Heat Waves Research Articles

The role of antecedent southwest summer monsoon rainfall on the occurrence of premonsoon heat waves over India in the present global warming era

The role of antecedent southwest summer monsoon rainfall on the occurrence of premonsoon heat waves over India in the present global warming era

Heat Waves and Adverse Health Events Among Dually Eligible Individuals 65 Years and Older

ImportanceExtensive research has found the detrimental health effects of heat waves. However, a critical gap exists in understanding their association with adverse health events among older dually eligible individuals, who may be particularly susceptible to heat waves.ObjectiveTo assess the association between heat waves and adverse health events among dually eligible individuals 65 years and older.Design, Setting, and ParticipantsThis retrospective time-series study assessed the association between heat waves in warm months from 2016 to 2019 and zip code tabulation area (ZCTA)–day level adverse health events. Dually eligible individuals 65 years and older who were continuously enrolled in either a Medicare fee-for-service plan or a Medicare Advantage plan with full Medicaid benefits from May to September in any given year were identified. All ZCTAs in the US with at least 1 dually eligible individual in each study year were included. Data were analyzed from September 2023 to August 2024.ExposureHeat waves, defined as 3 or more consecutive extreme heat days (ie, days with a maximum temperature of at least 90 °F [32.2 °C] and in the 97th percentile of daily maximum temperatures for each ZCTA during the study period).Main Outcomes and MeasuresDaily counts of heat-related emergency department visits and heat-related hospitalizations for each ZCTA.ResultsThe study sample included 5 448 499 beneficiaries 65 years and older in 28 404 ZCTAs across 50 states and Washington, DC; the mean (SD) proportion of female beneficiaries and beneficiaries 85 years and older in each ZCTA was 66% (7%) and 20% (8%), respectively. The incidence rate for heat-related emergency department visits was 10% higher during heat wave days compared to non–heat wave days (incidence rate ratio [IRR], 1.10; 95% CI, 1.08-1.12), and the incidence rate of heat-related hospitalizations was 7% higher during heat wave days (IRR, 1.07; 95% CI, 1.04-1.09). There were similar patterns in other adverse health events, including a 4% higher incidence rate of death during heat wave days (IRR, 1.04; 95% CI, 1.01-1.07). The magnitude of these associations varied across some subgroups. For example, the association between heat waves and heat-related emergency department visits was statistically significant only for individuals in 3 of 9 US climate regions: the Northwest, Ohio Valley, and the West.Conclusions and RelevanceIn this time-series study, heat waves were associated with increased adverse health events among dually eligible individuals 65 years and older. Without adaptation strategies to address the health-related impacts of heat, dually eligible individuals are increasingly likely to face adverse outcomes.

Integrated spatial prioritization of urban nature-based solutions for climate adaptation, mitigation, and justice

ABSTRACT In densely populated cities, people confront multiple impacts of climate change, including stormwater runoff, flooding, heat waves, and health issues. To address these impacts, nature-based solutions (NbS) have gained significant attention in recent years due to their potential to contribute to sustainability, resilience, and ecosystem services. Nevertheless, more research is required to understand the wider potential of NbS and to identify priority areas for their deployment. This study developed an analytical approach and implemented it in the Tehran Metropolitan Area (TMA) by considering factors related to NbS co-benefits. The approach included spatial prioritization, spatial correlation analysis, and suitability analysis. It combines a Geographic Information System, Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, Zonation, Best-Worst Method, Bivariate Local Indicator of Spatial Autocorrelation analysis (BiLISA), a Fuzzy Inference System, and Boolean overlay analysis. The results include maps showing priority areas for different types of NbS and spatial co-benefits and mismatches. High-priority areas are located in disadvantaged areas. In total, 105.73 km2 (17% of the TMA) was designated as highly prioritized. We show that various NbS interventions are applicable, with green roofs and rainwater harvesting being the most feasible. This study can assist decision-makers in optimizing NbS to deliver maximum co-benefits.

