Mechanisms Contributing to the Warming Hole and the Consequent U.S. East–West Differential of Heat Extremes

2012 ◽  
Vol 25 (18) ◽  
pp. 6394-6408 ◽  
Author(s):  
Gerald A. Meehl ◽  
Julie M. Arblaster ◽  
Grant Branstator
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Linear Trend ◽  
Coupled Model ◽  
The United States ◽  
Convective Heating ◽  
Central Pacific ◽  
Southeastern Part ◽  
Climate System Model ◽  
East West

Abstract A linear trend calculated for observed annual mean surface air temperatures over the United States for the second-half of the twentieth century shows a slight cooling over the southeastern part of the country, the so-called warming hole, while temperatures over the rest of the country rose significantly. This east–west gradient of average temperature change has contributed to the observed pattern of changes of record temperatures as given by the ratio of daily record high temperatures to record low temperatures with a comparable east–west gradient. Ensemble averages of twentieth-century climate simulations in the Community Climate System Model, version 3 (CCSM3), show a slight west–east warming gradient but no warming hole. A warming hole appears in only several ensemble members in the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset and in one ensemble member of simulated twentieth-century climate in CCSM3. In this model the warming hole is produced mostly from internal decadal time-scale variability originating mainly from the equatorial central Pacific associated with the Interdecadal Pacific Oscillation (IPO). Analyses of a long control run of the coupled model, and specified convective heating anomaly experiments in the atmosphere-only version of the model, trace the forcing of the warming hole to positive convective heating anomalies in the central equatorial Pacific Ocean near the date line. Cold-air advection into the southeastern United States in winter, and low-level moisture convergence in that region in summer, contribute most to the warming hole in those seasons. Projections show a disappearance of the warming hole, but ongoing greater surface temperature increases in the western United States compared to the eastern United States.

scholarly journals Intermodel Variability and Mechanism Attribution of Central and Southeastern U.S. Anomalous Cooling in the Twentieth Century as Simulated by CMIP5 Models

2013 ◽  
Vol 26 (17) ◽  
pp. 6215-6237 ◽  
Author(s):  
Zaitao Pan ◽  
Xiaodong Liu ◽  
Sanjiv Kumar ◽  
Zhiqiu Gao ◽  
James Kinter
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Land Surface ◽  
Regional Scale ◽  
Coupled Model ◽  
The United States ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Central United States ◽  
Intercomparison Project

Abstract Some parts of the United States, especially the southeastern and central portion, cooled by up to 2°C during the twentieth century, while the global mean temperature rose by 0.6°C (0.76°C from 1901 to 2006). Studies have suggested that the Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO) may be responsible for this cooling, termed the “warming hole” (WH), while other works reported that regional-scale processes such as the low-level jet and evapotranspiration contribute to the abnormity. In phase 3 of the Coupled Model Intercomparison Project (CMIP3), only a few of the 53 simulations could reproduce the cooling. This study analyzes newly available simulations in experiments from phase 5 of the Coupled Model Intercomparison Project (CMIP5) from 28 models, totaling 175 ensemble members. It was found that 1) only 19 out of 100 all-forcing historical ensemble members simulated negative temperature trend (cooling) over the southeast United States, with 99 members underpredicting the cooling rate in the region; 2) the missing of cooling in the models is likely due to the poor performance in simulating the spatial pattern of the cooling rather than the temporal variation, as indicated by a larger temporal correlation coefficient than spatial one between the observation and simulations; 3) the simulations with greenhouse gas (GHG) forcing only produced strong warming in the central United States that may have compensated the cooling; and 4) the all-forcing historical experiment compared with the natural-forcing-only experiment showed a well-defined WH in the central United States, suggesting that land surface processes, among others, could have contributed to the cooling in the twentieth century.

scholarly journals Characteristics of Drought and Persistent Wet Spells over the United States in the Atmosphere–Land–Ocean Coupled Model Experiments

2012 ◽  
Vol 16 (9) ◽  
pp. 1-26 ◽  
Author(s):  
Kingtse C. Mo ◽  
Lindsey N. Long ◽  
Jae-Kyung E. Schemm
Keyword(s):  
United States ◽  
Extreme Events ◽  
General Circulation ◽  
Coupled Model ◽  
Circulation Model ◽  
The United States ◽  
Agricultural Drought ◽  
The West ◽  
East West ◽  
Wet Spells

