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Increased coastal erosion and extreme oceanographic forcing driven by El Niño-Southern Oscillation (ENSO) along the Pacific coast are increasingly receiving concerns. Despite considerable attention, the specific impact of these phenomena on Chinese shorelines, particularly along the South China beaches, remains inadequately understood. To address this gap, this study conducted high-frequency surveys on the Qing'an Bay beach in South China and employ a profile fitting model to refined waterline extraction from monthly satellite images. The goal was to investigate the relationship between high-frequency shoreline changes and interannual climate variability (such as ENSO). The findings indicate that the coastal evolution is intricately linked to a combination of strong wave events, summer storms, winter cold waves, and the amplifying effects of ENSO. During La Niña phase, the sea level in the western Pacific experiences a rise, with associated storms proving particularly destructive to the beach environment, leading to violent oscillations in the coastline. Specifically, in the strong La Niña phases, significant wave heights markedly surpass neutral conditions, precipitating intensified sediment movement. However, it is imperative to recognize that shoreline changes alone do not fully characterize coastal erosion. Assessment must also encompass alterations in beach volume. By calculating beach volume per unit width that accounts for the influence of ENSO variability on the beach, the seasonal characteristics of the beach showed sediment losses in summer and autumn, and gains in winter and spring, which was more obvious during strong La Niña. Additionally, conceptual model analysis reveals that during the La Niña phase, the bay is fully exposed, whereas during the El Niño phase, significant headland sheltering is observed. • A profile fitting model based on field data was developed for accurate shoreline Analysis. • La Niña conditions coupled with Western Pacific storms are more destructive to the study area coasts than El Niño events. • Seasonal beach volume changes dramatically during strong La Niña. • Beach volume losses in exposed zones are higher than headland shadowed zones during La Nina phase. [ABSTRACT FROM AUTHOR]

This article analyzes the relationship between abnormal photovoltaic output events and different weather types based on the output data of distributed photovoltaic stations and meteorological reanalysis data of corresponding time periods using methods such as K-means clustering. The analysis finds that abnormal high output events in photovoltaics are related to high-temperature clear weather brought by stable low-pressure systems, and clear windy cooling weather processes controlled by high pressure. The abnormal low output events of photovoltaics are related to transitional weather processes such as cold waves, cloudy and precipitation free weather, and cloudy and rainy weather processes in low-pressure systems. Building upon this analysis, the study constructs a simple extreme output prediction model and examines the atmospheric circulation anomalies corresponding to extreme output events. Using a January 2023 photovoltaic low-output event as an example, the study validates both the extreme output model based on weather type classification and the subjective weather forecast method based on atmospheric circulation patterns, both of which show potential for improving photovoltaic extreme output predictions. The combination of the two can be used to comprehensively evaluate the photovoltaic extreme output events. • Classification of weather types based on extreme photovoltaic output events. • Subjective prediction method for photovoltaic output based on atmospheric circulation. • A photovoltaic abnormal output model based on weather types. [ABSTRACT FROM AUTHOR]

