scholarly journals Interdecadal Variations of Persistent Extreme Heat Events in Eastern China Under Global Warming

2021 ◽  
Author(s):  
Naihui Zang ◽  
Junhu Zhao ◽  
Pengcheng Yan ◽  
Han Zhang ◽  
Shankai Tang ◽  
...  
Keyword(s):  
Global Warming ◽  
21St Century ◽  
South China ◽  
North China ◽  
Eastern China ◽  
Extreme Heat ◽  
Maximum Temperature ◽  
Extreme Heat Events ◽  
June July ◽  
Heat Events

Abstract Persistent extreme heat events (PEHEs) exert a more negative impact on society, including agriculture, plant phenology, power production and human health, compared to general EHEs. The temporal and spatial characteristics of summer PEHEs in eastern China were analysed based on a daily maximum temperature dataset from 759 stations over the period of 1961–2018. The results show the following: Persistent distributions of PEHEs show that they are characterized by an exponential decay with a drop in the decay rate. In terms of spatial distribution, there is an apparent regional difference in the duration of PEHEs. North China is dominated by multi-frequency and short-duration EHEs, while South China is the opposite. PEHEs in North China and the Huanghuai region mainly occur in June-July but mostly in July and August in South China. Strongly responding to global warming, the frequency and duration of PEHEs in North China have increased since the 1990s. However, the frequency of PEHEs in North China and the Huanghuai region has shown opposite trends in June-July since the beginning of the 21st century. Affected by the atmospheric circulations, the regional differences in PEHE frequency are also apparent. Since the beginning of the 21st century, the PEHEs in North China and the Huanghuai area have shown an increasing trend in August. The short-term PEHEs in the middle and lower reaches of the Yangtze River and South China increased rapidly in the 2000s, while long-term PEHEs increased in the 2010s. This study implies that attention should be paid to not only the frequency of EH days but also to the persistence of EHE which is a key characteristic of damaging EH.

scholarly journals Interdecadal variations of persistent extreme heat events in eastern China under global warming

2021 ◽  
Author(s):  
Naihui Zang ◽  
Junhu Zhao ◽  
Pengcheng Yan ◽  
Han Zhang ◽  
Shankai Tang ◽  
...  
Keyword(s):  
Global Warming ◽  
Eastern China ◽  
Extreme Heat ◽  
Extreme Heat Events ◽  
Heat Events

scholarly journals Regional changes in extreme heat events in China under stabilized 1.5 °C and 2.0 °C global warming

2020 ◽  
Vol 11 (3) ◽  
pp. 198-209 ◽  
Author(s):  
Gu-Wei ZHANG ◽  
Gang ZENG ◽  
Vedaste Iyakaremye ◽  
Qing-Long YOU
Keyword(s):  
Global Warming ◽  
Extreme Heat ◽  
Extreme Heat Events ◽  
Heat Events

scholarly journals High-Resolution WRF Simulation of Extreme Heat Events in Eastern China: Large Sensitivity to Land Surface Schemes

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenjian Hua ◽  
Xuan Dong ◽  
Qingyuan Liu ◽  
Liming Zhou ◽  
Haishan Chen ◽  
...  
Keyword(s):  
High Resolution ◽  
Land Surface ◽  
Eastern China ◽  
Extreme Heat ◽  
Surface Processes ◽  
Energy Fluxes ◽  
Land Surface Processes ◽  
Extreme Heat Events ◽  
The Relationship ◽  
Heat Events

Regional climate models with high-resolution simulation are particularly useful for providing a detailed representation of land surface processes, and for studying the relationship between land surface processes and heat events. However, large differences and uncertainties exist among different land surface schemes (LSSs). This study comprehensively assesses the sensitivity to different LSSs based on two extreme heat events in eastern China using the Weather Research and Forecasting (WRF) model. Among the five LSSs (i.e., 5TD, CLM4, Noah, Noah-MP and RUC), Noah is closest to observations in reproducing the temperatures and energy fluxes for both two heat events. The modeled warm biases result mainly from the underestimation of evapotranspirative cooling. Our results show that how each LSS partitions the evapotranspiration (ET) and sensible heat largely determines the relationship between the temperature and turbulent fluxes. Although the simulated two extreme heat events manifest similar biases in the temperatures and energy fluxes, the land surface responses (ET and soil moisture) are different.