The Alarming Risks for Dually Eligible Beneficiaries During Heat Waves

The Alarming Risks for Dually Eligible Beneficiaries During Heat Waves

Large eddy simulation of the combined effect of heat fluxes and wave forcing of summer monsoon on a diurnal ocean mixed layer in the north Arabian Sea

Large eddy simulation of the combined effect of heat fluxes and wave forcing of summer monsoon on a diurnal ocean mixed layer in the north Arabian Sea

Changes in duration and intensity of waves of heat and cold on the territory of Belarus over the period from 1955 to 2021

The impact of modern climate warming on the characteristics of heat and cold waves on the territory of Belarus has been analysed. Since 1988, the number of heat waves and strong thaws has significantly increased (less than 15% of all registered heat waves and strong thaws occurred in the pre-warming period of 1955–1987), while the number of frost and summer cold waves has decreased. The average duration of frost and summer cold waves has decreased by 0.5–1.5 days, the average duration of strong thaws has increased by 1 day, while the changes in the duration of heat waves have been less significant. The greatest changes in temperature have been observed for strong thaws and frost waves (increase of up to 0.8°C). Heat waves are characterized by a decrease in the average duration by 1 day and the smallest temperature changes, because due to increase in average values, summer temperatures got closer to thresholds for a heat wave. Despite the effect of modern warming, frost waves remain the most intense type of extreme temperature episodes in Belarus. The spatial distribution of temperatures during heat and cold waves is either uniform or determined by seasonal temperature gradients.

Zinc oxide nanoparticles cooperate with the phyllosphere to promote grain yield and nutritional quality of rice under heatwave stress

To address rising global food demand, the development of sustainable technologies to increase productivity is urgently needed. This study revealed that foliar application of zinc oxide nanoparticles (ZnO NPs; 30 to 80 nm, 0.67 mg/d per plant, 6 d) to rice leaves under heatwave (HW) stress increased the grain yield and nutritional quality. Compared with the HW control, the HWs+ZnO group presented increases in the grain yield, grain protein content, and amino acid content of 22.1%, 11.8%, and 77.5%, respectively. Nanoscale ZnO aggregated on the leaf surface and interacted with leaf surface molecules. Compared with that at ambient temperature, HW treatment increased the dissolution of ZnO NPs on the leaf surface by 25.9% and facilitated their translocation to mesophyll cells. The Zn in the leaves existed as both ionic Zn and particulate ZnO. Compared with the HW control, foliar application of ZnO NPs under HW conditions increased leaf nutrient levels (Zn, Mn, Cu, Fe, and Mg) by 15.8 to 416.9%, the chlorophyll content by 22.2 to 24.8%, Rubisco enzyme activity by 21.2%, and antioxidant activity by 26.7 to 31.2%. Transcriptomic analyses revealed that ZnO NPs reversed HW-induced transcriptomic dysregulation, thereby enhancing leaf photosynthesis by 74.4%. Additionally, ZnO NPs increased the diversity, stability, and enrichment of beneficial microbial taxa and protected the phyllosphere microbial community from HW damage. This work elucidates how NPs interact with the phyllosphere, highlighting the potential of NPs to promote sustainable agriculture, especially under extreme climate events (e.g., HWs).

Contrasting responses of commercially important Northwest Atlantic bivalve species to ocean acidification and temperature conditions

