scholarly journals Secular polar motion observed by GRACE

2021 ◽  
Vol 95 (4) ◽  
Author(s):  
Ki-Weon Seo ◽  
Jae-Seung Kim ◽  
Kookhyoun Youm ◽  
Jianli Chen ◽  
Clark R. Wilson
Keyword(s):  
Climate Change ◽  
Twentieth Century ◽  
Polar Motion ◽  
Linear Trend ◽  
Surface Mass ◽  
Early Twentieth Century ◽  
Grace Data ◽  
Mass Load ◽  
The Difference ◽  
Mass Loads

AbstractA long-term drift in polar motion (PM) has been observed for more than a century, and Glacial Isostatic Adjustment (GIA) has been understood as an important cause. However, observed PM includes contributions from other sources, including contemporary climate change and perhaps others associated with Earth’s interior dynamics. It has been difficult to separate these effects, because there is considerable scatter among GIA models concerning predicted PM rates. Here we develop a new method to estimate GIA PM using data from the GRACE mission. Changes in GRACE degree 2, order 1 spherical harmonic coefficients are due both to GIA and contemporary surface mass load changes. We estimate the surface mass load contribution to degree 2, order 1 coefficients using GRACE data, relying on higher-degree GRACE coefficients that are dominantly affected by surface loads. Then the GIA PM trend is obtained from the difference between observed PM trend (which includes effects from GIA and surface mass loads) and the estimated PM trend mostly associated with surface mass loads. A previous estimate of the GIA PM trend from PM observations for the period 1900–1978 is toward 79.90° W at a speed of 3.53 mas/year (10.91 cm/year). Our new estimate for the GIA trend is in a direction of 61.77° W at a speed of 2.18 mas/year (6.74 cm/year), similar to the observed PM trend during the early twentieth century. This is consistent with the view that the early twentieth-century trend was dominated by GIA and that more recently there is an increasing contribution from contemporary surface mass load redistribution associated with climate change. Our GIA PM also agrees with the linear mean pole during 1900–2017. Contributions from other solid Earth process such as mantle convection would also produce a linear trend in PM and could be included in our GIA estimate.

The Sovereign Logic of Jack London’s Sea Stories

2017 ◽  
Author(s):  
Hank Scotch
Keyword(s):  
Twentieth Century ◽  
New World ◽  
World Order ◽  
The Self ◽  
New World Order ◽  
Early Twentieth Century ◽  
Spatial Differences ◽  
The Difference

Jack London’s maritime writing often interrogates the difference between the savage space of the “outside” sea and the relative domesticity of land’s civilized interior, as well as the ways in which this spatial distinction supports the sovereignty of space, society, and the self. But instead of maintaining these spatial differences, London’s work is all about exposing their increasing indistinction in the early twentieth century and the effects such a spatial destabilization had on sovereignty itself. This interrogation of the new world order and its effects on previous forms of sovereignty, the chapter argues, is what makes London’s contribution to American maritime writing (especially The Sea-Wolf and The Cruise of the Snark) so important. London’s sea stories not only acknowledge the world’s new “nomos” but the effects this order has on political and personal forms of autonomy and coherence.

Acoustic Tile as a mediating technology of organization

2019 ◽  
pp. 14-25
Author(s):  
Reinhold Martin
Keyword(s):  
Twentieth Century ◽  
Mechanical Systems ◽  
Early Twentieth Century ◽  
Organizational Effects ◽  
The Difference ◽  
Environmental Technologies

This chapter considers the history and organizational effects of the suspended acoustical tile ceiling in terms of the difference between ‘space’ (below) and ‘plenum’ (above). Reviewing the development of the acoustic tile since the early twentieth century, and the construction systems with which it was suspended to create a plenum between ceiling below and floor above, the chapter argues that this separation gave the ceiling new meaning. Increasingly, by isolating the mechanical hum of environmental technologies within the plenum, the suspended acoustical tile ceiling maintains a difference between the silence of ‘space’ and the noise of the mechanical systems that serve it.

