scholarly journals Changes in the strength and width of the Hadley Circulation since 1871

2012 ◽  
Vol 8 (4) ◽  
pp. 1169-1175 ◽  
Author(s):  
J. Liu ◽  
M. Song ◽  
Y. Hu ◽  
X. Ren
Keyword(s):  
20Th Century ◽  
Global Climate ◽  
Hadley Circulation ◽  
Recent Change ◽  
Early 20Th Century ◽  
Greenhouse Warming ◽  
Long Period ◽  
The Past ◽  
Period Oscillation

Abstract. Recent studies demonstrate that the Hadley Circulation has intensified and expanded for the past three decades, which has important implications for subtropical societies and may lead to profound changes in global climate. However, the robustness of this intensification and expansion that should be considered when interpreting long-term changes of the Hadley Circulation is still a matter of debate. It also remains largely unknown how the Hadley Circulation has evolved over longer periods. Here, we present long-term variability of the Hadley Circulation using the 20th Century Reanalysis. It shows a slight strengthening and widening of the Hadley Circulation since the late 1970s, which is not inconsistent with recent assessments. However, over centennial timescales (1871–2008), the Hadley Circulation shows a tendency towards a more intense and narrower state. More importantly, the width of the Hadley Circulation might have not yet completed a life-cycle since 1871. The strength and width of the Hadley Circulation during the late 19th to early 20th century show strong natural variability, exceeding variability that coincides with global warming in recent decades. These findings raise the question of whether the recent change in the Hadley Circulation is primarily attributed to greenhouse warming or to a long-period oscillation of the Hadley Circulation – substantially longer than that observed in previous studies.

scholarly journals Changes in the strength and width of the Hadley circulation since 1871

2012 ◽  
Vol 8 (2) ◽  
pp. 695-713 ◽  
Author(s):  
J. Liu ◽  
M. Song ◽  
Y. Hu ◽  
X. Ren
Keyword(s):  
20Th Century ◽  
Global Climate ◽  
Hadley Circulation ◽  
Recent Change ◽  
Early 20Th Century ◽  
Greenhouse Warming ◽  
Long Period ◽  
The Past ◽  
Period Oscillation

Abstract. Recent studies demonstrate that the Hadley Circulation has intensified and expanded for the past three decades, which has important implications for subtropical societies and may lead to profound changes in global climate. However, the robustness of this intensification and expansion that should be considered when interpreting long-term changes of the Hadley Circulation is still matters of debate. It also remains largely unknown how the Hadley Circulation has evolved over longer periods. Here we present long-term variability of the Hadley Circulation using the 20th Century Reanalysis. It shows a slight strengthening and widening of the Hadley Circulation since the late 1970s, which is not inconsistent with recent assessments. However, over centennial timescales (1871–2008), the Hadley Circulation shows a tendency towards more intense and narrower state. More importantly, the width of the Hadley Circulation has not yet completed a life-cycle since 1871. The strength and width of the Hadley Circulation during the late 19th and early 20th century show strong natural variability, exceeding variability that coincides with global warming in recent decades. These findings raise the question that the recent change of the Hadley Circulation is primarily attributed to greenhouse warming or a long-period oscillation of the Hadley Circulation substantially longer than that observed in previous studies.

scholarly journals Global climatology and trends in convective environments from ERA5 and rawinsonde data

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mateusz Taszarek ◽  
John T. Allen ◽  
Mattia Marchio ◽  
Harold E. Brooks
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Global Climate ◽  
Convective Available Potential Energy ◽  
Global Climate Models ◽  
Convective Precipitation ◽  
The Past ◽  
The Tropics ◽  
Rawinsonde Data

AbstractGlobally, thunderstorms are responsible for a significant fraction of rainfall, and in the mid-latitudes often produce extreme weather, including large hail, tornadoes and damaging winds. Despite this importance, how the global frequency of thunderstorms and their accompanying hazards has changed over the past 4 decades remains unclear. Large-scale diagnostics applied to global climate models have suggested that the frequency of thunderstorms and their intensity is likely to increase in the future. Here, we show that according to ERA5 convective available potential energy (CAPE) and convective precipitation (CP) have decreased over the tropics and subtropics with simultaneous increases in 0–6 km wind shear (BS06). Conversely, rawinsonde observations paint a different picture across the mid-latitudes with increasing CAPE and significant decreases to BS06. Differing trends and disagreement between ERA5 and rawinsondes observed over some regions suggest that results should be interpreted with caution, especially for CAPE and CP across tropics where uncertainty is the highest and reliable long-term rawinsonde observations are missing.

