A Comparative Study of Precipitation and Evaporation between CMIP3 and CMIP5 Climate Model Ensembles in Semiarid Regions

2014 ◽  
Vol 27 (10) ◽  
pp. 3731-3749 ◽  
Author(s):  
Noel C. Baker ◽  
Huei-Ping Huang
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Negative Trend ◽  
First Century ◽  
Positive Trend ◽  
Southwestern United States ◽  
Semiarid Regions ◽  
Drying Trend ◽  
Twenty First Century ◽  
Model Ensembles

Abstract The twentieth-century climatology and twenty-first-century trend in precipitation P, evaporation E, and P − E for selected semiarid U.S. Southwest and Mediterranean regions are compared between ensembles from phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5). The twentieth-century simulations are validated with precipitation from observation and evaporation from reanalysis. It is found that the Special Report on Emissions Scenarios (SRES) A1B simulations in CMIP3 and the simulations with representative concentration pathways (RCPs) 4.5 and 8.5 in CMIP5 produce qualitatively similar seasonal cycles of the twenty-first-century trend in P − E for both semiarid regions. For the southwestern United States, it is characterized by a strong drying trend in spring, a weak moistening trend in summer, a weak drying trend in winter, and an overall drying trend for the annual mean. For the Mediterranean region, a drying trend is simulated for all seasons with an October maximum and July minimum. The consistency between CMIP3 and CMIP5 scenarios indicates that the simulated trend is robust; however, while the trend in P − E is negative in spring for the southwestern United States for all CMIP ensembles, CMIP3 predicts a strongly negative trend in P and minor negative trend in E whereas both CMIP5 scenarios predict a nearly zero trend in P and positive trend in E. For the twentieth-century simulations, the P, E, and P − E of the two model ensembles are statistically indistinguishable for most seasons. This “stagnation” of the simulated climatology from CMIP3 to CMIP5 implies that the hydroclimatic variable biases have not decreased in the newer generation of models. Notably, over the southwestern United States the CMIP3 models produce too much precipitation in the cold season. This bias remains almost unchanged in CMIP5.

Rewriting the Captivity Narrative for Contemporary Children: Speare, Bruchac, and the French and Indian War

2011 ◽  
Vol 84 (2) ◽  
pp. 318-346 ◽  
Author(s):  
Sara L. Schwebel
Keyword(s):  
United States ◽  
Twentieth Century ◽  
First Century ◽  
Captivity Narratives ◽  
French And Indian War ◽  
Captivity Narrative ◽  
Twenty First Century ◽  
Anglo American ◽  
Indian War ◽  
War Stories

Juxtaposing the French and Indian War stories of Elizabeth George Speare, a mid-twentieth- century Anglo-American children's author, against those of Joseph Bruchac, a twenty-first- century Abenaki children's author, reveals how flexible and powerful captivity narratives have been in shaping arguments about gender, nationhood, citizenship, and land in the postwar United States.

Interhemispheric Temperature Asymmetry over the Twentieth Century and in Future Projections

2013 ◽  
Vol 26 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Andrew R. Friedman ◽  
Yen-Ting Hwang ◽  
John C. H. Chiang ◽  
Dargan M. W. Frierson
Keyword(s):  
Twentieth Century ◽  
Global Climate ◽  
First Century ◽  
The Arctic ◽  
Positive Trend ◽  
Anthropogenic Aerosols ◽  
Abrupt Decrease ◽  
Tropical Rainfall ◽  
Twenty First Century ◽  
Temperature Asymmetry