A population-based case–control study of the association between weather-related extreme heat events and low birthweight

2020 ◽  
pp. 1-8
Author(s):  
Wayne R. Lawrence ◽  
Aida Soim ◽  
Wangjian Zhang ◽  
Ziqiang Lin ◽  
Yi Lu ◽  
...  
Keyword(s):  
Case Control Study ◽  
First Trimester ◽  
Population Based ◽  
Case Control ◽  
Extreme Heat ◽  
Maximum Temperature ◽  
Extreme Heat Events ◽  
The Impact ◽  
Heat Events ◽  
Control Study

Abstract Although prenatal exposure to high ambient temperatures were reported to be associated with preterm birth, limited research assessed the impact of weather-related extreme heat events (EHE) on birthweight, particularly by trimester. We, therefore, investigated the impact of prenatal EHE on birthweight among term babies (tLBW) by trimester and birthweight percentile. We conducted a population-based case–control study on singleton live births at 38–42 gestational weeks in New York State (NYS) by linking weather data with NYS birth certificates. A total of 22,615 cases were identified as birthweight <2500 gram, and a random sample of 139,168 normal birthweight controls was included. EHE was defined as three consecutive days with the maximum temperatures of ≥32.2 °C/90 °F (EHE90) and two consecutive days of temperatures ≥97th percentile (EHE97) based on the distribution of the maximum temperature for the season and region. We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) with multivariable unconditional logistic regression, controlling for confounders. Overall exposure to EHE97 for 2 d was associated with tLBW (OR 1.05; 95% CI 1.02, 1.09); however, the strongest associations were only observed in the first trimester for both heat indicators, especially when exposure was ≥3 d (ORs ranged: 1.06–1.13). EHE in the first trimester was associated with significant reduction in mean birthweight from 26.78 gram (EHE90) to 36.25 gram (EHE97), which mainly affected the 40th and 60th birthweight percentiles. Findings revealed associations between multiple heat indicators and tLBW, where the impact was consistently strongest in the first trimester.

scholarly journals Forewarned is Forearmed: Extended-Range Forecast Guidance of Recent Extreme Heat Events in Australia

2016 ◽  
Vol 31 (3) ◽  
pp. 697-711 ◽  
Author(s):  
D. Hudson ◽  
A. G. Marshall ◽  
O. Alves ◽  
G. Young ◽  
D. Jones ◽  
...  
Keyword(s):  
Large Scale ◽  
Heat Waves ◽  
Weather Forecast ◽  
Seasonal Prediction ◽  
Extreme Heat ◽  
Maximum Temperature ◽  
Extreme Heat Events ◽  
Extended Range ◽  
Heat Events ◽  
Forecast Guidance

Abstract There has been increasing demand in Australia for extended-range forecasts of extreme heat events. An assessment is made of the subseasonal experimental guidance provided by the Bureau of Meteorology’s seasonal prediction system, Predictive Ocean Atmosphere Model for Australia (POAMA, version 2), for the three most extreme heat events over Australia in 2013, which occurred in January, March, and September. The impacts of these events included devastating bushfires and damage to crops. The outlooks performed well for January and September, with forecasts indicating increased odds of top-decile maximum temperature over most affected areas at least one week in advance for the fortnightly averaged periods at the start of the heat waves and for forecasts of the months of January and September. The March event was more localized, affecting southern Australia. Although the anomalously high sea surface temperature around southern Australia in March (a potential source of predictability) was correctly forecast, the forecast of high temperatures over the mainland was restricted to the coastline. September was associated with strong forcing from some large-scale atmospheric climate drivers known to increase the chance of having more extreme temperatures over parts of Australia. POAMA-2 was able to forecast the sense of these drivers at least one week in advance, but their magnitude was weaker than observed. The reasonably good temperature forecasts for September are likely due to the model being able to forecast the important climate drivers and their teleconnection to Australian climate. This study adds to the growing evidence that there is significant potential to extend and augment traditional weather forecast guidance for extreme events to include longer-lead probabilistic information.

scholarly journals P064: Hot days make for long stays: the impact of extreme heat events on emergency department lengths of stay and volumes in two Canadian community hospitals

CJEM ◽  
2020 ◽  
Vol 22 (S1) ◽  
pp. S87-S87
Author(s):  
F. Kegel ◽  
O. Luo ◽  
S. Richer
Keyword(s):  
Emergency Services ◽  
Heat Waves ◽  
A Priori ◽  
Extreme Heat ◽  
System Capacity ◽  
Maximum Temperature ◽  
Community Hospitals ◽  
Extreme Heat Events ◽  
The Impact ◽  
Heat Events