scholarly journals Lviv as the cradle of Polish independence organizations

2021 ◽  
Vol 201 (3) ◽  
pp. 534-545
Author(s):  
Janusz Zuziak
Keyword(s):  
Twentieth Century ◽  
20Th Century ◽  
Early 20Th Century ◽  
Social Activists ◽  
The Past ◽  
Independence Movement ◽  
Political Orientations ◽  
History Of ◽  
The Right ◽  
The City

Lviv occupies a special place in the history of Poland. With its heroic history, it has earned the exceptionally honorable name of a city that has always been faithful to the homeland. SEMPER FIDELIS – always faithful. Marshal Józef Piłsudski sealed that title while decorating the city with the Order of Virtuti Militari in 1920. The past of Lviv, the always smoldering and uncompromising Polish revolutionist spirit, the climate, and the atmosphere that prevailed in it created the right conditions for making it the center of thought and independence movement in the early 20th century. In the early twentieth century, Polish independence organizations of various political orientations were established, from the ranks of which came legions of prominent Polish politicians and military and social activists.

A North American Historical Review of Three-Axle Freight Trucks

2020 ◽  
Author(s):  
William Shust ◽  
Michael M. Palmieri
Keyword(s):  
20Th Century ◽  
North American ◽  
Historical Review ◽  
Early 20Th Century ◽  
Past Century ◽  
Heavy Duty ◽  
The Past ◽  
American Historical Review ◽  
Current Usage ◽  
Freight Trucks

Abstract At first glance, it seems appealing to suggest additional wheelsets under a given railcar type. From the track’s viewpoint, and in a simplistic analysis, trading a particular car’s four-axles for the use of six should allow half again more car weight. This paper will examine efforts to test this concept over the past century. Indeed, the railway marketplace has investigated the three-axle truck in both the freight and passenger car arenas multiple times over the past century. Except in heavy-duty flatcars, the record shows that each implementation has proven to be only temporary. In general, three-axle freight trucks were developed for use with steam locomotive tenders in the early 20th century. These designs were then adapted to other car types over several decades, involving thousands of individual cars. Today, three-axle trucks are nearly extinct. This paper will address the history and status of three-axle freight trucks (or bogies) as used in North American railcar operations. Various past 20th-century applications will be discussed. International efforts will be reviewed as well. The very limited and remaining current usage of three-axle trucks is also discussed.

scholarly journals 20th-century sea-ice variations from observational data

2001 ◽  
Vol 33 ◽  
pp. 444-448 ◽  
Author(s):  
John E. Walsh ◽  
William L. Chapman
Keyword(s):  
Sea Ice ◽  
20Th Century ◽  
North Atlantic ◽  
Climate Models ◽  
Global Climate ◽  
Arctic Sea Ice ◽  
Empirical Orthogonal Functions ◽  
Global Climate Models ◽  
The Past ◽  
Ice Coverage

AbstractIn order to extend diagnoses of recent sea-ice variations beyond the past few decades, a century-scale digital dataset of Arctic sea-ice coverage has been compiled. For recent decades, the compilation utilizes satellite-derived hemispheric datasets. Regional datasets based primarily on ship reports and aerial reconnaissance are the primary inputs for the earlier part of the 20th century. While the various datasets contain some discrepancies, they capture the same general variations during their period of overlap. The outstanding feature of the time series of total hemispheric ice extent is a decrease that has accelerated during the past several decades. The decrease is greatest in summer and weakest in winter, contrary to the seasonality of the greenhouse changes projected by most global climate models. The primary spatial modes of sea-ice variability diagnosed in terms of empirical orthogonal functions, also show a strong seasonality. The first winter mode is dominated by an opposition of anomalies in the western and eastern North Atlantic, corresponding to the well-documented North Atlantic Oscillation. The primary summer mode depicts an anomaly of the same sign over nearly the entire Arctic and captures the recent trend of sea-ice coverage.