Extreme climatic conditions, like heat waves or cold spells, associated to high concentrations of air pollutants are responsible for a broad range of effects on human health. Consequently, in the recent years, the question on how urban and peri-urban forests may improve both air quality and surface climate conditions at city-scale is receiving growing attention by scientists and policymakers, with previous studies demonstrating how nature-based solutions (NBS) may contribute to reduce the risk of population to be exposed to high pollutant levels and heat stress, preventing, thus, premature mortality. In this study we present a new modeling framework designed to simulate air quality and meteorological conditions from regional to urban scale, allowing thus to assess the impacts of both air pollution and heat stress on human health at urban level. To assess the model reliability, we evaluated the model's performances in reproducing several relevant meteorological, chemical, and biological variables. Results show how our modeling system can reliably reproduce the main meteorological, chemical, and biological variables over our study areas, thus this tool can be used to estimate the impact of air pollution and heat stress on human health. As an example of application, we show how common heat stress and air pollutant indices used for human health protection change when computed from regional to urban scale for the cities of Florence (Italy) and Aix en Provence (France). [Display omitted] • The WRF-Chem model simulates well the air quality and meteorological variables. • The model is able to correctly reproduce their spatial and temporal variability. • The Gross Primary Productivity comparison with observation data revealed a fair agreement. • Ozone and thermal stress highlight serious risk for population living in Mediterranean region. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two trajectories of impaired thyroid hormone sensitivity are identified. • Heat waves and cold spells are associated with the adverse trajectory. • The effect of heat waves and cold spells increases with frequency, intensity, and duration. • High concentrations of fine particulate matter increase the dangers of heat waves. • Men and elderly patients may be potentially susceptible. The climate change scenario has witnessed an increase in extreme temperature events (ETEs), including heat waves and cold spells, and a heightened occurrence of compounding with fine particulate matter (PM 2.5). However, the impact of this phenomenon on the sensitivity to thyroid hormones (THs) in humans is unclear, especially in a group as specific as schizophrenia. A longitudinal study was constructed using longitudinal measurements of thyroid function in schizophrenia in the Anhui Mental Health Center. The latent growth mixture model was applied to assess the optimal trajectory of change in impaired THs sensitivity. We then used logistic regression to explore associations between heat waves, cold spells, and PM 2.5 with impaired THs sensitivity trajectories in the total population and different gender and age subgroups. Furthermore, the effect of the frequency, intensity, and duration of ETEs in the above associations was explored, as well as an assessment of the interaction between ETEs and PM 2.5. Among 931 participants, we identified two classifications of trajectories of impaired THs sensitivity: "Low-stable" (n = 836, 89.80 %) and "Rise-slight down" (n = 95, 10.20 %). Logistic regression showed significant associations between each additional day of heat waves (≥3 days with temperature thresholds above the 95th percentile) and cold spells (≥3 days with temperature thresholds below the 5th percentile) and "Rise-slight down" trajectory, with odds ratios (95 % confidence intervals) of 1.06 (1.02, 1.10) and 1.19 (1.14, 1.24), respectively, and the strength of this association increased with the intensity and duration of ETEs. Subgroup analyses indicated that the association was more pronounced in males and the age group above 40 years. Furthermore, PM 2.5 was found to interact with heat waves, with high concentrations exacerbating the effects of heat waves. Our findings suggest that mitigating both ETEs and PM 2.5 exposures may bring health co-benefits in preventing thyroid impairment in schizophrenia. [ABSTRACT FROM AUTHOR]

Temperature fluctuations within a bridge deck during a cold wave event can cause severe continuity stresses in structures where movement is restrained. Thermal loads are accounted for using thermal gradients that vary depending on bridge location and cross-sectional geometry. However, the effect of temperature change on material properties, particularly on the coefficient of thermal expansion (CTE) is rarely accounted for in the analysis and design. A review of the literature indicates that the CTE of concrete materials can vary significantly with changes in temperature, especially under freezing conditions, whereas saturated or partly saturated concrete exhibits nonlinear expansion at temperatures below freezing, resulting from effective reversal of the CTE sign. This effect has not been considered in the literature, when investigating thermal actions on bridge decks in cold temperatures. The aim of this study is to analyze, using an advanced nonlinear F.E. platform, the structural response of a prestressed concrete box bridge structure subjected to cold wave events, when considering the effect of temperature on the nonlinearity, the magnitude and the sign of the CTE of concrete. Meteorological data from three historical cold events of different intensity is input in the thermal models to simulate the temperature distribution in the bridge deck; the estimated temperature field was then used in a structural model to determine the resulting thermal stresses. The temperature-dependence and nonlinearity of the CTE is modeled after calibration of the mathematical relationships against published data. The results indicate that this behavior has a significant influence on structural response, highlighting the need for pertinent consideration of its effect in the relevant sections of the bridge codes. • The hysteresis between temperature and concrete thermal strain is modelled. • A thermal structural finite element model of a concrete box girder is developed. • Climate conditions from three cold wave events are used as boundary conditions. • The hysteretic behavior had significant effects on structural performance. • Significant increases were observed in tensile and compressive strains. [ABSTRACT FROM AUTHOR]

