scholarly journals Triple-Pair Constellation Configurations for Temporal Gravity Field Retrieval

2020 ◽  
Vol 12 (5) ◽  
pp. 831 ◽  
Author(s):  
Anna F. Purkhauser ◽  
Roland Pail
Keyword(s):  
Spherical Harmonic Degree ◽  
The Third ◽  
The Earth ◽  
Average Improvement ◽  
Gravity Fields ◽  
New Generation ◽  
The Impact ◽  
Temporal Gravity ◽  
Harmonic Degree ◽  
Additional Constraints

The goal of next-generation gravity missions (NGGM) is to improve the monitoring of mass transport in the Earth system by an increased space-time sampling capability as well as higher accuracies of a new generation of instrumentation, but also to continue the monitoring time series obtained by past and current missions such as GRACE and GRACE Follow-On. As the likelihood of three satellite pairs being simultaneously in orbit in the mid-term future increased, we have performed a closed-loop simulation to investigate the impact of a third pair in either polar or inclined orbit as an addition to a Bender-type constellation with NGGM instrumentation. For the additional pair, GRACE-like as well as NGGM instrumentation was tested. The analysis showed that the third pair mainly increases the redundancy of the monitoring system but does not significantly improve de-aliasing capabilities. The best-performing triple-pair scenario comprises a third inclined pair with NGGM sensors. Starting with a Bender-type constellation of a polar and an inclined satellite pair, simulation results indicate an average improvement of 11% in case of adding the third pair in a near-polar orbit, and of 21% for the third pair placed in an inclined orbit. The most important advantage of a multi-pair constellation, however, is the possibility to recover daily gravity fields with higher spatial resolution. In the case of the investigated triple-pair scenarios, a meaningful daily resolution with a maximum spherical harmonic degree of 26 can be achieved, while a higher daily parametrization up to degree 40 results in spatial aliasing and thus would need additional constraints or prior information.

scholarly journals Linking zonal winds and gravity: the relative importance of dynamic self-gravity

2020 ◽  
Vol 492 (3) ◽  
pp. 3364-3374 ◽  
Author(s):  
Johannes Wicht ◽  
Wieland Dietrich ◽  
Paula Wulff ◽  
Ulrich R Christensen
Keyword(s):  
Zonal Flow ◽  
Order Effect ◽  
Radial Dependence ◽  
Spherical Harmonic Degree ◽  
Zonal Flows ◽  
Gravity Fields ◽  
Gravity Measurements ◽  
Density Perturbations ◽  
Self Gravity ◽  
The Impact

ABSTRACT Recent precise measurements of Jupiter’s and Saturn’s gravity fields help constraining the properties of the zonal flows in the outer envelopes of these planets. The link is provided by a simplified dynamic equation, which connects zonal flows to related buoyancy perturbations. These can result from density perturbations but also from the gravity perturbations. Whether the latter effect, which we call dynamic self-gravity (DSG), must be included or is negligible has been a matter of intense debate. We show that the second-order differential equation for the gravity perturbations becomes an inhomogeneous Helmholtz equation when assuming a polytrope of index unity for density and pressure. This equation can be solved semi-analytically when using modified spherical Bessel functions for describing the radial dependence. The respective solutions allow us to quantify the impact of the DSG on each gravity harmonic, practically independent of the zonal flow or the details of the planetary interior model. We find that the impact decreases with growing spherical harmonic degree ℓ. For degrees ℓ = 2 to about ℓ = 4, the DSG is a first-order effect and should be taken into account in any attempt of inverting gravity measurements for zonal flow properties. For degrees of about ℓ = 5 to roughly ℓ = 10, the relative impact of DSG is about 10 per cent and thus seems worthwhile to include, in particular since this comes at little extra cost with the method presented here. For yet higher degrees, it seems questionable whether gravity measurements or interior models will ever reach the precision required for disentangling the small DSG effects, which amount to only a few per cent at best.

scholarly journals Introduction to the ringing effect in satellite hyperspectral atmospheric spectrometry

