scholarly journals Projection of Future Heat Waves in the United States. Part I: Selecting a Climate Model Subset

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 587
Author(s):  
Javad Shafiei Shiva ◽  
David G. Chandler
Keyword(s):  
United States ◽  
General Circulation ◽  
Climate Model ◽  
Heat Waves ◽  
Well Being ◽  
General Circulation Models ◽  
The United States ◽  
Wide Range ◽  
Overall Performance ◽  
Impact Predictions

The widespread increase in global temperature is driving more frequent and more severe local heatwaves within the contiguous United States (CONUS). General circulation models (GCMs) show increasing, but spatially uneven trends in heatwave properties. However, the wide range of model outputs raises the question of the suitability of this method for indicating the future impacts of heatwaves on human health and well-being. This work examines the fitness of 32 models from CMIP5 and their ensemble median to predict a set of heatwave descriptors across the CONUS, by analyzing their capabilities in the simulation of historical heatwaves during 1950–2005. Then, we use a multi-criteria decision-making tool and rank the overall performance of each model for 10 locations with different climates. We found GCMs have different capabilities in the simulation of historical heatwave characteristics. In addition, we observed similar performances for GCMs over the areas with a partially similar climate. The ensemble model showed better performance in simulation of historical heatwave intensity in some locations, while other individual GCMs represented heatwave time-related components more similar to observations. These results are a step towards the use of contemporary weather models to guide heatwave impact predictions.

scholarly journals Regional Climate Model Projections and Uncertainties of U.S. Summer Heat Waves

2010 ◽  
Vol 23 (16) ◽  
pp. 4447-4458 ◽  
Author(s):  
Kenneth E. Kunkel ◽  
Xin-Zhong Liang ◽  
Jinhong Zhu
Keyword(s):  
United States ◽  
Regional Climate Model ◽  
Heat Wave ◽  
General Circulation ◽  
Climate Model ◽  
Heat Waves ◽  
Regional Climate ◽  
General Circulation Models ◽  
Threshold Temperature ◽  
Wave Characteristics

Abstract Regional climate model (RCM) simulations, driven by low and high climate-sensitivity coupled general circulation models (CGCMs) under various future emissions scenarios, were compared to projected changes in heat wave characteristics. The RCM downscaling reduces the CGCM biases in heat wave threshold temperature by a factor of 2, suggesting a higher credibility in the future projections. All of the RCM simulations suggest that there is a high probability of heat waves of unprecedented severity by the end of the twenty-first century if a high emissions path is followed. In particular, the annual 3-day heat wave temperature increases generally by 3°–8°C; the number of heat wave days increases by 30–60 day yr−1 over much of the western and southern United States with slightly smaller increases elsewhere; the variance spectra for intermediate, 3–7 days (prolonged, 7–14 days), temperature extremes increase (decrease) in the central (western) United States. If a lower emissions path is followed, then the outcomes range from quite small changes to substantial increases. In all cases, the mean temperature climatological shift is the dominant change in heat wave characteristics, suggesting that adaptation and acclimatization could reduce effects.

Application of Cluster Analysis to Climate Model Performance Metrics

2011 ◽  
Vol 50 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Satoru Yokoi ◽  
Yukari N. Takayabu ◽  
Kazuaki Nishii ◽  
Hisashi Nakamura ◽  
Hirokazu Endo ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
General Circulation ◽  
Performance Metrics ◽  
Climate Model ◽  
Model Performance ◽  
General Circulation Models ◽  
Clustering Methods ◽  
Dynamic Constraints ◽  
Overall Performance

AbstractThe overall performance of general circulation models is often investigated on the basis of the synthesis of a number of scalar performance metrics of individual models that measure the reproducibility of diverse aspects of the climate. Because of physical and dynamic constraints governing the climate, a model’s performance in simulating a certain aspect of the climate is sometimes related closely to that in simulating another aspect, which results in significant intermodel correlation between performance metrics. Numerous metrics and intermodel correlations may cause a problem in understanding the evaluation and synthesizing the metrics. One possible way to alleviate this problem is to group the correlated metrics beforehand. This study attempts to use simple cluster analysis to group 43 performance metrics. Two clustering methods, the K-means and the Ward methods, yield considerably similar clustering results, and several aspects of the results are found to be physically and dynamically reasonable. Furthermore, the intermodel correlation between the cluster averages is considerably lower than that between the metrics. These results suggest that the cluster analysis is helpful in obtaining the appropriate grouping. Applications of the clustering results are also discussed.

scholarly journals North American April tornado occurrences linked to global sea surface temperature anomalies

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw9950 ◽  
Author(s):  
J.-E. Chu ◽  
A. Timmermann ◽  
J.-Y. Lee
Keyword(s):  
United States ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North American ◽  
General Circulation ◽  
Large Scale ◽  
Moisture Flux ◽  
General Circulation Models ◽  
The United States ◽  
Sea Surface