Thermal comfort in housing is vital for well-being. Despite hot and humid regions experiencing shorter cold periods compared to heatwaves, vulnerable populations are susceptible to threats from cold snaps. However, existing research overlooks undercooling risks in hot regions during winter. This study examines self-built houses in densely populated, hot and humid areas, mainly occupied by elderly residents. We conducted an on-site measurement recording hourly indoor air temperature, humidity, and black globe temperature during wintertime. Two thermal comfort metrics (aPMV and adaptive regression model) and two resilience metrics (SET degree-hour, Hours of Safety) were used to quantify thermal conditions during cold periods under current and future climate conditions. The results show that undercooling hours in recent years exceed 90 % of wintertime using aPMV index and adaptive regression models. Under future climate scenarios (Representative Concentration Pathways), undercooling hours only decrease by 10 %–25 % from 2020 to 2100 across all metrics. Extreme cold events in 2018 saw SET degree-hours double the thermal resilience threshold, while they pose health risks to the elderly for up to 21 days according to the HOS metrics. This study aims to identify the importance of addressing winter thermal comfort in hot and humid regions and to assess the risk posed by cold snaps to vulnerable populations. By quantifying these risks, the study contributes to better decision-making regarding hot-humid region housing thermal retrofit strategies for architects, engineers, and other stakeholders. • Thermal comfort and resilience metrics are used to assess thermal environment. • In 2011 and 2018, Guangzhou experienced cold snaps lasting more than 10 days. • Exceed 90 % discomfort hour in winter using aPMV and adaptive regression model. • Future climate scenarios saw modest reduction of 10 %–30 % in discomfort hours. • Current thermal resilience took extra 10 days to recover after extreme cold events. [ABSTRACT FROM AUTHOR]

Along with the aggravation of climate change, various weather and climate extreme events (abbreviated as climate extremes) are becoming more frequent. During the transition to the use of clean energy, the power system will show increasingly prominent features such as high ratio of clean energy, high ratio of electrification, and a high proportion of electric and electronic equipment, coupled with summer and winter load peaks. Against this backdrop, this paper studies the impacts of climate extremes on the power system using the Texas power outage as an example, and proposes general adaptation measures to cope with climate extremes. For a start, this paper reviews the power outage in Texas caused by an extreme cold wave across the North America in 2021, and conducts an in-depth analysis of its causes. Then, based on the theoretical framework of disaster risk management, this paper analyzes the weather and climate disaster risks, extreme events, exposure, and vulnerability faced by the power system in the context of climate change and extreme events. Finally, in order to build a new power system, this paper establishes an overall framework for the power system to mitigate and adapt to climate change, and summarizes the key techniques involved in power generation, transmission, distribution, and consumption, as well as key technologies in the fields of power supply, power grid, power load, and energy storage, and the strategies and measures for addressing climate change. [ABSTRACT FROM AUTHOR]