Modern calcifying marine organisms face numerous environmental stressors, including overfishing, deoxygenation, increasing ocean temperatures, and ocean acidification (OA). Coastal marine settings are predicted to become warmer and more acidic in coming decades, heightening the risks of extreme events such as marine heat waves. Given these threats, it is important to understand the vulnerabilities of marine organisms that construct their shells from calcium carbonate, which are particularly susceptible to warming and decreasing pH levels. To investigate the response of four commercially relevant bivalve species to OA and differing temperatures, juvenile Mercenaria mercenaria (hard shell clams), juvenile Mya arenaria (soft shell clams), adult and juvenile Arctica islandica (ocean quahog), and juvenile Placopecten magellanicus (Atlantic sea scallops) were grown in varying pH and temperature conditions. Species were exposed to four controlled pH conditions (7.4, 7.6, 7.8, and ambient/8.0) and three controlled temperature conditions (6, 9, and 12°C) for 20.5 weeks and then shell growth and coloration were analyzed. This research marks the first direct comparison of these species’ biological responses to both temperature and OA conditions within the same experiment. The four species exhibited varying responses to temperature and OA conditions. Mortality rates were not significantly associated with pH or temperature conditions for any of the species studied. Growth (measured as change in maximum shell height) was observed to be higher in warmer tanks for all species and was not significantly impacted by pH. Two groups (juvenile M. arenaria and juvenile M. mercenaria) exhibited lightening in the color of their shells at lower pH levels at all temperatures, attributed to a loss of shell periostracum. The variable responses of the studied bivalve species, despite belonging to the same phylogenetic class and geographic region, highlights the need for further study into implications for health and management of bivalves in the face of variable stressors.

Diverging Projections of Future Droughts in High‐End Climate Scenarios for Different Potential Evapotranspiration Methods: A National‐Scale Assessment for Poland

ABSTRACTIt has been broadly reported that future climate change will most likely affect the spatio‐temporal distribution of water resources and consequently droughts. There is a prevailing notion that an increase in temperature and frequency of heat waves are expected to result in more intense droughts in the coming years. In this study, we aimed to evaluate the effect of the potential evapotranspiration (PET) method selection on future drought projections over Poland. In our study, simulations of the Soil and Water Assessment Tool (SWAT) model were conducted, utilising an ensemble of six EURO‐CORDEX projections, spanning the period from 2006 to 2100 under the RCP8.5 scenario. Two model setups with two different PET methods (Penman‐Monteith—PM and Hargreaves—HAR) were used. For drought conditions evaluation we selected the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for meteorological drought, Standardized Streamflow Index (SSI) for hydrological drought, and Standardized Soil Moisture Index (SMI) for agricultural drought. The meteorological and hydrological droughts were calculated using a 12‐month time aggregation window, while agricultural drought was calculated using a 3‐month window. Climate projections revealed that by 2080s annual mean temperature and precipitation increase is expected by up to +3.4°C and +10.3% respectively. Under future climate conditions duration and severity of meteorological droughts are projected to decrease. PM method leads to a higher PET increases (1.35 mm year−1) than the HAR method (1.1 mm year−1) throughout the century which entail diverging signal of change for agricultural and hydrological droughts. PM‐ and HAR‐based simulations indicate increase in the total duration and cumulative severity of agricultural droughts, buthowever, for HAR‐based projections, the increase is much less. For hydrological droughts the signal of change is similar for both PET methods, but considerably distinct in magnitude. Considering the entire simulation period, by the end of the century cumulative severity of hydrological droughts is projected to decrease, with a much more pronounced decline for HAR (70% reduction) than for the PM method (35% reduction). Our study demonstrated that methodological choices are crucial to the assessment of future drought risk under climate change.

Assessing Land Use and Cover Changes arising from the 2022 water crisis in Southeast China: A comparative analysis of Remote Sensing Imagery classifications and Machine Learning algorithms

Abstract. The water crisis in the southeast region of China in 2022, caused by one of the worst heatwaves on record, was characterized by severe shortages of water resources, leading to challenges for local communities, agriculture, and industry. To analyze changes in land use and land cover (LULC) in the Jialing River region, Chongqing, China, we compared Remote Sensing (RS) imagery classifications before and after the intense heat waves of 2022. We evaluated the performance of two machine learning algorithms, KDTree KNN and Random Forest (RF), in LULC classifications. The classifications were carried out based on the RS images from the OLI/Landsat 8 system, NDWI index, and SRTM data. The model performances were similar, the classification accuracy showed that the RF algorithm was superior to KDTree KNN. The RF LULC classification and area calculation corroborate with the visual analysis, reaffirming the superiority of RF, which shows a decrease in water surface area, unlike DKTree KNN.