The Influence of Early Twentieth-Century Technology

Jazz in China ◽  
2018 ◽  
pp. 21-31
Author(s):  
Eugene Marlow
Keyword(s):  
Twentieth Century ◽  
The Other ◽  
Early Twentieth Century ◽  
Communications Technologies ◽  
The World ◽  
The Difference ◽  
Music For Dance ◽  
Opium Wars

The superior war-making technology of the Western colonial powers—the steam-driven warship and cannon—made the difference between China prevailing and its defeat during the Opium Wars. It resulted in the colonial powers controlling Shanghai, tantamount to controlling China. In turn, the colonial powers brought their culture with them to Shanghai, which included jazz in the first quarter of the twentieth century. Within a couple of decades, jazz became not only the music of Shanghai but was global. This chapter asks how jazz traveled halfway around the world to China (and in the other direction, to Europe) so quickly? And how did the non-American musicians in Shanghai (Russians, Filipinos, and Chinese) learn to play the music for dance hall purposes? Transportation and communications technologies of the early twentieth century—the steamship, the locomotive, the gramophone, and early film—also were major influences in bringing jazz to China's shores.

The Brahmsian Hairpin

2012 ◽  
Vol 36 (1) ◽  
pp. 46-57 ◽  
Author(s):  
David Hyun-Su Kim
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Careful Examination ◽  
The Core ◽  
Early Twentieth Century ◽  
The Difference

Abstract Hairpins, the notation symbols < and >, are today universally accepted as equivalent to the markings crescendo and diminuendo, calling for an increase or decrease in volume. This view is irreconcilable with the scores of the core German repertoire of the nineteenth century. This article offers a new understanding of hairpins based on careful examination of the scores of Brahms and of early-twentieth-century recordings by artists close to him. In Brahms's milieu hairpins did not prescribe sounds, but rather described meanings. The difference between prescription and description is central, suggesting that instead of “growing louder/quieter,” hairpins are better understood as “becoming more/less.” The means by which “more/less” was realized by nineteenth-century musicians included many techniques beyond dynamics, most notably agogic inflection.

scholarly journals The Transformation of Historical Time: Processual and Evental Temporalities

2021 ◽  
Vol 31 (4) ◽  
pp. 219-246
Keyword(s):  
Climate Change ◽  
Artificial Intelligence ◽  
Twentieth Century ◽  
Philosophy Of History ◽  
Historical Time ◽  
The Past ◽  
The Future ◽  
Positive Meaning ◽  
The Difference ◽  
Modern Era

The author takes on two interrelated tasks. The first is to justify the philosophy of history as an intellectual enterprise for the modern era and one which is dedicated to finding a positive meaning in the changes that occur within humanity as it moves from the past toward the future. The viability of that enterprise has been called into question by the catastrophes of the twentieth century. The second task is to propose a new concept of historical temporality instead of the “processual” one that was discredited in the previous century. Simon maintains that we are now living in a period similar to the “saddle time” (from 1750 to 1850) described by Reinhart Koselleck. The difference between that period and the current one lies in the replacement of the “processual” temporality that was established in that earlier time by an “evental” temporality, whose structure this article is intended to explain. The future plays a key role in the structure of evental temporality. The future no longer denotes the perspective that maps out the direction of historical changes but is instead synonymous with changes as such — changes so radical that the continued existence of mankind within its former ecological, biological and physiological boundaries is at stake. The author illustrates these changes with references to bioengineering, artificial intelligence, anthropogenic climate change, etc. Expectations about these changes are utopian and dystopian at the same time and can feed one’s wildest hopes and fantasies as well as inspire the darkest fears and dreads. In any case, these changes themselves are in no way determined by the previous course of history. The future they point to undermines the continuity of human experience because it is completely independent of the past.

scholarly journals RHYTHM AND METRIC FEATURES OF YANKA KUPALA'S PRE-OCTOBER PERIOD POETRY

Keruen ◽  
2021 ◽  
Vol 70 (1) ◽  
Author(s):  
A. Aleychenko ◽  
◽  
Keyword(s):  
Twentieth Century ◽  
Organic Synthesis ◽  
Structural Characteristics ◽  
Semantic Role ◽  
Dimensional Approach ◽  
Objective Information ◽  
Systems Research ◽  
Early Twentieth Century ◽  
The Difference

The article deals with the research of Yanka Kupala's versification of the pre-October period in an integrated multi-dimensional approach. It is considered the difference of functional and structural characteristics of metric and rhythmic verse levels. It is identified the semantic role of rhythm-forming components and the semantic range of certain meters in Yanks Kupala's works. With the help of statistical and comparative-typological methods there are extracted the objective information about the rhythmic-metric features of the books «Zhaleyka», «Guslyar», «Slyasham zhyccia», traced the evolution of the creative heritage of the poet. It is dealt with the ways of the establishing of syllabic and accentual verse principles in Belarusian poetry of the early twentieth century by Yanka Kupala, as well as the objective laws of the organic synthesis of syllabic-tonic and tonic verse systems. Research prepares materials for creation of directory poetic dimensions of the creative heritage of the poet, theoretical and practical course on Yanka Kupala's versification, the same way as a relevant monographic studies.