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Recent changes in the Earth's climate have led to renewed interest in extreme cold wave (ECW) events. This study identifies the ECW patterns over the Chinese mainland, their corresponding large‐scale meteorological patterns (LMPs) and their favorable planetary wave patterns over 1961–2015. A self‐organizing map classifies ECWs into northeast, nationwide, northwest–south and Qinghai–Tibetan Plateau clusters. The cold anomalies are primarily contributed by the anomalous wind advecting climatological mean temperature for the leading three clusters, but diabaitic heating for the Qinghai–Tibetan Plateau cluster. The associated LMPs are primarily characterized by a dipole with a positive height anomaly over Siberia and a negative height anomaly extending from Japan to the Iranian Plateau, which displaces southwestward among the four ECW clusters. The LMPs induce anomalous northerly flows extending from the upper troposphere to the near‐surface, which deepen the negative height anomaly southwestward from the East Asian trough and accumulate cold air masses over the key regions within the dipole that are phase‐locked with the LMPs (i.e., baroclinic growth). Such baroclinic growth of the LMP is larger during periods of a planetary wave (wavenumbers 1–5) resembling the Northern Annular Mode (NAM). Meanwhile, the negative (positive) phase of the NAM provides more direct contribution to the LMP of the northeast and nationwide (Qinghai‐Tibetan Plateau) ECW clusters and thus are likely to favor the occurrence of ECWs. The negative phase of NAM‐like planetary waves exhibit a positive trend after the transition year of 1987, and could potentially increase the occurrence frequency of nationwide ECWs. Key Points: The gridded temperature data identify a new extreme cold wave (ECW) cluster over the Qinghai–Tibetan PlateauThe Northern Annular Mode–like daily planetary wave patterns contribute more to the anomalous circulation producing ECWs than othersThe increasing trend of ECW occurrence over the Chinese mainland is attributable to the Northern Annular Mode–like daily planetary wave [ABSTRACT FROM AUTHOR]

This article provides information on flooding in various countries. In Ethiopia, the disaster response commission warns that over 36,000 people in Addis Ababa are vulnerable to floods due to the city's landscape and residents' way of living. In Kenya, China and India have sent aid to help with flood relief efforts. Scotland has pledged financial support to Oxfam and Islamic Relief to assist families affected by flooding. Mozambique has experienced extreme weather events, resulting in deaths, injuries, and damage to homes, schools, and crops. Niger has also been affected by heavy flooding, causing deaths and displacement. Somalia has seen flooding in Beledweyne and the drowning of children near the port city of Marka. South Africa has experienced flooding, tornadoes, and snowfall, resulting in fatalities, evacuations, and the need for donations. South Sudan is preparing for severe flooding and plans to release funds to support affected individuals. The article emphasizes the importance of early warning systems and calls for global action to address climate change. [Extracted from the article]

The eastern sub-Himalayan region of India (which belongs to the Cwa zone in Koppen’s classification) experiences severe cold waves during winter which causes a loss in seed vigor. Though most of the studies on cold stress deal with atmospheric temperatures, the seed vigor is majorly affected by the temperature of the soil. Therefore, the vigor loss of tomato and green gram were investigated under low-temperature stress. The analysis of locally available soil temperature showed a median value of 20.3 ± 0.1 °C. When the seeds were subjected to this temperature in vitro, a loss in vigor (70–75%) was observed. This was due to the reduced fluidity of the membrane which caused electrolyte leakage. In this regard, the indigenous polysaccharides-producing microbes act as an eco-friendly priming agent to recover the lost vigor. However, seed treatment with Bacillus and Pseudomonas strains didn’t affect the germination-related factors but aided in recovering 30–70% of the lost vigor by enhancing the growth of seedlings. The mode of vigor recovery was the production of indole-acetic acid. This approach can be used to quicken the nursery period of tomato and green gram exposed to low soil temperatures prevalent in the sub-Himalyan terai region. [ABSTRACT FROM AUTHOR]

The article focuses on agro-phenological phenomena in spring season in Spain in the year 2021. It highlights the impact of the storm Filomena and cold wave on rainfall and variations in the atmospheric temperature. It also reports on strong frost occurred in April 2021 which affected the Eastern peninsula of Europe and the Balearic Islands.