Abstract The temperature contrast between the Northern and Southern Hemispheres—the interhemispheric temperature asymmetry (ITA)—is an emerging indicator of global climate change, potentially relevant to the Hadley circulation and tropical rainfall. The authors examine the ITA in historical observations and in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5) simulations. The observed annual-mean ITA (north minus south) has varied within a 0.8°C range and features a significant positive trend since 1980. The CMIP multimodel ensembles simulate this trend, with a stronger and more realistic signal in CMIP5. Both ensembles project a continued increase in the ITA over the twenty-first century, well outside the twentieth-century range. The authors mainly attribute this increase to the uneven spatial impacts of greenhouse forcing, which result in amplified warming in the Arctic and northern landmasses. The CMIP5 specific-forcing simulations indicate that, before 1980, the greenhouse-forced ITA trend was primarily countered by anthropogenic aerosols. The authors also identify an abrupt decrease in the observed ITA in the late 1960s, which is generally not present in the CMIP simulations; it suggests that the observed drop was caused by internal variability. The difference in the strengths of the northern and southern Hadley cells covaries with the ITA in the CMIP5 simulations, in accordance with previous findings; the authors also find an association with the hemispheric asymmetry in tropical rainfall. These relationships imply a northward shift in tropical rainfall with increasing ITA in the twenty-first century, though this result is difficult to separate from the response to global-mean temperature change.

America's Pragmatic Role?

2020 ◽  
Author(s):  
Deborah Avant
Keyword(s):  
United States ◽  
Twentieth Century ◽  
International Relations ◽  
The United States ◽  
Global Leadership ◽  
First Century ◽  
Global Leader ◽  
The Future ◽  
Twenty First Century

Abstract What has made the United States a global leader? Though analysts often attribute American success to a combination of resources and ideas, a subtle undercurrent in these arguments points to pragmatism and the creativity it often generates as an important part of the story. First theorized by American philosophers in the nineteenth and early twentieth centuries, pragmatism emphasizes that creativity can reshape how we see norms and interests to make cooperation more likely. After discussing the basic elements of pragmatism and its intersection with prominent international relations arguments, I show how the creativity that pragmatism envisions appears in each of these books. Though the collected authors do not label themselves as pragmatists, piecing these pragmatic elements together demonstrates the importance of creativity for key global leadership moments in the twentieth century, as well as important, if under-appreciated, governance innovations in the twenty-first century. It also offers insights into how the United States might move into the future.

scholarly journals Physical Mechanisms Related to Climate-Induced Drying of Two Semiarid Watersheds in the Southwestern United States

2014 ◽  
Vol 15 (4) ◽  
pp. 1404-1418 ◽  
Author(s):  
Seshadri Rajagopal ◽  
Francina Dominguez ◽  
Hoshin V. Gupta ◽  
Peter A. Troch ◽  
Christopher L. Castro
Keyword(s):  
United States ◽  
The United States ◽  
Hydrologic Model ◽  
First Century ◽  
Climate Projections ◽  
Southwestern United States ◽  
Study Region ◽  
Model Average ◽  
Basin Scale ◽  
Twenty First Century

Abstract Water managers across the United States face the need to make informed policy decisions regarding long-term impacts of climate change on water resources. To provide a scientifically informed basis for this, the evolution of important components of the basin-scale water balance through the end of the twenty-first century is estimated. Bias-corrected and spatially downscaled climate projections, from phase 3 of the Coupled Model Intercomparison Project (CMIP3) of the World Climate Research Programme, were used to drive a spatially distributed Variable Infiltration Capacity (VIC) model of hydrologic processes in the Salt–Verde basin in the southwestern United States. From the suite of CMIP3 models, the authors select a five-model subset, including three that best reproduce the historical climatology for the study region, plus two others to represent wetter and drier than model average conditions, so as to represent the range of GCM prediction uncertainty. For each GCM, data for three emission scenarios (A1B, A2, and B1) were used to drive the hydrologic model into the future. The projections of this model ensemble indicate a statistically significant 25% decrease in streamflow by the end of the twenty-first century. The primary cause for this change is due to projected decreases in winter precipitation accompanied by significant (temperature driven) reductions in storage of snow and increased winter evaporation. The results show that water management in central Arizona is highly likely to be impacted by changes in regional climate.

scholarly journals Comparing Twentieth- and Twenty-First-Century Patterns of Interannual Precipitation Variability over the Western United States and Northern Mexico*

