Decreasing Reliability and Increasing Synchroneity of Western North American Streamflow

2005 ◽  
Vol 18 (5) ◽  
pp. 613-618 ◽  
Author(s):  
Shaleen Jain ◽  
Martin Hoerling ◽  
Jon Eischeid
Keyword(s):  
Twentieth Century ◽  
Water Resources ◽  
North America ◽  
Atmospheric Circulation ◽  
River Basins ◽  
Western North America ◽  
Hydrologic Change ◽  
Late Twentieth ◽  
Major River ◽  
Late Twentieth Century

Abstract Assessing climate-related societal vulnerability and mitigating impacts requires timely diagnosis of the nature of regional hydrologic change. A late-twentieth-century emergent trend is discovered toward increasing year-to-year variance (decreasing reliability) of streamflow across the major river basins in western North America—–Fraser, Columbia, Sacramento–San Joaquin, and Upper Colorado. Simultaneously, a disproportionate increase in the incidence of synchronous flows (simultaneous high or low flows across all four river basins) has resulted in expansive water resources stress. The observed trends have analogs in wintertime atmospheric circulation regimes and ocean temperatures, raising new questions on the detection, attribution, and projection of regional hydrologic change induced by climate.

scholarly journals Changes of Glaciers and Climate in Northwestern North America during the Late Twentieth Century

2009 ◽  
Vol 22 (15) ◽  
pp. 4117-4134 ◽  
Author(s):  
Anthony Arendt ◽  
John Walsh ◽  
William Harrison
Keyword(s):  
Twentieth Century ◽  
North America ◽  
Recent Period ◽  
Freezing Level ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Late Twentieth ◽  
Climate Station ◽  
Northwestern North America ◽  
Late Twentieth Century

Abstract About 75% of 46 glaciers measured using repeat airborne altimetry in Alaska and northwestern Canada have been losing mass at an increasing rate from the mid-1990s to the middle of the first decade of the twenty-first century, relative to an earlier period beginning in the 1950s–70s. The remaining glaciers have been either gaining mass during the more recent period or continuing to lose mass, but at a decreasing rate. Temperature and precipitation data at 67 climate stations were examined to explain these changes. Nearly all significant changes in winter (October–April) and summer (May–September) air temperatures were positive (2.0° ± 0.8° and 1.0° ± 0.4°C) between 1950 and 2002, and all seasonally averaged values of freezing level heights (FLH) increased during the same time period. A small increase in precipitation was observed, but these changes were significant at only 17% of the stations. Regional glacier changes, modeled using mass balance sensitivities and climate station temperature and precipitation changes, agreed with observations to within the limits of reported errors. Seasonal variations in accumulation resulted in large uncertainties in the recent period mass variations. In nearly all regions, increasing summer temperatures accounted for most of the glacier mass losses. FLH variations show that the maritime glacier systems are more sensitive to variations in the mean position of the winter FLH than interior regions, suggesting that strong winter warming has affected these regions in addition to the summer changes. These measurements augment the increasingly strong evidence of late twentieth-century climate change in northwestern North America.

scholarly journals Tree-Ring-Reconstructed Summer Temperatures from Northwestern North America during the Last Nine Centuries*

2013 ◽  
Vol 26 (10) ◽  
pp. 3001-3012 ◽  
Author(s):  
Kevin J. Anchukaitis ◽  
Rosanne D. D’Arrigo ◽  
Laia Andreu-Hayles ◽  
David Frank ◽  
Anne Verstege ◽  
...  
Keyword(s):  
Twentieth Century ◽  
North America ◽  
Tree Ring ◽  
Radiative Forcing ◽  
Latewood Density ◽  
Late Twentieth ◽  
Summer Temperatures ◽  
Northwestern North America ◽  
Late Twentieth Century

Abstract Northwestern North America has one of the highest rates of recent temperature increase in the world, but the putative “divergence problem” in dendroclimatology potentially limits the ability of tree-ring proxy data at high latitudes to provide long-term context for current anthropogenic change. Here, summer temperatures are reconstructed from a Picea glauca maximum latewood density (MXD) chronology that shows a stable relationship to regional temperatures and spans most of the last millennium at the Firth River in northeastern Alaska. The warmest epoch in the last nine centuries is estimated to have occurred during the late twentieth century, with average temperatures over the last 30 yr of the reconstruction developed for this study [1973–2002 in the Common Era (CE)] approximately 1.3° ± 0.4°C warmer than the long-term preindustrial mean (1100–1850 CE), a change associated with rapid increases in greenhouse gases. Prior to the late twentieth century, multidecadal temperature fluctuations covary broadly with changes in natural radiative forcing. The findings presented here emphasize that tree-ring proxies can provide reliable indicators of temperature variability even in a rapidly warming climate.