Abstract Atmosphere–land–ocean coupled model simulations are examined to diagnose the ability of models to simulate drought and persistent wet spells over the United States. A total of seven models are selected for this study. They are three versions of the NCEP Climate Forecast System (CFS) coupled general circulation model (CGCM) with a T382, T126, and T62 horizontal resolution; GFDL Climate Model version 2.0 (CM2.0); GFDL CM2.1; Max Planck Institute (MPI) ECHAM5; and third climate configuration of the Met Office Unified Model (HadCM3) simulations from the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) experiments. Over the United States, drought and persistent wet spells are more likely to occur over the western interior region, while extreme events are less likely to persist over the eastern United States and the West Coast. For meteorological drought, which is defined by precipitation (P) deficit, the east–west contrast is well simulated by the CFS T382 and the T126 models. The HadCM3 captures the pattern but not the magnitudes of the frequency of occurrence of persistent extreme events. For agricultural drought, which is defined by soil moisture (SM) deficit, the CFS T382, CFS T126, MPI ECHAM5, and HadCM3 models capture the east–west contrast. The models that capture the west–east contrast also have a realistic P climatology and seasonal cycle. ENSO is the dominant mode that modulates P over the United States. A model needs to have the ENSO mode and capture the mean P responses to ENSO in order to simulate realistic drought. To simulate realistic agricultural drought, the model needs to capture the persistence of SM anomalies over the western region.

Trust, but Verify

2016 ◽  
Keyword(s):  
United States ◽  
Cold War ◽  
Soviet Union ◽  
International Relations ◽  
Arms Control ◽  
The United States ◽  
The Soviet Union ◽  
The Cold War ◽  
East West

This book uses trust—with its emotional and predictive aspects—to explore international relations in the second half of the Cold War, beginning with the late 1960s. The détente of the 1970s led to the development of some limited trust between the United States and the Soviet Union, which lessened international tensions and enabled advances in areas such as arms control. However, it also created uncertainty in other areas, especially on the part of smaller states that depended on their alliance leaders for protection. The chapters in this volume look at how the “emotional” side of the conflict affected the dynamics of various Cold War relations: between the superpowers, within the two ideological blocs, and inside individual countries on the margins of the East–West confrontation.

The Insidious Momentum of American Mass Incarceration

2020 ◽  
Author(s):  
Franklin E. Zimring
Keyword(s):  
United States ◽  
Public Policy ◽  
Twentieth Century ◽  
Mass Incarceration ◽  
The United States ◽  
Next Generation ◽  
Single Generation ◽  
American Life ◽  
Peak Rate ◽  
Or Practice

The phenomenal growth of penal confinement in the United States in the last quarter of the twentieth century is still a public policy mystery. Why did it happen when it happened? What explains the unprecedented magnitude of prison and jail expansion? Why are the current levels of penal confinement so very close to the all-time peak rate reached in 2007? What is the likely course of levels of penal confinement in the next generation of American life? Are there changes in government or policy that can avoid the prospect of mass incarceration as a chronic element of governance in the United States? This study is organized around four major concerns: What happened in the 33 years after 1973? Why did these extraordinary changes happen in that single generation? What is likely to happen to levels of penal confinement in the next three decades? What changes in law or practice might reduce this likely penal future?

Orientalized Aztecs: Observations on the Americanization of Theatrical Dance

2019 ◽  
Vol 51 (2) ◽  
pp. 35-50
Author(s):  
K. Mitchell Snow
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Manifest Destiny ◽  
The United States ◽  
United States Policy ◽  
Ballets Russes

The opening decades of the twentieth century saw a passing fashion for “Aztec” dancing in the vaudeville theaters of the United States. Russian classical dancers Kosloff and Fokine tapped the orientalist currents of the Ballets Russes, adopting the Aztec as superficial signs of the American. Conversely, works by Shawn and film director Cecil B. DeMille, which served as points of reference for the Russians, represented a continuation of equally orientalist attitudes toward Mexico's past, forged during the realization of the United States’ policy of Manifest Destiny. The emergence of a cadre of trained dancers from Mexico, trained by students of Kosloff and Shawn, would bring a distinctively different perspective on the presentation of their heritage to the dance stage, one that was no longer based in the imagination of an expansionist America.

A Century of America on Chinese Screens

2010 ◽  
Vol 17 (4) ◽  
pp. 305-323 ◽  
Author(s):  
Zhiwei Xiao
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Print Media ◽  
The United States ◽  
Sharp Contrast ◽  
American People ◽  
Early Twentieth Century ◽  
History Of ◽  
Chinese Films ◽  
New Millennium

AbstractNo serious study has been published on how Chinese filmmakers have portrayed the United States and the American people over the last century. The number of such films is not large. That fact stands in sharp contrast not only to the number of "China pictures" produced in the United States, which is not surprising, but also in contrast to the major role played by Chinese print media. This essay surveys the history of Chinese cinematic images of America from the early twentieth century to the new millennium and notes the shifts from mostly positive portrayal in the pre-1949 Chinese films, to universal condemnation during the Mao years and to a more nuanced, complex, and multi-colored presentation of the last few decades.

Sign in / Sign up

Export Citation Format

Share Document