The article presents the meteorological characteristics of each month of the year in Spain, based on popular sayings. The author, José María Lorente, was an expert in meteorology and published several books on the subject. The article highlights the characteristics of the climate in January, February, March, April, and May, including information on temperatures, rainfall, and specific weather phenomena for each month. It emphasizes that the mentioned characteristics are usually observed in normal years. [Extracted from the article]

South‐East China usually experiences mild winter temperatures but can also be impacted by large‐scale and long‐lasting cold events. Here, we investigate how this category of events has changed during the past 6 decades and why, using both observation and climate model ensembles. We first show that models can reproduce the observed largescale dynamics associated with cold events. A dynamical advection of cold air is mostly responsible not only to trigger cold surges but also we found strong feedback from shortwave radiation, decreasing due to enhanced cloud cover. Recent trends are more difficult to evaluate. Models show a large internal variability and intermodel spread, while observation also indicates large uncertainties in its trend due to high internal variability. Our analysis indicates that even if cold events are likely to have been reduced due to greenhouse gases, trends cannot be attributed with high confidence to any anthropogenic signal alone. However, in the next few decades, the frequency of long‐lasting cold events are expected to quickly reduce due to the emerging greenhouse gases signal and possibly weakening aerosol effect over South‐East China. We also found that most of the trends are due to the change in the mean temperature. Thus, indirectly, there is no clear evidence that the change in cold event frequency is due to a change in the circulation. Key Points: Change in the frequency of cold waves over South‐East China during the past decades is not detectable yetCMIP5 and CMIP6 models can reproduce the observed dynamics of these eventsCold waves are expected to decrease due to the dominant impact of greenhouse gases in the next decades [ABSTRACT FROM AUTHOR]

The article reports on decline in the population of Eider Somateria mollissima in Les Grangettes VD, Switzerland. It mentions that since Switzerland is on the southwestern edge of the Harle Piette wintering area and that the abundance of this species is traditionally linked to the occurrence of cold waves in Europe, impacting the erosion of the wintering numbers in our country with the rarefaction of great frosts. It also informs on the negative impacts of changing global climate on same.

The rate constants for the NCN+NO reaction have been measured by laser photolysis/laser-induced fluorescence technique in the temperature range of 254–353 K in the presence of He (40–600 Torr) and N2 (30–528 Torr) buffer gases. The NCN radical was produced from the photodissociation of NCN3 at 193 nm and monitored with a dye laser at 329.01 nm. The reaction was found to be strongly positive-pressure dependent with negative-temperature dependence, as was reported previously. The experimental data could be reasonably accounted for by dual-channel Rice–Ramsperger–Kassel–Marcus calculations based on the predicted potential-energy surface using the modified Gaussian-2 method. The reaction is predicted to occur via weak intermediates, cis- and trans-NCNNO, in the 2A″ state which crosses with the 2A′ state containing more stable cis- and trans-NCNNO isomers. The high barriers for the fragmentation of these isomers and their trapping in the 2A′ state by collisional stabilization give rise to the observed positive-pressure dependence and negative-temperature effect. The predicted energy barrier for the fragmentation of the cis-NCNNO (2A′) to CN+N2O also allows us to quantitatively account for the rate constant previously measured for the reverse process CN+N2O→NCN+NO. [ABSTRACT FROM AUTHOR]

It is argued that anthropogenic global warming may decrease the global occurrence of cold waves. However, a historical record-extreme cold wave, popularly called the "boss level" cold wave, attacked East Asia in January 2016, which gives rise to the discussion of why this boss-level cold wave occurred during the winter with the warmest recorded global mean surface air temperature (SAT). To explore the impacts of human-induced global warming and natural internal atmosphere variability, we investigated the cold-wave-related circulation regime (i.e., the large-scale atmospheric circulation pattern) and compared the observation with the large ensemble simulations of the MIROC5 model. Our results showed that this East Asian extreme cold-wave-related atmospheric circulation regime mainly exhibited an extremely strong anomaly of the Ural blocking high (UBH) and a record-breaking anomaly of the surface Siberian high (SH), and it largely originated from the natural internal atmosphere variability. However, because of the dynamic effect of Arctic amplification, anthropogenic global warming may increase the likelihood of extreme cold waves through shifting the responsible natural atmospheric circulation regime toward a stronger amplitude. The probability of occurrence of extreme anomalies of UBH, SH, and the East Asia area mean SAT have been increased by 58%, 57%, and 32%, respectively, as a consequence of anthropogenic global warming. Therefore, extreme cold waves in East Asia, such as the one in January 2016, may be an enhanced response to the larger internal atmospheric variability modulated by human-induced global warming. [ABSTRACT FROM AUTHOR]

