Extreme Summer Temperatures Research Articles

The pace of change of summertime temperature extremes

Summer temperature extremes can have large impacts on humans and the biosphere, and an increase in heat extremes is one of the most visible symptoms of climate change. Multiple mechanisms have been proposed that would predict faster warming of heat extremes than typical summer days, but it is unclear whether this is occurring. Here, we show that, in both observations and historical climate model simulations, the hottest summer days have warmed at the same pace as the median globally, in each hemisphere, and in the tropics from 1959 to 2023. In contrast, the coldest summer days have warmed more slowly than the median in the global average, a signal that is not simulated in any of 262 simulations across 28 CMIP6 models. The observed stretching of the cold tail indicates that observed summertime temperatures have become more variable despite the lack of hot day amplification. The interannual variability and trend in the warming of both hot and cold extremes compared to the median can be explained from a surface energy balance perspective based on changes in net surface radiation and evaporative fraction. Tropical hot day amplification is projected to emerge in the future (2024-2099, SSP3-7.0 scenario), while Northern Hemisphere heat extremes are expected to continue to follow the median.

Variations of summer extreme high temperatures over the Indochina Peninsula: Roles of oceanic systems

Utilizing the reanalysis data and model simulations, we explore the interannual variations of extreme high temperatures over the Indochina Peninsula during 1960–2022, as well as their responses to critical oceanic systems and corresponding mechanisms. Given the intricate interactions among oceanic regions, this study employs the Generalized Equilibrium Feedback Analysis method to extract the atmospheric responses to key ocean systems, including the tropical Indian Ocean (TIO), El Niño–Southern Oscillation (ENSO), and tropical Atlantic. Results highlight the significant contributions of TIO and ENSO. It is suggested that the anomalous anticyclonic circulation located over the Indochina Peninsula, as a response to the warm TIO and ENSO, favors the local anomalous downward motions, resulting in reduced cloud cover, diminished precipitation, increased net radiative energy to the surface and increased sensible and latent heat flux from the surface to the atmosphere, and finally inducing an increase in extreme high temperatures. These observed patterns are also well simulated by the Community Earth System Model tropical Indian Ocean and tropical Pacific Ocean pacemaker experiments, indicating that the warmer tropical Indian Ocean and ENSO could induce anomalous anticyclonic (cyclonic) patterns at the lower (upper) troposphere over the South China Sea, thereby promoting the subsidence and occurrence of extreme high temperatures over the Indochina Peninsula.

Sclerochronology of the large scallops Gigantopecten latissimus and Pecten jacobaeus in a Pliocene warmer Mediterranean Sea

Here we apply a sclerochronological approach to reconstruct the life-history of two stenohaline bivalves of the family Pectinidae, Gigantopecten latissimus and Pecten jacobaeus from the Pliocene of Italy. The specimens come from the locality of Torrita di Siena (Siena-Radicofani Basin, Tuscany), dated to the late Zanclean-Piacenzian with nannoplankton biostratigraphy and Sr-isotope stratigraphy. After measuring the width of micro-growth increments and verifying that the shells were not diagenetically altered, we sampled them at high resolution for carbon and oxygen stable isotopes. δ13C and δ18O shell values allowed to distinguish between specimens that lived above or below the thermocline. Those influenced by surface waters indicate temperatures (for δ18Oseawater = 1.5‰) with winter minima of 16–18 °C and summer values up to 28–29 °C, close to present temperature conditions in the tropical west-African climate belt. In line with this, we found that the two species had similar seasonal growth patterns, with faster growth during colder months and summer slowdown, a typical adaptation of bivalves of tropical affinity suffering from summer temperature extremes. Despite this similar adaptation, G. latissimus, with large and heavy shells (length up to 30 cm) became extinct around 3.0 Ma, while the smaller P. jacobaeus survived Plio-Pleistocene cooling. Different growth rates between the two species and, therefore, different metabolic costs, might explain such differential response, together with differences in reproduction strategies. Habitat loss and fragmentation, due to the decrease of shelf margins and organogenic substrates caused by cooling and sea level fall, are abiotic factors that could have also contributed to the extinction of G. latissimus. P. jacobaeus adaptation to live across a larger bathymetric range, which indicates the ability to thrive in a wider range of temperatures, most likely played a role in its survival. Further studies, including more specimens across multiple localities, will help verifying these hypotheses.