A rapid response process for evaluating causes of extreme temperature events in the United States: The 2023 Texas/Louisiana heat wave as a prototype

Abstract As climate attribution studies have become more common, routine processes are now being established for attribution analysis following extreme events. This study describes the prototype process being developed through a collaboration across National Oceanic and Atmospheric Administration (NOAA), including monitoring tools as well as observational and model-based analysis of causal factors. The prolonged period of extreme heat in summer 2023 over Texas, Louisiana and adjacent areas provided a proving ground for this emerging capability. This event posed unique challenges to the initial process. The extreme heat lasted for most of the summer while most heat wave metrics have been designed for 3–7 d events. The eastern portion of the affected area also occurred within the so-called summer-time daytime warming hole where the warming trend in maximum temperatures has been mitigated wholly or in part by increased precipitation. The extreme temperature coincided with a strong—but not record—precipitation deficit over the region. Both observations and climate model simulations illustrate that the temperatures for a given precipitation deficit have warmed in recent decades. In other words, meteorological droughts today are hotter than their historical analogs providing a stronger attribution to anthropogenic forcing than for temperature alone. These findings were summarized in a prototype plain language report that was distributed to key stakeholders. Based on their feedback, the monitoring and assessment tools will continue to be refined, and the project is exploring other climate model large ensembles to increase the robustness of attribution for future events.

Heat waves during egg development alter maternal care and offspring quality in the European earwig

Heat waves during egg development alter maternal care and offspring quality in the European earwig

Impact of 2022 flood on socio-economic and health status of people residing in flood-stricken areas of Pakistan: a cross-sectional survey

Background: The events of extreme weather and climate-related disasters such as drought, flood, and heat waves are increasing worldwide. This paper highlights the impact of the 2022 flood in Pakistan on the socio-economic and health status of people residing in flood-stricken areas of Pakistan. Methodology: A post-flood survey was conducted from three districts of Pakistan with a myriad of questions inquiring about the biopsychosocial aspects of the affected community. Data were collected through a validated questionnaire and was analyzed through SPSS software version 25. Results: Forty percent of people became homeless; the number of individuals with a low income decreased by 9%; and the number of individuals with a moderate income decreased by 22%. Additionally, 48.7% of subjects lost their income due to flooding, 83.4% of subjects reported having some type of illness or disability since the flooding (previously 16.4%), and 92.8% believed that the floods had affected the health and sanitation of their area. Importantly, 22.6% of subjects expressed difficulty in accessing food after flooding compared to before and 59.9% of respondents noted they were unaware of proper pre-flood evacuation protocols in their area. Conclusion: The authors’ study indicates that the floods had a significant impact on the socio-economic and health status of residents, particularly those with lower incomes depriving a large proportion of nutrition, health facilities, and property. Without access to necessities and healthcare, individuals are more vulnerable to illnesses, such as chronic respiratory disease, diabetes, and heart disease. The authors stress the importance of providing infrastructural, nutritional, and medical services support to ensure that a community such as Pakistan can recover and thrive post-environmental disaster.

Unveiling Marine Heatwave Dynamics in the Persian /Arabian Gulf and the Gulf of Oman: A Spatio-Temporal Analysis and Future Projections

Amid escalating global marine heat waves, the Arabian Gulf is critical due to its shallow depths, high temperatures, and vulnerability to climate change impacts. This study provides a detailed spatio-temporal analysis of marine heatwave events from 1982 to 2022 across the Arabian Gulf and the adjacent Gulf of Oman. The study delineates regions of heightened vulnerability within these water bodies by comprehensively analyzing seasonal and annual variabilities and trend assessments. Moreover, an exploration of prevailing surface circulation patterns, underpinned by an extensive study of global circulation model outputs, elucidates the oceanographic mechanisms contributing to temperature dynamics. Identifying 25 significant heat wave events, with a focused examination of the six most protracted episodes, is noteworthy among the findings. Strikingly, the analysis reveals that the Gulf of Oman surpasses the Arabian Gulf in heatwave intensity. Looking forward, the investigation extends to future surface water temperature projections up to the close of the current century. The collective results underscore the region's acute susceptibility to the climate change perturbations of climate change, emphasizing the urgency of targeted interventions to mitigate these effects and address concurrent local stressors.