Annual tornado occurrences over North America display large interannual variability and a statistical linkage to sea surface temperature (SST) anomalies. However, the underlying physical mechanisms for this connection and its modulation in a rapidly varying seasonal environment still remain elusive. Using tornado data over the United States from 1954 to 2016 in combination with SST-forced atmospheric general circulation models, we show a robust dynamical linkage between global SST conditions in April, the emergence of the Pacific-North American teleconnection pattern (PNA), and the year-to-year tornado activity in the Southern Great Plains (SGP) region of the United States. Contrasting previous studies, we find that only in April SST-driven atmospheric circulation anomalies can effectively control the northward moisture-laden flow from the Gulf of Mexico, boosting low-level moisture flux convergence over the SGP. These strong large-scale connections are absent in other months because of the strong seasonality of the PNA and background moisture conditions.

scholarly journals Atlantic Multidecadal Variability as a Modulator of Precipitation Variability in the Southwest United States

2018 ◽  
Vol 31 (14) ◽  
pp. 5525-5542 ◽  
Author(s):  
Dong Eun Lee ◽  
Mingfang Ting ◽  
Nicolas Vigaud ◽  
Yochanan Kushnir ◽  
Anthony G. Barnston
Keyword(s):  
United States ◽  
General Circulation ◽  
Thermal Structure ◽  
Daily Rainfall ◽  
General Circulation Models ◽  
The United States ◽  
Cold Season ◽  
Atlantic Multidecadal Variability ◽  
Multidecadal Variability ◽  
Upper Level

AbstractTwo independent atmospheric general circulation models reveal that the positive (negative) phase of Atlantic multidecadal variability (AMV) can reduce (amplify) the variance of the shorter time-scale (e.g., ENSO related) precipitation fluctuations in the United States, especially in the Southwest, as well as decrease (increase) the long-term seasonal mean precipitation for the cold season. The variance is modulated because of changes in 1) dry day frequency and 2) maximum daily rainfall intensity. With positive AMV forcing, the upper-level warming originating from the increased precipitation over the tropical Atlantic Ocean changes the mean vertical thermal structure over the United States continent to a profile less favorable for rain-inducing upward motions. In addition, a northerly low-level dry advection associated with the local overturning leaves less available column moisture for condensation and precipitation. The opposite conditions occur during cold AMV periods.

scholarly journals Can CGCMs Simulate the Twentieth-Century “Warming Hole” in the Central United States?

2006 ◽  
Vol 19 (17) ◽  
pp. 4137-4153 ◽  
Author(s):  
Kenneth E. Kunkel ◽  
Xin-Zhong Liang ◽  
Jinhong Zhu ◽  
Yiruo Lin
Keyword(s):  
United States ◽  
Twentieth Century ◽  
General Circulation ◽  
Initial Conditions ◽  
Regional Scale ◽  
General Circulation Models ◽  
Internal Dynamic ◽  
External Forcings ◽  
Wide Range ◽  
Central United States

Abstract The observed lack of twentieth-century warming in the central United States (CUS), denoted here as the “warming hole,” was examined in 55 simulations driven by external historical forcings and in 19 preindustrial control (unforced) simulations from 18 coupled general circulation models (CGCMs). Twentieth-century CUS trends were positive for the great majority of simulations, but were negative, as observed, for seven simulations. Only a few simulations exhibited the observed rapid rate of warming (cooling) during 1901–40 (1940–79). Those models with multiple runs (identical forcing but different initial conditions) showed considerable intramodel variability with trends varying by up to 1.8°C century−1, suggesting that internal dynamic variability played a major role at the regional scale. The wide range of trend outcomes, particularly for those models with multiple runs, and the small number of simulations similar to observations in both the forced and unforced experiments suggest that the warming hole is not a robust response of contemporary CGCMs to the estimated external forcings. A more likely explanation based on these models is that the observed warming hole involves external forcings combined with internal dynamic variability that is much larger than typically simulated. The observed CUS temperature variations are positively correlated with North Atlantic (NA) sea surface temperatures (SSTs), and both NA SSTs and CUS temperature are negatively correlated with central equatorial Pacific (CEP) SSTs. Most models simulate rather well the connection between CUS temperature and NA SSTs. However, the teleconnections between NA and CEP SSTS and between CEP SSTs and CUS temperature are poorly simulated and the models produce substantially less NA SST variability than observed, perhaps hampering their ability to reproduce the warming hole.

scholarly journals Diurnal Characteristics of Rainfall over the Contiguous United States and Northern Mexico in the Dynamically Downscaled Reanalysis Dataset (US10)