Extreme summer temperature anomalies over Greenland largely result from clear-sky radiation and circulation anomalies

The polar regions have been undergoing amplified warming in recent years. In particular, Greenland has experienced anomalously warm summers with intense melt rates. We employ a surface radiation budget framework to examine the causes for positive and negative summer temperature anomaly events over Greenland from 1979 to 2021. We found a dominant contribution of the clear-sky downwelling longwave radiation and the surface albedo feedback to temperature anomalies. Atmospheric temperature perturbations dominate the effect of anomalous emissivity on clear-sky downwelling longwave radiation. In warm years, enhanced turbulent heat exchange due to increased surface temperature and diabatic warming in the troposphere induces adiabatic heating of the atmosphere, enhanced moisture advection, and a high-pressure anomaly with a blocking-like anti-cyclonic circulation anomaly following peak temperature days. Different modes of natural climate variability, in particular, related to blocking over Greenland, can further amplify or dampen the ongoing warming trend, causing extreme temperature events.

A Bayesian hierarchical spatio-temporal model for summer extreme temperatures in Spain

A statistical study was made of the summer extreme temperatures over peninsular Spain in the last forty years. Records from 158 observatories regularly distributed over Iberia with no missing data were available for the common period from 1981 to 2020. For this purpose, a hierarchical spatio-temporal model with a Gaussian copula and a generalized extreme value parametrization of the extreme events was used. The temporal trend in maximum extreme temperatures was studied making use of both a stationary model and a nonstationary one that takes into account the influence of anthropogenic climate change on extreme temperatures using the global mean temperature as a function of time for the study period. The results led to a better fit of the nonstationary model, with there being a 3.5-fold greater increase in the 20-year return level of the extreme temperatures than in that corresponding to the global mean temperature.

Predictability of the anomaly pattern of summer extreme high temperature days over northern China

Predictability of the anomaly pattern of summer extreme high temperature days over northern China

Evaluation of Pre-Analytical Variables for Human Papillomavirus Primary Screening from Self-Collected Vaginal Swabs

HPV primary screening is an effective approach to assessing cervical cancer risk. Self-collected vaginal swabs have shown promise to expand testing access, but there are limited data defining analytical performance criteria necessary for adoption of self-collected specimens, especially for those occurring outside the clinic where the swab remains dry during transport. Here, we evaluated the performance of self-collected vaginal swabs for HPV detection using the Roche Cobas 6800. There was insignificant variability between swabs self-collected by the same individual (n=15 participants collecting 5 swabs/participant), measured by amplification of HPV and human β-globin control DNA. Comparison of self-collected vaginal swab and provider-collected cervical samples (n=144 paired collections) proved highly concordant for HPV detection (total agreement=90.3%;PPA=84.2%). There was no relationship between the number of dry storage days and amplification of HPV (n=68, range 4-41days). Exposure of self-collected dry swabs to extreme summer and winter temperatures did not affect testing outcomes. We assessed a second internal control (RNAseP) in a subset and demonstrate that lack of amplification for β-globin from self-collected specimens was consistent with poor, but not absent, cellularity. These data suggest that self-collected vaginal samples enable accurate clinical HPV testing, and that extended ambient dry storage or exposure to extreme temperatures do not influence HPV detection. Further, lack of β-globin amplification in HPV negative samples accurately identified participants that required recollection.