How Poetry Matters

2020 ◽  
pp. 1-27
Author(s):  
Rebecca Kosick
Keyword(s):  
Twentieth Century ◽  
North America ◽  
Literary Studies ◽  
Visual Poetry ◽  
Concrete Poetry ◽  
Late Twentieth ◽  
Object Of Study ◽  
Late Twentieth Century ◽  
Linguistic Material

This chapter opens a discussion of how language’s vitality registers in and as material. It assesses the reception of material poetics in late twentieth century North America and compares the examples featured in this book with other investments in poetic materiality. The chapter offers a discussion of the term ‘concrete poetry’ which has lost some of the contextual specificity that historically adhered to it. This history is proved as a way of situating Brazilian concretism and as a way of distinguishing the term’s use from other names for sympathetic forms such as ‘visual poetry’. This chapter makes the case for the term ‘material poetics’ and demonstrates how many of the hybrid linguistic-material practices in the Americas built on early theorisations of language’s matter, which were undertaken with notable depth by the so-called ‘noigandres’ group of Brazilian concrete poets. Literary studies’ adoption of theories of objects and matter are explored along with debates within literary studies that investigate how we read. The introduction takes this book’s featured artists and poets to be its primary theorists and works to test and reframe contemporary thinking on objects by positing the matter of language as its object of study.

Nine Centuries of Man

2017 ◽  
Keyword(s):  
Twentieth Century ◽  
Diverse Range ◽  
Gender Expectations ◽  
Court Records ◽  
The Past ◽  
Wide Range ◽  
Police Reports ◽  
Late Twentieth ◽  
Scottish History ◽  
Late Twentieth Century

What did it mean to be a man in Scotland over the past nine centuries? Scotland, with its stereotypes of the kilted warrior and the industrial ‘hard man’, has long been characterised in masculine terms, but there has been little historical exploration of masculinity in a wider context. This interdisciplinary collection examines a diverse range of the multiple and changing forms of masculinities from the late eleventh to the late twentieth century, exploring the ways in which Scottish society through the ages defined expectations for men and their behaviour. How men reacted to those expectations is examined through sources such as documentary materials, medieval seals, romances, poetry, begging letters, police reports and court records, charity records, oral histories and personal correspondence. Focusing upon the wide range of activities and roles undertaken by men – work, fatherhood and play, violence and war, sex and commerce – the book also illustrates the range of masculinities that affected or were internalised by men. Together, the chapters illustrate some of the ways Scotland’s gender expectations have changed over the centuries and how, more generally, masculinities have informed the path of Scottish history

Trey Ellis's Platitudes: Redefining Black Voices

2009 ◽  
Vol 32 (1) ◽  
pp. 55-76
Author(s):  
Quan Manh Ha
Keyword(s):  
Twentieth Century ◽  
African American ◽  
American Literature ◽  
African American Literature ◽  
Black Experience ◽  
Racial Issues ◽  
Black Voices ◽  
Late Twentieth ◽  
One Year ◽  
Late Twentieth Century

Trey Ellis has emerged as a prominent African American writer of the late-twentieth century, despite the small number of his published works. “The New Black Aesthetic,” an essay that he first published in CaUaloo in 1989, one year after the publication of his first novel, Platitudes, stands as a manifesto that defines and articulates his perspective on the emerging black literary voices and culture of the time, and on “the future of African American artistic expression” in the postmodern era.1 According to Eric Lott, Ellis's novel parodies the literary and cultural conflict between such male experimental writers as lshmael Reed and such female realist writers as Alice Walker.2 Thus, Ellis's primary purpose in writing Platitudes is to redefine how African Americans should be represented in fiction, implying that neither of the dominant approaches can completely articulate late-twentieth-century black experience when practiced in isolation. In its final passages, Platitudes represents a synthesis of the two literary modes or styles, and it embodies quite fully the diversity of black cultural identities at the end of the twentieth century as it extends African American literature beyond racial issues. In this way, the novel exemplifies the literary agenda that Ellis suggests in his theoretical essay.

A New Denominational Historiography?

1995 ◽  
Vol 5 (2) ◽  
pp. 249-263
Author(s):  
John F. Wilson
Keyword(s):  
Twentieth Century ◽  
Recent Analysis ◽  
General Factor ◽  
Religious Organization ◽  
Religious Institution ◽  
Large Numbers ◽  
The Status ◽  
Late Twentieth ◽  
American Society ◽  
Late Twentieth Century

Over the last decade, a noteworthy number of published studies have, in one fashion or another, been defined with reference to religious denominations. This is an arresting fact, for, coincidentally, the status of religious denominations in the society has been called into question. Some formerly powerful bodies have lost membership (at least relatively speaking) and now experience reduced influence, while newer forms of religious organization(s)—e.g., parachurch groups and loosely structured movements—have flourished. The most compelling recent analysis of religion in modern American society gives relatively little attention to them. Why, then, have publications in large numbers appeared, in scale almost seeming to be correlated inversely to this trend?No single answer to this question is adequate. Surely one general factor is that historians often “work out of phase” with contemporary social change. If denominations have been displaced as a form of religious institution in society in the late twentieth century, then their prominence in earlier eras is all the more intriguing.

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