Abstract In this study, we used ground-measured air pollutants and various remote sensing and meteorological datasets to explore the possible causes of the severe particulate matter (PM) pollution episodes of October and November 2015 in Northeast China. The three pollution episodes in different regions were elaborately characterized by analyzing the time variation of PM 2.5 and other pollutants, e.g., CO, NO 2 , and SO 2. The results from MODerate-resolution Imaging Spectrometer (MODIS) revealed that during the study period, dramatic crop residue burning occurred in Northeast China. Combining its time variation and spatial distribution with air pollutants, the crop residue burning was inferred to have a direct influence on the first and second pollution episodes, especially in Heilongjiang Province. Since a cold wave swept Northeast China beginning on 4th November, the PM pollutants were assumed to be transported southward. This assumption was further verified by the backward and forward trajectory models. Additionally, the suddenly increased relative humidity beginning on 7th November and the week of no wind after the cold wave also greatly contributed to the most severe pollution of Liaoning and Jilin on approximately 8th November. Lastly, we compared air quality indexes and pollutants from remote sensing with ground-measured datasets; the results indicated that there were certain correlations and spatial consistency between the two types of datasets, except for UVAI, which is meaningful to the area without an effective ground monitoring network. Highlights • Both ground-measured and remote sensing datasets are used for PM pollution analysis. • Effective method to extract crop residue burning spots from MODIS was used. • Crop residue burning contributed to the pollution episode in Northeast China. • Meteorological conditions have been taken into consideration. • Various factors jointly induced the worst PM pollution episode in November 2015. [ABSTRACT FROM AUTHOR]

Abstract Although heat and cold temperatures are known to have an impact on cattle mortality, no study has evidenced and quantified the influence of the prolonged exposure to extreme temperatures beyond the single effect of daily temperatures. We defined a heat (or cold) wave by a continuous variable indicating the number of successive days with temperatures above (or below) a given threshold. For heat wave, the threshold was set to the 95th or 99th percentile of the mean daily temperature distribution and for cold wave to the 1st or 5th percentile. We collected female cattle mortality data by type of production and age classes between 2001 and 2015 for 100 iso‐hygro‐thermal areas in France. We used time-series analyses to estimate the area-specific heat wave- and cold wave-mortality relationships. Then, we applied meta-analyses to pool area-specific effects at the country level for each definition of heat and cold wave. For each type of production and age classes, our models predicted symmetrical relationships between temperature and mortality, with a temperature range of minimum mortality located approximately between 15 and 20 °C THI in most categories. Outside that range, relative risks between 1.3 and 2.5 were estimated for extreme cold temperatures and relative risks between 1.1 and 1.5 were estimated for extreme hot temperatures depending on age categories and production type. Our results indicated that a prolonged exposure to high (or low) temperatures caused a significant increase on mortality (up to 40% during heat waves and 23% for cold waves, depending on type of production and age classes), in addition to the effect of extreme temperature alone. This additional mortality risk increased along with the duration and intensity of the exposure. Our results suggest that not discriminating the effect of the prolonged exposure to extreme temperature, may overestimate the effect of temperature alone on mortality. Highlights • Heat and cold waves have an impact on cattle mortality, beyond the single effect of extreme temperatures. • Intensity and duration of heat and cold waves increase cattle mortality. • All age and production types are affected, though at different levels. [ABSTRACT FROM AUTHOR]