Thermal adaptation involves higher expression levels of the lethal(2)-essential-for-life-like (l(2)efl) among the honeybee Apis mellifera L. subspecies

Apis mellifera yemenitica is the native honeybee of the Arabian Peninsula. It demonstrates unique morphological, behavioral, and molecular aspects to survive extreme summer temperatures dominating the region. In this study, relative expression of Apis mellifera lethal(2)-essential-for-life-like (l(2)efl) gene family (ID: 724405; 724488; 234274) were measured in A. m. yemenitica and A. m. carnica under desert (Riyadh) and semiarid (Baha) conditions of Saudi Arabia. Results demonstrated significantly higher day-long expression levels of l(2)efl mRNAs in A. m. yemenitica than in A. m. carnica under the same conditions. Under desert conditions of Riyadh, fold changes in expression levels of l(2)efl mRNAs were ∼100× higher in A. m. yemenitica than the calibrator. In Baha (semiarid conditions), l(2)efl expression levels were very modest compared to those in Riyadh with significant interaction between location and subspecies. In conclusion, expression of l(2)efl (mRNAs) (724405; 724488; 234274) can be considered as a key component of A. m. yemenitica response to extreme desert temperatures characterizing the Riyadh region. On the other hand, the semi-arid conditions (Baha) are a more suitable habitat for A. m. carnica compared to Riyadh.

Disentangling the Unprecedented Yangtze River Basin Extreme High Temperatures in Summer 2022: Combined Impacts of the Reintensified La Niña and Strong Positive NAO

Abstract During July and August of 2022, the Yangtze River Basin (YRB) experienced its most extreme high temperature (EHT) event since 1979, resulting in large numbers of human casualties and severe economic losses. This paper reveals the spatial and temporal features of the EHT over the YRB (YRB-EHT) in 2022 and disentangles its extreme nature from a historical perspective. Results showed the following: 1) The record-breaking YRB-EHT was directly caused by the adiabatic heating associated with an anomalous barotropic high pressure (or heat dome) and descending motion in the region. The intensified and westward-shifted western North Pacific subtropical high and eastward-extended South Asian high played critical roles in the formation of the heat dome and descending motion anomaly. 2) Convection anomalies over the tropical Atlantic and Pacific induced by the reintensified La Niña–like Pacific sea surface temperature anomaly pattern, along with the strong positive North Atlantic Oscillation (NAO), were the key contributing factors to the formation of the barotropic high pressure anomaly and YRB-EHT. 3) A physics-based empirical simulation model constructed using the factors of the NAO and tropical convection successfully reproduced the historical year-to-year variation of YRB temperatures, as well as the extreme in 2022, implying that the unprecedented 2022 YRB-EHT had universal dynamic origins. This study highlights the importance of the combined impacts of tropical and extratropical forcings in the record-breaking YRB-EHT in 2022, and thus may provide useful clues for seasonal predictions of summer mean or extreme temperatures in the YRB. Significance Statement Extreme high temperatures hit the Yangtze River Basin (YRB) in summer 2022, causing large numbers of human casualties and severe economic losses. Here, from a historical perspective, we disentangle the dynamic origins of these high temperatures over the YRB. Based on evidence from both observations and model simulations, the present study highlights the importance of the combined impacts of tropical and extratropical routes of influence on these extremely high temperatures in the YRB, and thus may provide useful clues for seasonal predictions of YRB summer mean or extreme temperatures.

A time-varying Copula-based approach to quantify the effects of antecedent drought on hot extremes

Hot extremes may adversely impact human health and agricultural production. Owing to anthropogenic and climate changes, the close and dynamic interaction between drought and hot extremes in most areas of China need to be revisited from the perspective of nonstationarity. This study therefore proposes a time-varying Copula-based model to describe the nonstationary dependence structure of summer extreme temperature (SET) and antecedent soil moisture condition to quantify the dynamic risk of hot extremes conditioned on dry/wet condition. A general statistical inspection procedure which was composed of maximum likelihood (ML)-based estimation, nonstationary Goodness-of-fit (GOF) tests, the log likelihood ratio (LR) tests and minimum corrected Akaike information criterion-based selection was promoted to select the best-fitted nonstationary models efficiently. This study proposed a new approach to identify the soil moisture driving law over extreme temperature from the point view of tail monotonicity and nonstationary risk assessment. Owing to the LTI-RTD (left tail increasing and right tail decreasing) tail monotonicity for dependence structure of these two extremes derived from most areas, two kinds of the driving laws of soil moisture over SET were detected. Because of the spatiotemporal divergence of sensitivity index derived from tail monotonicity (SITM), we can conclude that the spatial and temporal heterogeneity of response degree of ET over the variations of antecedent dry/wet conditions is evident. Incorporation of nonstationarity and tail monotonicity helps identify the changes of driving mechanism (laws) between soil moisture and hot extremes.