2012 ◽  
Vol 13 (3) ◽  
pp. 1142-1148 ◽  
Author(s):  
Tomohito J. Yamada ◽  
Myong-In Lee ◽  
Masao Kanamitsu ◽  
Hideki Kanamaru
Keyword(s):  
United States ◽  
General Circulation ◽  
Summer Rainfall ◽  
General Circulation Models ◽  
The United States ◽  
Horizontal Resolution ◽  
Small Scale ◽  
Northern Mexico ◽  
Convective Systems ◽  
Global Reanalysis

Abstract The diurnal characteristics of summer rainfall in the contiguous United States and northern Mexico were examined with the United States reanalysis for 5 years in 10-km horizontal resolution (US10), which is dynamically downscaled from the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) Global Reanalysis 1 using the Regional Spectral Model (RSM). The hourly precipitation outputs demonstrate a realistic structure in the temporal evolution of the observed rainfall episodes and their magnitudes across the United States without any prescriptions of the observed rainfall to the global reanalysis and the downscaled regional reanalysis. Nighttime rainfall over the Great Plains associated with eastward-propagating, mesoscale convective systems originating from the Rocky Mountains is also represented realistically in US10, while the original reanalysis and most general circulation models (GCMs) have difficulties in capturing the series of nocturnal precipitation events in summer over the Plains. The results suggest an important role of the horizontal resolution of the model in resolving small-scale, propagating convective systems to improve the diurnal cycle of summer rainfall.

Dialectical Thinking and Psychological Well-Being in Morocco, China, and the United States

2014 ◽  
Author(s):  
Cassidy Bibo ◽  
Julie Spencer-Rodgers ◽  
Benaissa Zarhbouch ◽  
Mostafa Bouanini ◽  
Kaiping Peng
Keyword(s):  
United States ◽  
Well Being ◽  
The United States ◽  
Dialectical Thinking ◽  
Psychological Well Being

The Politics of Precaution

2012 ◽  
Author(s):  
David Vogel
Keyword(s):  
United States ◽  
Animal Feed ◽  
The United States ◽  
Hazardous Substances ◽  
Risk Regulation ◽  
Scientific Certainty ◽  
European Public ◽  
Wide Range ◽  
Regulatory Controls ◽  
Milk Hormones

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.

The link between coronavirus, anxiety, and religious beliefs in the United States and United Kingdom

2020 ◽  
Author(s):  
Francesco Rigoli
Keyword(s):  
United States ◽  
United Kingdom ◽  
Religious Beliefs ◽  
Well Being ◽  
The United States ◽  
Christian Faith ◽  
Stressful Event ◽  
Cultural Implications ◽  
The Impact

Research has shown that stress impacts on people’s religious beliefs. However, several aspects of this effect remain poorly understood, for example regarding the role of prior religiosity and stress-induced anxiety. This paper explores these aspects in the context of the recent coronavirus emergency. The latter has impacted dramatically on many people’s well-being; hence it can be considered a highly stressful event. Through online questionnaires administered to UK and USA citizens professing either Christian faith or no religion, this paper examines the impact of the coronavirus crisis upon common people’s religious beliefs. We found that, following the coronavirus emergency, strong believers reported higher confidence in their religious beliefs while non-believers reported increased scepticism towards religion. Moreover, for strong believers, higher anxiety elicited by the coronavirus threat was associated with increased strengthening of religious beliefs. Conversely, for non-believers, higher anxiety elicited by the coronavirus thereat was associated with increased scepticism towards religious beliefs. These observations are consistent with the notion that stress-induced anxiety enhances support for the ideology already embraced before a stressful event occurs. This study sheds light on the psychological and cultural implications of the coronavirus crisis, which represents one of the most serious health emergencies in recent times.

Consular Protection and Solidarity across Borders

2018 ◽  
Author(s):  
Alexandra Délano Alonso
Keyword(s):  
United States ◽  
Latin American ◽  
Legal Status ◽  
Well Being ◽  
The United States ◽  
Migrant Populations ◽  
Policy Goals ◽  
Large Populations ◽  
Mexican Government ◽  
Working Together

This chapter demonstrates how Latin American governments with large populations of migrants with precarious legal status in the United States are working together to promote policies focusing on their well-being and integration. It identifies the context in which these processes of policy diffusion and collaboration have taken place as well as their limitations. Notwithstanding the differences in capacities and motivations based on the domestic political and economic contexts, there is a convergence of practices and policies of diaspora engagement among Latin American countries driven by the common challenges faced by their migrant populations in the United States and by the Latino population more generally. These policies, framed as an issue of rights protection and the promotion of migrants’ well-being, are presented as a form of regional solidarity and unity, and are also mobilized by the Mexican government as a political instrument serving its foreign policy goals.

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