2012 ◽  
Vol 13 (1) ◽  
pp. 366-378 ◽  
Author(s):  
Tyler W. Ruff ◽  
Yochanan Kushnir ◽  
Richard Seager
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Interannual Variability ◽  
Climate Models ◽  
Precipitation Variability ◽  
First Century ◽  
Western United States ◽  
Spatial Structures ◽  
Northern Mexico ◽  
Twenty First Century

Abstract The ability of coupled climate models to simulate the patterns of interannual precipitation variability over the western half of the United States and northern Mexico is investigated by applying principal component analysis to observations and model output. Global Precipitation Climatology Centre (GPCC) observations are compared to the pooled twentieth-century warm- and cold-season precipitation averages simulated by five coupled global climate models included in the Intergovernmental Panel on Climate Change Fourth Assessment Report. The pooled model spatial structures (EOFs) closely match those of the GPCC observations for both halves of the year. Additionally, the twenty-first-century model pooled EOFs are almost identical in spatial extent and amplitude to their twentieth-century counterparts. Thus, the spatial characteristics of large-scale precipitation variability in the western United States are not projected to change in the twenty-first century. When global observed and modeled seasonally averaged sea surface temperature anomalies are correlated with the time series corresponding to the three leading EOFs to discern sources of each mode of precipitation variability, a pattern reminiscent of El Niño is found to be the only significant association. The spatial structures of variability also appear independent of the model-predicted precipitation trend over the twenty-first century, indicating that the mechanisms responsible for the trend are different from those associated with interannual variability. The results of this study lend confidence in the pooled model predictions of seasonal precipitation patterns, and they suggest that future changes will primarily result from the contribution of the mean trend over which statistically stationary interannual variability is superimposed.

scholarly journals Centennial Trend and Decadal-to-Interdecadal Variability of Atmospheric Angular Momentum in CMIP3 and CMIP5 Simulations

2013 ◽  
Vol 26 (11) ◽  
pp. 3846-3864 ◽  
Author(s):  
Houk Paek ◽  
Huei-Ping Huang
Keyword(s):  
Twentieth Century ◽  
Angular Momentum ◽  
Climate Model ◽  
Atmospheric Angular Momentum ◽  
First Century ◽  
Interdecadal Variability ◽  
Cmip5 Models ◽  
Positive Trend ◽  
Wide Range ◽  
Twenty First Century

Abstract The climatology and trend of atmospheric angular momentum from the phase 3 and the phase 5 Climate Model Intercomparison Project (CMIP3 and CMIP5, respectively) simulations are diagnosed and validated with the Twentieth Century Reanalysis (20CR). It is found that CMIP5 models produced a significantly smaller bias in the twentieth-century climatology of the relative MR and omega MΩ angular momentum compared to CMIP3. The CMIP5 models also produced a narrower ensemble spread of the climatology and trend of MR and MΩ. Both CMIP3 and CMIP5 simulations consistently produced a positive trend in MR and MΩ for the twentieth and twenty-first centuries. The trend for the twenty-first century is much greater, reflecting the role of greenhouse gas (GHG) forcing in inducing the trend. The simulated increase in MR for the twentieth century is consistent with reanalysis. Both CMIP3 and CMIP5 models produced a wide range of magnitudes of decadal and interdecadal variability of MR compared to 20CR. The ratio of the simulated standard deviation of decadal or interdecadal variability to its observed counterpart ranges from 0.5 to over 2.0 for individual models. Nevertheless, the bias is largely random and ensemble averaging brings the ratio to within 18% of the reanalysis for decadal and interdecadal variability for both CMIP3 and CMIP5. The twenty-first-century simulations from both CMIP3 and CMIP5 produced only a small trend in the amplitude of decadal or interdecadal variability, which is not statistically significant. Thus, while GHG forcing induces a significant increase in the climatological mean of angular momentum, it does not significantly affect its decadal-to-interdecadal variability in the twenty-first century.