2021 ◽  
Author(s):  
Pierre Dussarrat ◽  
Bertrand Theodore ◽  
Dorothee Coppens ◽  
Carsten Standfuss ◽  
Bernard Tournier
Keyword(s):  
Fourier Transform ◽  
Weather Prediction ◽  
Atmospheric Composition ◽  
The Earth ◽  
New Generation ◽  
Ringing Effect ◽  
The Impact ◽  
Composition Monitoring ◽  
Remote Spectrometry ◽  
Intrinsic Feature

Abstract. Atmospheric remote spectrometry from space has become in the last 20 years a key component of the Earth monitoring system: their large coverage and deci-kelvin stability have demonstrated their usefulness for weather prediction, atmospheric composition monitoring as well as climate monitoring. It is thus critical to investigate the possible sources of errors associated to this technique. One of them is the so-called "ringing error" that appears in Fourier transform spectrometers when the instrument transmission varies at the scale of the spectral resolution. This paper exposes the theoretical basis of this particular type of radiometric uncertainty. Its sensitivity to instrumental parameters as well as the impact on the radiometrically calibrated measurements is assessed in the context of atmospheric infrared sounding using Fourier transform spectrometers. It is shown that this error is an intrinsic feature of such instruments that could safely be ignored in early-generation instruments but will have to be taken into account in the new generation ones as it can yield a significant degradation of the radiometric error budget.

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.

Overcoming stereotypes of renewable energy

2019 ◽  
pp. 124-136
Author(s):  
Victor D. Gazman
Keyword(s):  
Renewable Energy ◽  
Empirical Analysis ◽  
Energy Generation ◽  
New Paradigm ◽  
Financial Instrument ◽  
Promising Direction ◽  
Investment Projects ◽  
Power Stations ◽  
New Generation ◽  
The Impact

The article considers prerequisites for the formation of a new paradigm in the energy sector. The factors that may affect the imminent change of leadership among the energy generation are analyzed. The variability of the projects of creation and functioning of power stations is examined. The focus is made on problematic aspects of the new generation, especially, storage and supply of energy, achieving a system of parity that ensures balance in pricing generations. The author substantiates the principles of forming system of parities arising when comparing traditional and new generations. The article presents the results of an empirical analysis of the 215 projects for the construction of facilities for renewable energy. The significance and direction of the impact of these factors on the growth in investment volumes of transactions are determined. The author considers leasing as an effective financial instrument for overcoming stereotypes of renewable energy and as a promising direction for accelerated implementation of investment projects.

Social and political dimension of stigmatization: The development of Natasha and Maria images for immigrants in Istanbul

2016 ◽  
Vol 13 (1) ◽  
pp. 159-168
Author(s):  
Bayram Unal
Keyword(s):  
Public Perception ◽  
Daily Life ◽  
Legal Framework ◽  
State Law ◽  
Migrant Women ◽  
Political Dimension ◽  
Security Forces ◽  
Official Discourse ◽  
The Third ◽  
The Impact

This study aims at understanding how the perceptions about migrants have been created and transferred into daily life as a stigmatization by means of public perception, media and state law implementations.  The focus would be briefly what kind of consequences these perceptions and stigmatization might lead. First section will examine the background of migration to Turkey briefly and make a summary of migration towards Turkey by 90s. Second section will briefly evaluate the preferential legal framework, which constitutes the base for official discourse differentiating the migrants and implementations of security forces that can be described as discriminatory. The third section deals with the impact of perceptions influential in both formation and reproduction of inclusive and exclusive practices towards migrant women. Additionally, impact of public perception in classifying the migrants and migratory processes would be dealt in this section.