Ability of the GRAPES Ensemble Forecast Product to Forecast Extreme Temperatures over the Tibetan Plateau

Due to climate change, extreme temperature events are receiving increased attention. Based on the climate state deviation and threat score (TS), the ability of the Global/Regional Assimilation and Prediction System (GRAPES) ensemble model to forecast extreme temperature events was examined. The “optimal” Extreme Forecast Index (EFI) was derived for plateau forecasting, and its predictability was examined based on the receiver operating characteristic (ROC) curve method. Meanwhile, the applicability of the Shift of Tails (SOT) index to extreme temperature forecasting was analyzed using extreme temperature cases. Results showed that the GRAPES model has a warm bias for both summer extreme high temperature and winter extreme low temperature, and the warm bias decreases slightly with an increase in the forecasting lead time. The ensemble mean and median forecasts are less effective, and the maximum value is more predictable. However, for the ensemble forecast model, the extreme information in its forecast is more unstable, and the limitation of the extreme temperature forecast in the plateau region is higher. With different forecast lead times, the TS tends to increase and then decrease with an increase in the EFI threshold, which means that there is an optimal EFI. The optimal EFI thresholds for summer extreme high-temperature forecasts are all less than −0.5, while for winter extreme low-temperature forecasts, they are almost all less than 0. From the ROC curves, the EFI has a certain level of predictability for summer extreme high temperatures but poorer forecasting effects. Furthermore, the EFI has some predictability for extreme summer high temperatures, but the prediction effect is poor. For the extremely low temperatures in winter, which are poorly predicted by the model itself, post-processing of the extreme information predicted by the model with the EFI can improve the forecasting effect of the model. Through analysis of individual cases, it was found that the extreme intensity reflected by the SOT_+ (0.9) index of the model was closer to reality for the prediction of extremely high temperatures, whereas for the prediction of extremely low temperatures, the extreme intensity indicated by the SOT_− (0.1) index of the model was weaker. Therefore, the SOT index can play an important auxiliary role in the prediction of the intensity of extreme events based on the EFI.

A-056 Data Driven Approach to Ensure Accurate Total Testosterone Results in Consumer Initiated, Home-collected Capillary Samples

Abstract Background Home-collected direct access testing (DAT) has become increasingly attractive as telehealth utilization advances. With DAT, consumers initiate their lab order and have access to clinical consulting staff. Steroid hormone concentrations are uniquely positioned for DAT due to their inherent stability and non-acute indications. Total testosterone (TT) is used to screen for or monitor treatment of hypogonadism. Once diagnosed, testosterone is administered by intramuscular or subcutaneous injection or via transdermal patch or topical gel. TT in adult men is typically between 200 and 900 ng/dL. However, in our DAT lab we were encountering a significant percentage of samples with supraphysiological TT concentrations (>1500 ng/dL). The objective of this study was to design a quality assurance workflow to differentiate whether the supraphysiological results were accurate or erroneous. Methods TT was measured using the Roche Cobas e801 immunoassay; basic assay parameters were verified per general CAP guidelines (precision, accuracy, linearity, method comparison, interferences, carryover, dilution). Additional validation experiments were performed to verify that capillary plasma was an acceptable sample type (n = 30 paired capillary/venous samples) and to determine if extreme summer temperature fluctuations would influence stability (n = 46 participants; samples subjected to temperature cycling for 72 h before re-evaluation). Self-collected capillary samples received for clinical testing with a TT concentration >1500 ng/dL were run on a 1:5 dilution (extending the clinical reportable range to 7500 ng/dL) and the sample was reflexed to luteinizing hormone (LH) and follicle stimulating hormone (FSH). Reference intervals in adult men for LH and FSH are 1.7–8.6 mIU/mL and 1.4–13.0 mIU/mL, respectively. When available, clinical notes were reviewed for additional information on exogenous hormone usage. Results All general assay parameters were within acceptable metrics. TT concentrations between capillary and venous samples had an average absolute bias of −9.2 ng/dL or −3.8% (n = 30; range = <20–823 ng/dL; y = 0.954x + 1.915; R = 0.995). Baseline and post-summer temperature cycling TT concentrations had an average absolute bias of −8.1ng/dL or −3.4% (n = 46; range = <20–716 ng/dL; y = 0.934x + 7.728; R = 0.999). Samples (n = 506) with a TT concentration >1500 ng/dL were reflexed to TT dilution and LH/FSH. Most (n = 413; 82%) had undetectable (<0.3 mIU/mL) LH/FSH and a mean TT concentration of 3356 ng/dL (SD = 1972). For 18.6% (n = 77) of this subset, we had medication information; 68 were using injectable testosterone. Elevated TT was likely a true result caused by overuse of anabolic steroids. A smaller subset of samples (n = 21) had detectable LH/FSH with mean concentration/SD of 6.1/5.2 mIU/mL for LH, 5.3/5.4 mIU/mL for FSH, and TT >7500 ng/dL. Medication notes were available for 5 of these samples and indicated that the TT results were likely caused by topical contamination (false positive). A final subset (n = 40) had detectable LH/FSH and TT between 1500 and 7500 ng/dL. These samples could not be binned into simple categories and instead were sent to the lab director for review. Conclusion Self-collected capillary specimens are acceptable for TT measurements. A quality assurance reflex to LH/FSH can support or refute the validity of supraphysiological results in a consumer initiated/DAT population.