Great Plains Precipitation and Its SST Links in Twentieth-Century Climate Simulations, and Twenty-First- and Twenty-Second-Century Climate Projections

2010 ◽  
Vol 23 (23) ◽  
pp. 6409-6429 ◽  
Author(s):  
Alfredo Ruiz-Barradas ◽  
Sumant Nigam
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Great Plains ◽  
Summer Precipitation ◽  
Precipitation Variability ◽  
Second Century ◽  
First Century ◽  
Climate Simulations ◽  
Central United States ◽  
Twenty First Century

Abstract The present work assesses spring and summer precipitation over North America as well as summer precipitation variability over the central United States and its SST links in simulations of the twentieth-century climate and projections of the twenty-first- and twenty-second-century climates for the A1B scenario. The observed spatial structure of spring and summer precipitation poses a challenge for models, particularly over the western and central United States. Tendencies in spring precipitation in the twenty-first century agree with the observed ones at the end of the twentieth century over a wetter north-central and a drier southwestern United States, and a drier southeastern Mexico. Projected wetter springs over the Great Plains in the twenty-first and twenty-second centuries are associated with an increase in the number of extreme springs. In contrast, projected summer tendencies have demonstrated little consistency. The associated observed changes in SSTs bear the global warming footprint, which is not well captured in the twentieth-century climate simulations. Precipitation variability over the Great Plains presents a coherent picture in spring but not in summer. Models project an increase in springtime precipitation variability owing to an increased number of extreme springs. The number of extreme droughty (pluvial) events during the spring–fall part of the year is under(over)estimated in the twentieth century without consistent projections. Summer precipitation variability over the Great Plains is linked to SSTs over the Pacific and Atlantic Oceans, with no apparent ENSO link in spite of the exaggerated variability in the equatorial Pacific in climate simulations; this has been identified already in observations and atmospheric models forced with historical SSTs. This link is concealed due to the increased warming in the twenty-first century. Deficiencies in land surface–atmosphere interactions and global teleconnections in the climate models prevent them from a better portrayal of summer precipitation variability in the central United States.

From Vidocq to the Locked Room

2020 ◽  
pp. 163-178
Author(s):  
Stephen Knight
Keyword(s):  
United States ◽  
Twentieth Century ◽  
International Development ◽  
The United States ◽  
Crime Fiction ◽  
First Century ◽  
Transnational Mobility ◽  
Legal Narratives ◽  
History Of ◽  
Twenty First Century

This chapter provides an in-depth history of the international development of the crime genre prior to the twentieth century. The chapter traces the emergence of a transnational genre from the 1700s through legal narratives and Romantic preoccupations and aesthetics in France, Germany, England, the United States, the Scandinavian countries and Australia. While crime fiction scholars have traditionally maintained that the genre emerged in Britain and America, this chapter places doubt on the supposed centrality of the genre’s British and American genealogy. By examining the genre’s early transnational mobility, the chapter challenges the dominant perception that the genre’s transnationality is a consequence of twentieth- and twenty-first-century globalization and, as such, that it is largely a contemporary phenomenon.

Afterword

2018 ◽  
pp. 169-172
Author(s):  
Michael E. Staub
Keyword(s):  
United States ◽  
Twentieth Century ◽  
The United States ◽  
Intelligence Test ◽  
First Century ◽  
Mental Processes ◽  
Stephen Jay Gould ◽  
Twenty First Century ◽  
Mental Testing

In 1905 French physiological psychologist Alfred Binet pioneered a “metrical scale of intelligence,” a practical and easily administered system for establishing a child’s capacity to perform complex mental processes. Binet did not intend his intelligence test—or the score that the test yielded—to be anything more than a method to identify, and thus to assist, children who experienced difficulties with learning. When the concept of IQ arrived on American shores, it rapidly became racialized. That the racialization of mental testing came so powerfully to thrive in the United States was due in no small part, as Stephen Jay Gould has shown, to the growing prestige and influence of the discipline of psychology in the early decades of the twentieth century, the consequences of which live on – however inadvertently – into the twenty-first century

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