Exploring experimental tests concerning liquid hydrogen releases

In recent years, the adoption of liquid hydrogen (LH2) has increased significantly in industrial and transport applications, driven by its low carbon footprint, thereby aiding the fight against global warming. Additionally, its high volumetric energy density, compared to gaseous or compressed hydrogen, enhances hydrogen storage capabilities. However, safety remains a major concern due to its physical-chemical properties and inherent hazardous characteristics, especially in the event of spillage scenarios. Therefore, to better understand the consequences of LH2 releases onto or into water, large-scale experimental tests were conducted by Bundesanstalt für Materialforschung und -prüfung (BAM) within the Safe Hydrogen Fuel Handling and Use for Efficient Implementation (SH2IFT) project at the Test Site Technical Safety of BAM, comprising 75 single spill events at varied release rates and orientations. While the rapid phase transition (RPT) phenomenon was not observed, self-ignition of the hydrogen-air cloud occurred, accompanied by blast wave overpressure and heat radiation, without a discernible ignition source. These findings emphasize the need for further investigation into LH2 safety. Leveraging experimental data for real-world applications provides insights into safe LH2 infrastructure implementation, laying foundational knowledge for addressing safety challenges and advancing LH2 technology.

Hyperoxia does not improve the acute upper thermal tolerance of a tropical marine fish (Lutjanus apodus).

Fish can experience hyperoxia in shallow environments due to photosynthetic activity and this has been suggested to provide them with a metabolic refuge during acute warming. However, this hypothesis has never been tested on a tropical marine species. Thus, we fitted 29°C-acclimated wild schoolmaster snapper (Lutjanus apodus; a species known to experience diel hyperoxia in mangrove creeks and coastal waters) with Transonic® flow probes and exposed them to an acute increase in temperature (at 1°Ch-1) in respirometers under normoxia and hyperoxia (150% air saturation), until their critical thermal maximum (CTmax). The CTmax of both groups was ∼39°C, and no differences in maximum cardiac function were recorded as the fish were warmed. However, temperature-induced factorial aerobic scope was significantly greater in fish tested under hyperoxia. These data suggest that hyperoxia will not protect coastal tropical fish species during marine heat waves, despite its effects on metabolic scope/capacity.

Cooling lactating sows exposed to early summer heat wave alters circadian patterns of behavior and rhythms of respiration, rectal temperature, and saliva melatonin.

Heat stress (HS) exerts detrimental effects on animal production, with lactating sows being particularly vulnerable. Understanding the mechanisms involved in HS response could aid in developing effective strategies against the negative impacts on livestock. Recent genome wide association studies identified two core circadian clock genes as potential candidates in mediating HS response. The study aimed to investigate how cooling lactating sows under natural heat stress conditions impacted circadian patterns of respiration rate (RR), rectal temperature (RT), behavior, salivary melatonin and cortisol levels, and diurnal patterns of cytokines in saliva. Mixed parity lactating sows were assigned to one of two treatment groups: electronic cooling pad (C; n = 9) and heat-stressed (H; n = 9). The experiment spanned two 48 h periods of elevated ambient temperatures due to summer heat wave. In the first 48 h period, RR was recorded every 30 min, RT every 60 min, and behaviors (eating, standing, sitting, laying, sleeping, drinking, and nursing) every 5 min. In the second 48 h period, saliva samples were collected every 4 h. Cooling reduced RR and RT and altered circadian patterns (P < 0.05). Cooling did not affect amount of time engaged in any behavior over the 48 h period (P > 0.05), however, daily patterns of eating, standing and laying differed between the treatments (P < 0.05), with altered eating behavior related to RT increment in H sows (P < 0.05). Cooling increased and altered the circadian pattern of salivary melatonin (P < 0.05). Cooling also influenced the diurnal pattern of saliva cytokines. Cooling had no impact on saliva cortisol levels. In conclusion, cooling HS sows impacted circadian rhythms of physiology and behavior, supporting the need for further research to understand if circadian disruption underlies decreased production efficiency of HS animals.

