLEMENTATION OF SEMI-DYNAMIC DATUM FOR MALAYSIA

2017 ◽  
Vol XLII-4/W5 ◽  
pp. 185-199
Author(s):  
N. S. Shariff ◽  
J. Gill ◽  
Z. M. Amin ◽  
K. M. Omar
Keyword(s):  
Seismic Activity ◽  
Interpolation Method ◽  
Bilinear Interpolation ◽  
Complex Deformation ◽  
The Past ◽  
The Earth ◽  
Time Series Analyses ◽  
Temporal And Spatial ◽  
Deformation Models ◽  
Gps Time Series

A semi-dynamic datum provides positions with respect to time while taking into account the secular and non-secular deformations, making it the best approach to adapt with the dynamic processes of the earth. Malaysia, as yet, employs a static datum, i.e., GDM2000, at epoch 2000; though Malaysia has evidently been affected by seismic activity for the past decade. Therefore, this paper seeks to propose a design for implementing a semi-dynamic datum for Malaysia. Methodologically, GPS time series analyses are carried out to investigate the seismic activity of Malaysia, which essentially contributes to the proposed design of the semi-dynamic datum for Malaysia. The implications of implementing a semi-dynamic datum for Malaysia are discussed as well. The results indicate that Malaysia undergoes a complex deformation; whereby the earthquakes – primarily the 2004 Sumatra-Andaman, 2005 Nias and 2012 Northern Sumatra earthquakes – have affected the underlying secular velocities of Malaysia. Consequently, from this information, the proposed design, particularly the secular and non-secular deformation models, is described in detail. The proposed semi-dynamic datum comprises a transformation, temporal, and spatial module, and utilizes a bilinear interpolation method. Overall, this paper aims to contribute to the feasibility of a semi-dynamic datum approach for Malaysia.

Agriculture and Land Transformation. 1. Temporal and Spatial Dimensions

1997 ◽  
Vol 26 (2) ◽  
pp. 71-78 ◽  
Author(s):  
Antoinette M. Mannion
Keyword(s):  
Cultural History ◽  
Scientific Development ◽  
World Population ◽  
Land Transformation ◽  
The Earth ◽  
The World ◽  
Spatial Dimensions ◽  
The Face ◽  
Temporal And Spatial

Ever since it began 10,000 years ago, agriculture has been a major cause of land transformation. It has been the basis on which civilizations have waxed and waned, it has allowed the world population to reach 5 × 109 and it has profoundly influenced cultural and scientific development. While its inception was itself momentous in terms of environmental and cultural history, the changes in agriculture caused by the expansion of Europe between 1500 and 1900 had equally profound ramifications. These developments literally changed the face of the earth. This paper surveys the changes that have taken place so far, while Part 2, to appear in the next issue, looks at likely future patterns.

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