Relationship between the North Atlantic sea surface temperature and the summer extreme high temperature in the Beijing-Tianjin-Hebei region, China

Climate change influence on the economy and environment in the Beijing–Tianjin–Hebei (BTH) region. This study examined the variations of extreme high temperature days (EHDs) over the BTH region in summer during 1982 to 2021. The trend and frequency of EHDs has increased significantly during the last 40 years. The spatial and temporal variations of EHDs also indicate a significant increase by using the rotated empirical orthogonal functions (REOF) method. Furthermore, the singular value decomposition (SVD) method and correlation analysis are used to indicate the relationship between the EHDs in June–July-August (JJA) in the BTH region and North Atlantic sea surface temperature anomalies (SSTA) in the March–April-May (MAM) during 1982–2021. The result shows that there was positive relationship between the North Atlantic SSTA in MAM and the EHDs in JJA in the BTH region. Composite analysis suggests that relationship between EHDs and SSTA are connected by associated atmospheric circulation through the wave activity flux.

Centennial Variation and Mechanism of the Extreme High Temperatures in Summer over China during the Holocene Forced by Total Solar Irradiance

Under the background of global warming, the frequency and intensity of extreme climate have increased, especially extreme high temperatures. In order to correctly predict the changes in the extreme high temperatures in summer in China in this century, it is urgent to deepen the understanding of the characteristics and physical mechanisms of the extreme high temperatures in summer on the centennial timescale. Many researchers have explored the mechanism of the influences of the variability of the solar cycle on climate change, while the mechanism of the influences of the centennial variation of solar activity on climate change remains elusive. Here, we use the outputs from the Control (CTRL) experiment, Total solar irradiance and Orbital (TSI_ORB) experiment, and Orbital (ORB) experiment from Nanjing Normal University-Holocene (NNU-Hol) experiments to study the extreme high temperatures in summer in China during the Holocene. On the basis of verifying the consistency of the centennial period between the TSI (TSI_ORB minus ORB plus CTRL) experiment and the reconstructed data, we compared the centennial variation characteristics of the summer extreme high temperature in the CTRL experiment and the TSI experiment. It shows that under the modulation of total solar irradiance, the centennial spatial pattern of the summer extreme high temperatures changed from dipole mode to uniform mode, with 300-year and 500-year periodicity, compared to the influence of only internal variability. On the centennial time scale, the greatest difference is located in northeast China. The subsidence movement and the reduction of cloud cover caused by the anticyclone under the control of high-pressure lead to the increase of downward solar radiation, thus making a positive center is showed in northeast China on the impacts of total solar irradiance. Furthermore, the center of the Rossby wave train in the barotropic structure of the upper circulation related to the summer extreme high temperature significantly moves northward. This barotropic structure is composed of continuous pressure ridges from Eurasia to North America and the North Atlantic, which is conducive to the increase of the summer extreme high temperatures. Furthermore, we investigated the underlying physical mechanisms. Under the influence of total solar irradiance, the Pacific Decadal Oscillation (PDO) with the same centennial cycle as extreme high temperatures lead to obvious subsidence movement and increase of radiation flux, causing an increase in extreme high temperatures over northeast China.