A GIS-Based Framework to Analyze the Behavior of Urban Greenery During Heatwaves Using Satellite Data

This work proposes a new unsupervised method to evaluate the behavior of urban green areas in the presence of heatwave scenarios by analyzing three indices extracted from satellite data: the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Moisture Index (NDMI), and Land Surface Temperature (LST). The aim of this research is to analyze the behavior of urban vegetation types during heatwaves through the analysis of these three indices. To evaluate how these indices characterize urban green areas during heatwaves, an unsupervised classification method of the three indices is proposed that uses the Elbow method to determine the optimal number of classes and the Jenks classification algorithm. Each class is assigned a Gaussian fuzzy set and the green urban areas are classified using zonal statistics operators. The membership degree of the corresponding fuzzy set is calculated to assess the reliability of the classification. Finally, for each type of greenery, the frequencies of types of green areas belonging to NDVI, NDMI, and LST classes are analyzed to evaluate their behavior during heatwaves. The framework was tested in an urban area consisting of the city of Naples (Italy). The results show that some types of greenery, such as deciduous forests and olive groves, are more efficient, in terms of health status and cooling effect, than other types of urban green areas during heatwaves; they are classified with NDVI and NDMI values of mainly High and Medium High, and maximum LST values of Medium Low. Conversely, uncultivated areas show critical behaviors during heatwaves; they are classified with maximum NDVI and NDMI values of Medium Low and maximum LST values of Medium High. The research results represent a support to urban planners and local municipalities in designing effective strategies and nature-based solutions to deal with heat waves in urban settlements.

Neural network based estimates of the climate impact on mortality in Germany: application to storyline climate simulations

The aim of this work is the prediction of heat-related mortality for Germany under future, i.e. hotter, climate conditions. The prediction is made based on 2m temperature data from climate storyline simulations using machine learning techniques. We use an echo state network for linking the outputs of storyline climate simulations to the target data. The target data are all-cause mortality rates of Germany for all ages. The network is trained with present day climate model outputs. Model outputs of future, i.e. 2K and 4K warmer, storylines are used to predict mortality rates under such climatic conditions. We find that we can train an echo state network with recent temperature data and mortality and make plausible predictions about expected developments of mortality in Germany based on future climate storylines. The trained network can successfully predict mortality rates for future climate conditions. We find increased mortality during the summer months which is attributed to the presence of more severe heat waves. The mortality decrease found during winter can be explained milder winters leading to fewer deaths caused by respiratory diseases. However, mortality in winter is largely influenced by other factors such as influenza waves or vaccination rate and explainability due to temperature is limited.

Climate change impact assessment of variations in temperature trends across India: a case study

ABSTRACT Extreme weather events are becoming more severe and frequent worldwide. This study employs the Mann–Kendall test and Thein-Sen estimator for analysing the mean temperature trend in India’s four densely populated metropolitan cities of New Delhi, Kolkata, Mumbai, and Chennai under representative concentration pathways (RCP) 4.5 and 8.5 scenarios. The trend reveals rising temperatures across four Indian regions with the change being more dominant under RCP 8.5 scenario. By the end of the twenty-first century, RCP 4.5 and 8.5 anticipate a significant rise in mean temperature of 6.0°C and 9.0°C in the Western Himalayas, 5.0°C and 7.5°C in East India and 4.0°C and 7.0°C in the Thar Desert’s south-eastern region. Spatio-temporal variation also indicated the influence of heat waves across different regions of India in the late twenty-first century. There should be relevant long-term and short-term policies to mitigate the effect of climate change and optimise the mortality rate caused by heat stress.