Pèlerinages barrésiens

2013 ◽  
pp. 116-123
Author(s):  
Claire Bompaire-Evesque
Keyword(s):  
Large Scale ◽  
The Self ◽  
Joan Of Arc ◽  
The Third ◽  
National Importance ◽  
The Earth ◽  
Third Stage ◽  
The Dead

This article is a inquiry about how Barrès (1862-1923) handles the religious rite of pilgrimage. Barrès stages in his writings three successive forms of pilgrimage, revealing what is sacred to him at different times. The pilgrimage to a museum or to the birthplace of an artist is typical for the egotism and the humanism of the young Barrès, expressed in the Cult of the Self (1888-1891). After his conversion to nationalism, Barrès tries to unite the sons of France and to instill in them a solemn reverence for “the earth and the dead” ; for that purpose he encourages in French Amities (1903) pilgrimages to historical places of national importance (battlefields; birthplace of Joan of Arc), building what Nora later called the Realms of Memory. The third stage of Barrès’ intellectual evolution is exemplified by The Sacred Hill (1913). In this book the writer celebrates the places where “the Spirit blows”, and proves open to a large scale of spiritual forces, reaching back to paganism and forward to integrative syncretism, which aims at unifying “the entire realm of the sacred”.

The impact of maternal obesity on fetal adiposity in the third trimester

2010 ◽  
Vol 95 (Supplement 1) ◽  
pp. Fa25-Fa25
Author(s):  
N. Farah ◽  
M. Kennelly ◽  
V. Donnelly ◽  
B. Stuart ◽  
M. Turner
Keyword(s):  
Maternal Obesity ◽  
Third Trimester ◽  
The Third ◽  
The Impact

Law and Economics

2020 ◽  
pp. 84-102
Author(s):  
Daniel B. Kelly
Keyword(s):  
Economic Analysis ◽  
First Generation ◽  
Law And Economics ◽  
Private Law ◽  
Foreseeable Future ◽  
Business Associations ◽  
The Third ◽  
Starting Point ◽  
The Law ◽  
The Impact

This chapter analyzes how law and economics influences private law and how (new) private law is influencing law and economics. It focuses on three generation or “waves” within law and economics and how they approach private law. In the first generation, many scholars took the law as a starting point and attempted to use economic insights to explain, justify, or reform legal doctrines, institutions, and structures. In the second generation, the “law” at times became secondary, with more focus on theory and less focus on doctrines, institutions, and structures. But this generation also relied increasingly on empirical analysis. In the third generation, which includes scholars in the New Private Law (NPL), there has been a resurgence of interest in the law and legal institutions. To be sure, NPL scholars analyze the law using various approaches, with some more and some less predisposed to economic analysis. However, economic analysis will continue to be a major force on private law, including the New Private Law, for the foreseeable future. The chapter considers three foundational private law areas: property, contracts, and torts. For each area, it discusses the major ideas that economic analysis has contributed to private law, and surveys contributions of the NPL. The chapter also looks at the impact of law and economics on advanced private law areas, such as business associations, trusts and estates, and intellectual property.

Of numbers, narratives and challenges: Data as evidence in 21st century policy-making

2020 ◽  
Vol 36 (4) ◽  
pp. 1043-1055
Author(s):  
Gaby Umbach
Keyword(s):  
21St Century ◽  
Policy Making ◽  
Evidence Use ◽  
The Third ◽  
Use Of Data ◽  
Science Advice ◽  
Governance Tools ◽  
The Impact

This article1 offers reflections on the use of data as evidence in 21st century policy-making. It discusses the concept of evidence-informed policy-making (EIPM) as well as the governance and knowledge effects of data as evidence. With this focus, it interlinks the analysis of statistics and politics. The paper first introduces the concept of EIPM and the impact of evidence use. Here it focusses on science and knowledge as resources in policy-making, on the institutionalisation of science advice and on the translation of information and knowledge into evidence. The second part of the article reflects on data as evidence. This part concentrates on abstract and concrete functions of data as governance tools in policy-making, on data as a robust form of evidence and on the effects of data on knowledge and governance. The third part highlights challenges for data as evidence in policy-making, among them, politicisation, transparency, and diversity as well as objectivity and contestation. Finally, the last part draws conclusions on the production and use of data as evidence in EIPM. Throughout the second part of the reflections, reference is made to Walter Radermacher’s 2019 matrix of actors and activities related to data, facts, and policy published in this journal.

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