The impact of extreme summer temperatures in the United Kingdom on infant sleep: Implications for learning and development

The U.S. Global Change Research Program reports that the frequency and intensity of extreme heat are increasing globally. Studies of the impact of climate change on child health often exclude sleep, despite its importance for healthy growth and development. To address this gap in the literature, we studied the impact of unusually high temperatures in the summer of 2022 on infants’ sleep. Sleep was assessed objectively using Nanit camera monitors in infants’ homes. Generally, sleep was not impacted when temperatures stayed below 88° but was negatively impacted when temperatures reached over 100°. Compared to non-heatwave nights, infants had less total sleep, less efficient sleep, took longer to fall asleep, had more fragmented sleep, and parents’ visits were more frequent during the night. Following peaks in temperature, sleep metrics rebounded to better than average compared to non-peak nights, suggesting that infants compensated for disrupted sleep by sleeping more and with fewer interruptions once the temperature dropped below 85°. Increased instances of disrupted sleep in infancy have important implications for psychological health and development. Climate disruptions such as heat waves that create occasional or ongoing sleep disruptions can leave infants vulnerable and unprepared for learning.

Heat Stress: A Serious Disruptor of the Reproductive Physiology of Dairy Cows.

Global warming is a significant threat to the sustainability and profitability of the dairy sector, not only in tropical or subtropical regions but also in temperate zones where extreme summer temperatures have become a new and challenging reality. Prolonged exposure of dairy cows to high temperatures compromises animal welfare, increases morbidity, and suppresses fertility, resulting in devastating economic losses for farmers. To counteract the deleterious effects of heat stress, cattl e employ various adaptive thermoregulatory mechanisms including molecular, endocrine, physiological, and behavioral responses. These adaptations involve the immediate secretion of heat shock proteins and cortisol, followed by a complex network of disrupted secretion of metabolic and reproductive hormones such as prolactin, ghrelin, ovarian steroid, and pituitary gonadotrophins. While the strategic heat stress mitigation measures can restore milk production through modifications of the microclimate and nutritional interventions, the summer fertility records remain at low levels compared to those of the thermoneutral periods of the year. This is because sustainment of high fertility is a multifaceted process that requires appropriate energy balance, undisrupted mode of various hormones secretion to sustain the maturation and fertilizing competence of the oocyte, the normal development of the early embryo and unhampered maternal-embryo crosstalk. In this review, we summarize the major molecular and endocrine responses to elevated temperatures in dairy cows, as well as the impacts on maturing oocytes and early embryos, and discuss the consequences that heat stress brings about in dairy cattle fertility.

Evaluating the quality of street trees in Washington, D.C.: Implications for environmental justice

Urban street trees are part of the bundle of environmental amenities that support healthy social, economic, and environmental functions. In this study, we systematically evaluate the quality of 196,825 street trees at the US. Census tract level in Washington D.C., as well as related impacts from socioeconomic, landscape patterns and environmental factors using Ordinary least-squares (OLS) regression, geographically weighted regression (GWR) and structural equation modeling (SEM). Our results reveal that environmental and socioeconomic factors can explain most of the spatial variation of street tree quality in Washington, D.C. There is a substantial statistical negative relationship between median household income and the percent of street trees under stress, which provided the evidence of the inequities of street tree quality in Washington D.C. Higher-income neighborhoods exhibited a lower proportion of street trees under stress. In addition, the extreme summer temperature is positively associated with the proportion of street trees under stress. The quality of street trees is directly impacted by environmental and landscape pattern factors. There is also an indirect impact from socioeconomic factor toward quality of street trees. Our findings suggest that multiple variables, related to income, age, education, landscape pattern, and environment contribute to the quality of street trees in D.C. Based upon our findings, we identify strategies and insights for urban street tree management in DC to not only address environmental inequity and injustice, but also promote a more inclusive and resilient urban greenery system.