scholarly journals Modern changes of the runoff characteristics of the rivers of the Greater Caucasus

2020 ◽  
pp. 26-33
Author(s):  
Irada S. Aliyeva
Keyword(s):  
Climate Change ◽  
Surface Runoff ◽  
River Flow ◽  
Linear Trend ◽  
Winter Season ◽  
Annual Runoff ◽  
Arithmetic Average ◽  
Greater Caucasus ◽  
The Difference ◽  
Underground Flow

The article is devoted to the analysis of modern changes in annual runoff, its main components – underground and surface runoff, as well as the minimum winter and summer-autumn runoff rivers of the Greater Caucasus within Azerbaijan. A brief review of previous studies on flow changes in the country is given. It is noted that in these works the method of geographical comparison and linear trend analysis were used. It is concluded that the changes in the surface and under ground runoff of the rivers of the Greater Caucasus due to climate change have not yet been analysed. The data on the runoff of 17 hydrological observation points covering 1934–2017 were analysed. All these hydrological observation points are located in the mountainous part of the river basins, i. e. runoff indices characterise the natural or conditionally natural regime of rivers. The annual values of the underground flow were determined as the arithmetic average of the monthly average minimum winter and summer-autumn water discharges. The annual values of surface runoff are calculated as the difference between annual and underground runoff. The method of geographical comparison is used. Calculations and generalisations of the results obtained are performed for different periods, according to the recommendations of the World Meteorological Organisation. It was revealed that, for 1981–2010 and 2001–2017 surface runoff of the rivers of the studied region decreased compared to runoff for the base period (1961–1990), due to a decrease in the amount of snow precipitation and a decrease in the volume of spring flood. However, there was a more significant increase in the underground flow of rivers and, therefore, an increase in annual flow was observed throughout the region. The dynamics of changes in the minimum river flow, especially in the winter season, is also positive, since over the past decades the snow cover has been melting earlier than usual, and favorable conditions are being created for the formation of groundwater that feeds the rivers during periods of minimal runoff. It is noted that the revealed nature of changes in various indices of river flow in the studied region is associated with climate change.

scholarly journals Constrained Linear Deconvolution of GRACE Anomalies to Correct Spatial Leakage

2020 ◽  
Vol 12 (11) ◽  
pp. 1798
Author(s):  
Ki-Weon Seo ◽  
Seokhoon Oh ◽  
Jooyoung Eom ◽  
Jianli Chen ◽  
Clark R. Wilson
Keyword(s):  
Climate Forcing ◽  
Mass Change ◽  
Data Types ◽  
Surface Mass ◽  
Grace Data ◽  
Mass Redistribution ◽  
Grace Satellites ◽  
Earth’S Climate ◽  
Gravity Recovery ◽  
Mass Loads

Time-varying gravity observed by the Gravity Recovery and Climate Experiment (GRACE) satellites measures surface water and ice mass redistribution driven by weather and climate forcing and has emerged as one of the most important data types in measuring changes in Earth’s climate. However, spatial leakage of GRACE signals, especially in coastal areas, has been a recognized limitation in quantitatively assessing mass change. It is evident that larger terrestrial signals in coastal regions spread into the oceans and vice versa and various remedies have been developed to address this problem. An especially successful one has been Forward Modeling but it requires knowledge of geographical locations of mass change to be fully effective. In this study, we develop a new method to suppress leakage effects using a linear least squares operator applied to GRACE spherical harmonic data. The method is effectively a constrained deconvolution of smoothing inherent in GRACE data. It assumes that oceanic mass changes near the coast are negligible compared to terrestrial changes, with additional spatial regularization constraints. Some calibration of constraint weighting is required. We apply the method to estimate surface mass loads over Australia using both synthetic and real GRACE data. Leakage into the oceans is effectively suppressed and when compared with mascon solutions there is better performance over interior basins.

Some Polish Composers of To-Day

Tempo ◽  
1948 ◽  
pp. 25-28
Author(s):  
Andrzej Panufnik
Keyword(s):  
Twentieth Century ◽  
Fertile Soil ◽  
Early Twentieth Century ◽  
Progressive Group ◽  
Karol Szymanowski

It is ten years since KAROL SZYMANOWSKI died at fifty-four. He was the most prominent representative of the “radical progressive” group of early twentieth century composers, which we call “Young Poland.” In their manysided and pioneering efforts they prepared the fertile soil on which Poland's present day's music thrives.

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