Projected changes in heat waves over China: Ensemble result from RegCM4 downscaling simulations

2021 ◽  
Author(s):  
Wenxin Xie ◽  
Botao Zhou ◽  
Zhenyu Han ◽  
Ying Xu
Keyword(s):  
Heat Waves ◽  
Projected Changes

scholarly journals Modeling Northern Hemisphere Summer Heat Extreme Changes and Their Uncertainties Using a Physics Ensemble of Climate Sensitivity Experiments

2006 ◽  
Vol 19 (17) ◽  
pp. 4418-4435 ◽  
Author(s):  
Robin T. Clark ◽  
Simon J. Brown ◽  
James M. Murphy
Keyword(s):  
Structural Changes ◽  
Heat Waves ◽  
Full Range ◽  
Daily Maximum ◽  
Model Parameters ◽  
Mean Values ◽  
Summer Heat ◽  
Modeling Uncertainties ◽  
Physics Ensemble ◽  
Projected Changes

Abstract Changes in extreme daily temperature events are examined using a perturbed physics ensemble of global model simulations under present-day and doubled CO2 climates where ensemble members differ in their representation of various physical processes. Modeling uncertainties are quantified by varying poorly constrained model parameters that control atmospheric processes and feedbacks and analyzing the ensemble spread of simulated changes. In general, uncertainty is up to 50% of projected changes in extreme heat events of the type that occur only once per year. Large changes are seen in distributions of daily maximum temperatures for June, July, and August with significant shifts to warmer conditions. Changes in extremely hot days are shown to be significantly larger than changes in mean values in some regions. The intensity, duration, and frequency of summer heat waves are expected to be substantially greater over all continents. The largest changes are found over Europe, North and South America, and East Asia. Reductions in soil moisture, number of wet days, and nocturnal cooling are identified as significant factors responsible for the changes. Although uncertainty associated with the magnitude of expected changes is large in places, it does not bring into question the sign or nature of the projected changes. Even with the most conservative simulations, hot extreme events are still expected to substantially increase in intensity, duration, and frequency. This ensemble, however, does not represent the full range of uncertainty associated with future projections; for example, the effects of multiple parameter perturbations are neglected, as are the effects of structural changes to the basic nature of the parameterization schemes in the model.

Climate Extremes and Compound Hazards in a Warming World

2020 ◽  
Vol 48 (1) ◽  
pp. 519-548 ◽  
Author(s):  
Amir AghaKouchak ◽  
Felicia Chiang ◽  
Laurie S. Huning ◽  
Charlotte A. Love ◽  
Iman Mallakpour ◽  
...  
Keyword(s):  
Extreme Events ◽  
Climate Models ◽  
Heat Waves ◽  
Climate Extremes ◽  
Well Being ◽  
Theoretical Research ◽  
Aging Infrastructure ◽  
Climate Hazards ◽  
Projected Changes ◽  
Warming World

Climate extremes threaten human health, economic stability, and the well-being of natural and built environments (e.g., 2003 European heat wave). As the world continues to warm, climate hazards are expected to increase in frequency and intensity. The impacts of extreme events will also be more severe due to the increased exposure (growing population and development) and vulnerability (aging infrastructure) of human settlements. Climate models attribute part of the projected increases in the intensity and frequency of natural disasters to anthropogenic emissions and changes in land use and land cover. Here, we review the impacts, historical and projected changes,and theoretical research gaps of key extreme events (heat waves, droughts, wildfires, precipitation, and flooding). We also highlight the need to improve our understanding of the dependence between individual and interrelated climate extremes because anthropogenic-induced warming increases the risk of not only individual climate extremes but also compound (co-occurring) and cascading hazards. ▪  Climate hazards are expected to increase in frequency and intensity in a warming world. ▪  Anthropogenic-induced warming increases the risk of compound and cascading hazards. ▪  We need to improve our understanding of causes and drivers of compound and cascading hazards.

On exposure of land area and population to heat waves and cold waves in a changing climate

2021 ◽  
Author(s):  
Alexander Hampshire ◽  
Neven Fuckar ◽  
Clare Heaviside ◽  
Myles Allen
Keyword(s):  
Heat Waves ◽  
Surface Air Temperature ◽  
Climate Index ◽  
Daily Maximum ◽  
Land Area ◽  
Cold Waves ◽  
Changing Climate ◽  
Thermal Climate ◽  
Heat Extremes ◽  
Projected Changes