Trends in the frequency, extent, and severity of spruce budworm outbreaks in eastern Canada

1983 ◽  
Vol 13 (4) ◽  
pp. 539-547 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
20Th Century ◽  
Large Scale ◽  
Spruce Budworm ◽  
Forest Composition ◽  
Eastern Canada ◽  
Clear Cutting ◽  
The Past ◽  
Spruce Stands ◽  
History Of

The history of spruce budworm (Choristoneurafumiferana (Clem.)) outbreaks for the past 200 to 300 years, for nine regions in eastern Canada, indicates that outbreaks have occurred more frequently in the 20th century than previously. Regionally, 21 outbreaks took place in the past 80 years compared with 9 in the preceding 100 years. Earlier infestations were restricted to specific regions, but in the 20th century they have coalesced and increased in size, the outbreaks of 1910, 1940, and 1970 having covered 10, 25, and 55 million ha respectively. Reasons for the increase in frequency, extent, and severity of outbreaks appear mostly attributable to changes caused by man, in the forest ecosystem. Clear-cutting of pulpwood stands, fire protection, and use of pesticides against budworm favor fir–spruce stands, rendering the forest more prone to budworm attack. The manner and degree to which each of these practices has altered forest composition is discussed. In the future, most of these practices are expected to continue and their effects could intensify, especially in regions of recent application. Other practices, including large-scale planting of white spruce, could further increase the susceptibility of forest stands. Forest management, aimed at reducing the occurrence of extensive fir–spruce stands, has been advocated as a long-term solution to the budworm problem. The implementation of this measure at a time when man's actions result in the proliferation of fir presents a most serious challenge to forest managers.

scholarly journals Kalendarze z kolekcji Ignacego Wolskiego w zbiorach Muzeum Narodowego w Krakowie

2019 ◽  
Vol 13 ◽  
pp. 223-255
Author(s):  
Agnieszka Lubera
Keyword(s):  
20Th Century ◽  
18Th Century ◽  
Future Generations ◽  
Early 20Th Century ◽  
National Museum ◽  
The Past ◽  
First Time

A small but valuable collection of calendars was donated to the National Museum in Krakow in 1896, 1898 and 1906 by Ignacy Wolski, a Warsaw bibliophile. In the article an overview of these publications is given for the first time. The donation consists of calendars diverse in form and content, published from the end of the 18th century to the early 20th century. Only ten of them were found during the research in the Museum. Most of the preserved calendars was marked with characteristic provenance stamps or stickers;a part of them has some historical notes written by Wolski. They are a great testimony of the past. Wolski’s motifs and idea behind collecting calendars and leaving these publications for future generations in the Museum were also presented in the article.

scholarly journals Puisi Arab Bersajak karya Zaini-Solo; Kajian Pedagogi Islam-Modern dalam Manuskrip Nusantara

2018 ◽  
Vol 24 (2) ◽  
pp. 363-378
Author(s):  
Iin Suryaningsih
Keyword(s):  
20Th Century ◽  
Textual Criticism ◽  
Early 20Th Century ◽  
Western Education ◽  
Modern Education ◽  
The Past ◽  
Arabic Script ◽  
History Of ◽  
Specific Theme

The presence of various modern pedagogical currents carried by the psychologists and observers of Western education, has made a new mapping in the study of modern education in Indonesia. Indeed the study has been popular since the early 20th century AD with a very specific theme evidenced by one of the manuscripts entitled Mir'ātu Afkār al-Rijāl Nadzm Ta'līm al-Muta'līm by a scholar from Solo-Indonesia. This study proves that the content of Modern Pedagogy study by a scholar in Indonesia looks very specific and holistic. The method used is a method of philology that includes textual criticism in manuscripts. This method will also capture the superiority of the study of Archipelago Pedagogy written with Arabic script. The results of this study that the study of Modern Pedagogy can be clearly found in the traces of the history of the past in the archipelago of Manuscript.---Hadirnya berbagai aliran pedagogi modern yang diusung oleh para psikolog dan pemerhati pendidikan Barat, telah membuat pemetaan baru dalam kajian ilmu pendidikan modern di Indonesia. Sejatinya kajian tersebut sudah populer sejak awal abad 20 Masehi dengan tema yang sangat spesifik yang dibuktikan oleh salah satu manuskrip berjudul  Mir’ātu Afkār al-Rijāl Nadzm Ta’līm al-Muta’līm karya seorang cendikia asal Solo-indonesia. Penelitian ini membuktikan bahwa muatan kajian Pedagogi Modern karya cendikia di Indonesia terlihat sangat spesifik dan holistik. Metode yang digunakan adalah metode filologi yang mencakup kritik teks pada manuskrip. Metode ini juga akan memotret keunggulan kajian Pedagogi Nusantara yang ditulis dengan skrip Arab. Hasil penelitian ini bahwa kajian Pedagogi Modern secara nyata dapat kita temukan dalam jejak sejarah keilmuan masa lalu di Nusantara berupa Manuskrip.

Sign in / Sign up

Export Citation Format

Share Document