Introduction: The average temperature in Canada has risen 1.7°C between 1948-2016, increasing the frequency, severity and duration of extreme heat events. These events can exacerbate underlying health conditions, bringing patients to emergency departments (EDs). There is limited data associating sustained heat events to Canadian ED volumes and performance. This retrospective analysis assessed the impact of humidex and temperature on ED volume and length of stay (LOS). Methods: LOS is an indicator of ED overcrowding and system performance. The authors compared median and maximum LOS (hours) and patient volumes in both ambulatory and stretcher ED sections of two community hospitals (NDH, VH) in Montreal, QC to humidex and temperature during the summers of 2016-2018. Data were analyzed with one-way ANOVA and post hoc means analysis with Fisher LSD tests of a priori determined thresholds of mean three-day maximum humidex and temperature preceding ED presentation. Results: The mean maximum humidex and temperature values for the 2016-2018 summers in Montreal, QC were 30.4 and 26.1°C, respectively (n = 276 days). Elevated mean three-day maximum humidex was associated with increased ED volumes (F[3,88] = 4.2,p = 0.008) and median LOS (F[3,88] = 7.7,p = 0.0001) in the NDH. Mean three-day maximum humidex was associated with ED volumes (F[3,272) = 2.9,p = 0.03) but not with median and maximum LOS (p > 0.05) in the VH. Parallel comparisons with mean three-day maximum temperature similarly showed an association with increased ED volumes (F[3,88] = 5.0,p = 0.003) and increased duration of median LOS (F[3,88] = 3.5,p = 0.02) in the NDH. Mean three-day maximum temperature was associated with increased ED volumes (F[3,272] = 3.3,p = 0.02) but not with median and maximum LOS (p > 0.05) in the VH. Conclusion: Warming climates are associated with an increased number of ED presentations and longer median ED LOS. As heat events disproportionately impacted NDH, future investigations need to determine why these two hospitals were affected differently. This study provides local evidence that climate change can disrupt emergency services by increasing the demand for and delaying timely care. This is the first study that the authors are aware of that demonstrates these findings. Hospitals need to be climate ready. Heat waves often happen during times when summer bed closures and vacations already impact system capacity. EDs should dynamically adapt to meet community needs during periods of extreme heat.

scholarly journals Great Lakes Basin Heat Waves: An Analysis of Their Increasing Probability of Occurrence Under Global Warming

2021 ◽  
Vol 3 ◽  
Author(s):  
Fengyi Xie ◽  
Andre R. Erler ◽  
Deepak Chandan ◽  
W. Richard Peltier
Keyword(s):  
Global Warming ◽  
Great Lakes ◽  
Heat Waves ◽  
Extreme Heat ◽  
Occurrence Rate ◽  
Great Lakes Basin ◽  
Extreme Heat Events ◽  
The Future ◽  
Instrumental Period ◽  
Heat Events

Extreme heat events in the Great Lakes Basin (GLB) region of eastern North America are expected to increase in concert with greenhouse gas (GHG) induced global warming. The extent of this regional increase is also influenced by the direct effects of the Great Lakes themselves. This paper describes results from an ensemble of dynamically downscaled global warming projection using the Weather Research and Forecast (WRF) regional climate model coupled to the Freshwater Lake (FLake) model over the Great Lakes region. In our downscaling pipeline, we explore two sets of WRF physics configurations, with the initial and boundary conditions provided by four different fully coupled Global Climate Models (GCMs). Three time periods are investigated, namely an instrumental period (1979–1989) that is employed for validation, and a mid-century (2050–2060) and an end-century (2085–2100) periods that are used to understand the future impacts of global warming. Results from the instrumental period are characterized by large variations in climate states between the ensemble members, which is attributed to differences in both GCM forcing and WRF physics configuration. Results for the future periods, however, are such that the regional model results have good agreement with GCM results insofar as the rise of average temperature with GHG is concerned. Analysis of extreme heat events suggests that the occurrence rate of such events increase steadily with rising temperature, and that the Great Lakes exert strong lake effect influence on extreme heat events in this region.

Large-Scale Circulation Anomalies and Intraseasonal Oscillations Associated with Long-Lived Extreme Heat Events in South China

2017 ◽  
Vol 31 (1) ◽  
pp. 213-232 ◽  
Author(s):  
Ruidan Chen ◽  
Zhiping Wen ◽  
Riyu Lu
Keyword(s):  
South China ◽  
Large Scale ◽  
Eastern China ◽  
Intraseasonal Oscillation ◽  
Extreme Heat ◽  
Western Pacific ◽  
Large Scale Circulation ◽  
Extreme Heat Events ◽  
Circulation Anomalies ◽  
The Western Pacific

Abstract South China experiences extreme heat (EH) most frequently in eastern China. This study specifically explores the large-scale circulation anomalies associated with long-lived EH events in south China. The results show that there is an anomalous cyclone (anticyclone) and active (inactive) convection over south China (the western Pacific) before the EH onset; then, an anticyclone develops and moves northwestward and dominates over south China on the onset day. The anomalous anticyclone maintains its strength over south China and then diminishes and is replaced by another cyclone migrating from the western Pacific after the final day of the EH event. Consequently, the temperature increases over south China around the onset day and is anomalously warm for approximately 10 days on average and then decreases shortly thereafter. The fluctuating anomalies over south China and the western Pacific are intimately related to two intraseasonal oscillation (ISO) modes, namely, the 5–25- and 30–90-day oscillations, which originate from the tropical western Pacific and propagate northwestward. The 5–25-day oscillation is vital to triggering and terminating EH, accounting for approximately half of the original temperature and circulation anomaly transitions. The 30–90-day oscillation favors the persistent warming during EH events, accounting for approximately one-third of the original prolonged warming and anticyclonic anomaly. This result suggests that different ISO modes play crucial roles at different stages of the events. Moreover, a higher annual frequency of long-lived EH days in south China is associated with the transition phase from El Niño to La Niña. It is suggested that both medium-range and interannual forecasting of long-lived EH in south China are possible.

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