Anthropogenic heat release due to energy consumption exacerbates European summer extreme high temperature

Anthropogenic heat release (AHR) is the release of heat generated by anthropogenic energy consumption. The global mean flux of AHR is 0.03 W m−2, while AHR is geographically concentrated and fundamentally correlates with economic activity; furthermore, AHR can reach a level sufficient for impacting regional even large-scale climate. In this study, the impacts of AHR on the summer European heatwaves (EHWs) are examined by using the Community Earth System Model version 1 (CESM1). The results show that in Europe, AHR increases the summer mean 2-m temperature by 0.26 °C and the surface minimum and maximum temperatures by 0.14 °C and 0.41 °C, respectively. AHR exacerbates the extreme high temperatures in the summer in Europe, increasing EHW days by 1–2 days in central and eastern Europe in the summer annually from 1992 to 2013. AHR strengthens the surface wind that flows from the ocean to the land in Europe by increasing the land surface temperatures. AHR decreases the lower-troposphere stability (LTS) and reduces the low-cloud amounts in Europe, which leads to more solar shortwave radiation reaching the surface. AHR affects water vapor and the surface energy balance in Europe, which impacts on European summer heatwaves further. AHR acts as a non-negligible factor for summer extreme high temperature in Europe and a potential factor impacting EHW days.

Carrying out the demercurization of heavy metals (mercury) using the Denite immobilizer and its effect on the soil

On the territory of the Northern industrial zone of Pavlodar in the area of the industrial wastewater reservoir «Bylkyldak» in some areas of the earth there is soil contamination with mercury, exceeding the MPC for mercury (2.1 mg/kg) by 500 times. The total mass of mercury dispersed in the surface layer of soils is 2.8 tons. The mass of contaminated soil is approximately 208,000 tons. Pollution of the territory is historical. The purpose of the article is to determine the efficiency of chemical binding (immobilization) of mercury in the soil with the Japanese drug Denite® in real field conditions of the territory of mercury contamination in the Northern industrial zone of Pavlodar using an experimental study; to determine the stability of insoluble mercury compounds formed by the preparation at extreme winter and summer temperatures and seasonal fluctuations in open ground. Soil samples were taken for the study at 11 points in the centers of mercury pollution. Laboratory studies were carried out in an accredited analytical laboratory of the Testing Center of JSC Caustic. Soil samples were treated with Denite®, the preparations obtained were stabilized, and water extracts were prepared. The content of mercury in soils, extracts from them, and plants was determined by the atomic absorption method on a RA-915+ spectrometer equipped with RP-91 and RP-91S attachments. As a result of research, the effectiveness of Denite® in the chemical binding of mercury in the soil has been proven and its optimal dosages have been determined. As a result of the positive tests of the technology of chemical immobilization of mercury, the prospect of a practical solution to the issue of demercurization of mercury-contaminated soil on the territory of the Northern industrial zone appeared.

Unprecedented 21st century heat across the Pacific Northwest of North America

Extreme summer temperatures are increasingly common across the Northern Hemisphere and inflict severe socioeconomic and biological consequences. In summer 2021, the Pacific Northwest region of North America (PNW) experienced a 2-week-long extreme heatwave, which contributed to record-breaking summer temperatures. Here, we use tree-ring records to show that summer temperatures in 2021, as well as the rate of summertime warming during the last several decades, are unprecedented within the context of the last millennium for the PNW. In the absence of committed efforts to curtail anthropogenic emissions below intermediate levels (SSP2–4.5), climate model projections indicate a rapidly increasing risk of the PNW regularly experiencing 2021-like extreme summer temperatures, with a 50% chance of yearly occurrence by 2050. The 2021 summer temperatures experienced across the PNW provide a benchmark and impetus for communities in historically temperate climates to account for extreme heat-related impacts in climate change adaptation strategies.