<p>As climate changes – potentially to a warmer state than any time during the evolution of humans – heat extremes threatening human health, global ecosystem and socio-economic fabric of our society are occurring at increasing frequency and intensity in most parts of the world. This study examines changes in global land area and population exposed to both tails of temperature distribution in changing climate since heat and cold exposure is directly associated with a range of health impacts and affects thermal comfort and occupational capacity. We first utilise the latest ECMWF atmospheric reanalysis, ERA5, to examine changes over the satellite era (since 1979), and then we explore the equivalent changes in CMIP6 archive of historical runs and future projections. Besides daily maximum and minimum of dry-bulb surface air temperature (SAT), we also consider daily extremes of the universal thermal climate index (UTCI) that includes the influence of humidity, wind and radiation encapsulating the synergetic heat exchanges between the environment and the human body. Our analysis dissects changes in spatial and temporal exposure to both heat waves and cold waves and presents metrics contrasting changes in the opposite extremes of SAT and UTCI distributions. We assess the significance of the observed, modelled and projected changes and relate them to external drivers of climate change.</p>

scholarly journals Response of the HadGEM2 Earth System Model to Future Greenhouse Gas Emissions Pathways to the Year 2300*

2013 ◽  
Vol 26 (10) ◽  
pp. 3275-3284 ◽  
Author(s):  
John Caesar ◽  
Erika Palin ◽  
Spencer Liddicoat ◽  
Jason Lowe ◽  
Eleanor Burke ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Heat Waves ◽  
First Century ◽  
Earth System ◽  
Global Environmental ◽  
Northern High Latitude ◽  
Emissions Scenarios ◽  
Hadley Centre ◽  
Projected Changes ◽  
Atmospheric Co2 Concentrations

Abstract A new ensemble of simulations from the Earth System configuration of the Hadley Centre Global Environmental Model, version 2 (HadGEM2-ES), is used to evaluate the response to historical and projected future greenhouse gas forcings that follow Representative Concentration Pathways (RCPs). In addition to the projected changes during the twenty-first century, extended simulations to the year 2300 allow an investigation into inertia in the climate system post-2100 that may occur even if atmospheric CO2 concentrations have stabilized. Projections of temperature, precipitation, sea level, permafrost, heat waves, and compatible carbon emissions are analyzed. The low emissions scenario RCP2.6 is the only scenario considered here that is approximately consistent with a 2°C global warming limit, though there are regions where local changes in temperature are projected to considerably exceed 2°C, particularly over northern high-latitude areas. An aggressive mitigation approach, represented here by RCP2.6, could contribute to avoiding the larger-magnitude future climate changes projected under higher emissions scenarios. Despite these benefits, changes should still be expected under an aggressive mitigation pathway and may require adaptation.

scholarly journals Analysis of projected changes in the occurrence of heat waves in Hungary

2013 ◽  
Vol 35 ◽  
pp. 115-122 ◽  
Author(s):  
R. Pongrácz ◽  
J. Bartholy ◽  
E. B. Bartha
Keyword(s):  
Regional Climate Model ◽  
Heat Wave ◽  
Climate Model ◽  
Heat Waves ◽  
Meteorological Data ◽  
Regional Climate ◽  
Warning System ◽  
Emissions Scenarios ◽  
Projected Changes ◽  
Regional Climates

Abstract. Heat wave events are important temperature-related hazards due to their impacts on human health. In 2004, a Heat Health Warning System including three levels of heat wave warning was developed on the basis of a retrospective analysis of mortality and meteorological data in Hungary to anticipate heat waves that may result in a large excess of mortality. Projected changes in the frequency of different heat wave warning levels are analysed for the 21st century. For this purpose, outputs of regional climate model PRECIS (Providing REgional Climates for Impacts Studies) are used taking into account three different global emissions scenarios (A2, A1B, B2). The results clearly show an increase in occurrence and length of heat waves with respect to the underlying emissions scenarios and regional climate model used. Moreover, the potential season of heat wave occurrences is projected to be lengthened by two months in 2071–2100 compared to 1961–1990.

scholarly journals Projected Changes in Western U.S. Large-Scale Summer Synoptic Circulations and Variability in CMIP5 Models

2016 ◽  
Vol 29 (16) ◽  
pp. 5965-5978 ◽  
Author(s):  
Matthew C. Brewer ◽  
Clifford F. Mass
Keyword(s):  
United States ◽  
Global Warming ◽  
Geopotential Height ◽  
Large Scale ◽  
Heat Waves ◽  
Vertical Motion ◽  
Western United States ◽  
Cmip5 Models ◽  
Weather And Climate ◽  
Projected Changes

Abstract Large-scale synoptic circulations have a profound effect on western U.S. summer weather and climate. Heat waves, water availability, the distribution of monsoonal moisture, fire-weather conditions, and other phenomena are impacted by the position and amplitude of large-scale synoptic circulations. Furthermore, regional weather is modulated by the interactions of the large-scale flow with terrain and land–water contrasts. It is therefore crucial to understand projected changes in large-scale circulations and their variability under anthropogenic global warming. Although recent research has examined changes in the jet stream, storm tracks, and synoptic disturbances over the Northern Hemisphere under global warming, most papers have focused on the cold season. In contrast, this work analyzes the projected trends in the spatial distribution and amplitude of large-scale synoptic disturbances over the western United States and eastern Pacific during July and August. It is shown that CMIP5 models project weaker mean midtropospheric gradients in geopotential height as well as attenuated temporal variability in geopotential height, temperature, vorticity, vertical motion, and sea level pressure over this region. Most models suggest reduced frequency of troughs and increased frequency of ridges over the western United States. These changes in the variability of synoptic disturbances have substantial implications for future regional weather and climate.

scholarly journals Future Heat Waves in Different European Capitals Based on Climate Change Indicators

2019 ◽  
Vol 16 (20) ◽  
pp. 3959 ◽  
Author(s):  
Jürgen Junk ◽  
Klaus Goergen ◽  
Andreas Krein
Keyword(s):  
Climate Change ◽  
Heat Waves ◽  
Climate Indices ◽  
Climate Change Scenarios ◽  
Reference Period ◽  
Capital Cities ◽  
Air Temperatures ◽  
Exposed Population ◽  
Negative Impacts ◽  
Projected Changes

Changes in the frequency and intensity of heat waves have shown substantial negative impacts on public health. At the same time, climate change towards increasing air temperatures throughout Europe will foster such extreme events, leading to the population being more exposed to them and societies becoming more vulnerable. Based on two climate change scenarios (Representative Concentration Pathway 4.5 and 8.5) we analysed the frequency and intensity of heat waves for three capital cities in Europe representing a North–South transect (London, Luxembourg, Rome). We used indices proposed by the Expert Team on Sector-Specific Climate Indices of the World Meteorological Organization to analyze the number of heat waves, the number of days that contribute to heat waves, the length of the longest heat waves, as well as the mean temperature during heat waves. The threshold for the definition of heat waves is calculated based on a reference period of 30 years for each of the three cities, allowing for a direct comparison of the projected changes between the cities. Changes in the projected air temperature between a reference period (1971–2000) and three future periods (2001–2030 near future, 2031–2060 middle future, and 2061–2090 far future) are statistically significant for all three cities and both emission scenarios. Considerable similarities could be identified for the different heat wave indices. This directly affects the risk of the exposed population and might also negatively influence food security and water supply.

scholarly journals Projected near-term changes in three types of heat waves over China under RCP4.5

2020 ◽  
Author(s):  
Qin Su
Keyword(s):  
Climate Models ◽  
Heat Waves ◽  
Longwave Radiation ◽  
Ocean Model ◽  
Shortwave Radiation ◽  
Minor Role ◽  
Air Temperatures ◽  
Downward Longwave Radiation ◽  
Near Term ◽  
Projected Changes

<p>The changes in three aspects of frequency, intensity and duration of the compound, daytime and nighttime heat waves (HWs) over China during extended summer (May–September) in a future period of the mid-21<sup>st</sup> century (FP; 2045-2055) under RCP4.5 scenario relative to present day (PD; 1994-2011) are investigated by two models, MetUM-GOML1 and MetUM-GOML2, which comprise the atmospheric components of two state-of-the-art climate models coupled to a multi-level mixed-layer ocean model. The results show that in the mid-21<sup>st</sup> century all three types of HWs in China will occur more frequently with strengthened intensity and elongated duration relative to the PD. The compound HWs will change most dramatically, with the frequency in the FP being 4–5 times that in the PD, and the intensity and duration doubling those in the PD. The changes in daytime and nighttime HWs are also remarkable, with the changes of nighttime HWs larger than those of daytime HWs. The future changes of the three types of HWs in China in two models are similar in terms of spatial patterns and area-averaged quantities, indicating these projected changes of HWs over the China under RCP4.5 scenario are robust. Further analyses suggest that projected future changes in HWs over China are determined mainly by the increase in seasonal mean surface air temperatures with change in temperature variability playing a minor role. The seasonal mean temperature increase is due to the increase in surface downward longwave radiation and surface shortwave radiation. The increase in downward longwave radiation results from the enhanced greenhouse effect and increased water vapour in the atmosphere. The increase in surface shortwave radiation is the result of the decreased aerosol emissions, via direct aerosol-radiation interaction and indirect aerosol-cloud interaction over southeastern and northeastern China, and the reduced cloud cover related to a decrease in relative humidity.</p>

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