Air masses in marine cold air outbreaks (CAOs) at high latitudes undergo a remarkable diabatic transformation because of the uptake of heat and moisture from the ocean surface, and the formation of precipitation. In this study, the fundamental characteristics of the water cycle during an intense and persistent, yet archetypal basinwide CAO from Fram Strait into the Nordic seas are analyzed with the aid of the tracer-enabled mesoscale limited-area numerical weather prediction model COSMO. A water budget of the CAO water cycle is performed based on tagged water tracers that follow moisture picked up by the CAO at various stages of its evolution. The atmospheric dynamical factors and boundary conditions that shape this budget are thereby analyzed. The water tracer analysis reveals a highly local water cycle associated with the CAO. Rapid turnover of water vapor results in an average residence time of precipitating waters of about one day. Approximately one-third of the total moisture taken up by the CAO falls as precipitation by convective overturning in the marine CAO boundary layer. Furthermore, precipitation efficiency increases as the CAO air mass matures and is exposed to warmer waters in the Norwegian Sea. These properties of the CAO water cycle are in strong contrast to situations dominated by long-range moisture transport that occur in the dynamically active regions of extratropical cyclones. It is proposed that CAOs in the confined Nordic seas provide a natural laboratory for studying local characteristics of the water cycle and evaluating its representation in models. [ABSTRACT FROM AUTHOR]

Cold-air incursions across South America present a variety of problems, sometimes by advancing to the Amazon basin and causing agricultural losses related to extreme low-temperature events. The synoptic conditions that produce cold-air incursions are relatively well understood; however, the most affected region depends on the route by which cold air spreads across the continent. Therefore, the classification of extreme cold-air incursions allows a better understanding of the particularities directly related to the aforementioned losses. In this work, similarities and differences among extreme cold surges were found through time series correlation of anomaly temperatures in four selected areas and compositing techniques from ERA-Interim reanalysis datasets, resulting in three distinct patterns: meridional penetration (MP), meridional restriction (MR), and east penetration (EP). The patterns identified here enable a more detailed understanding of the synoptic patterns and forcing mechanisms associated with extreme cold-air incursions and therefore can be used for operational weather forecasting. [ABSTRACT FROM AUTHOR]

The present paper proposes to highlight the evolution of the generating factors of the cold wave, which from February 25 to March 2, expanded from the northern and northeast of the European continent and affected much of it, including the Romanian geographic space. After a relatively warm winter as thermal aspect, with an ephemeral snow cover in the low relief areas, the last decade of February and the beginning of March, it creates the classic pattern for a genuine winter episode in Romania. Its location in the contact area between an anti-cyclonic field centered on northern and northeastern Europe and a cyclone in the south-east of the continent will facilitate in the first phase the transport of cold air. Then another factor climatic risk, was of interest, namely the blizzard, with the classic area of manifestation in the south, southeastern and eastern Romania. The thermobaric coupling made in this way ensures severe weather conditions, but normal for the cold season. Besides these triggering factors, it is important to mention the risks induced and associated with this severe weather episode, causing damage to agricultural crops, communication routes, to society in general and to the entire environment, affecting the quality of life as a whole. Special attention will be given to another phenomenon, which followed the cold wave, namely the freezing rain. The practical applicability of the study carried out in operative activity, as well as its actuality, consists in the fact that it is a useful support material, referring to an issue as alarming, as normal for the temperate climate zone during the cold season. [ABSTRACT FROM AUTHOR]

ABSTRACT Zhou, C.Y.; Xu, C.Y.; Zhang, J.S.; Fu, X.Y., and Yin, Y., 2018. Coastal hazards caused by different extreme storms in the Bohai Sea, China. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 816–820. Coconut Creek (Florida), ISSN 0749-0208. The Bohai Sea, a semi-enclosed epicontinental sea, suffers different storms frequently, mainly tropical cyclones in summer/autumn and cold waves in winter/spring. The extreme storms can cause severe coastal hazards such as flooding, coastal structures and ocean platforms failures. A numerical model is set up for the Bohai Sea using MIKE21 with coupled hydrodynamic and wave modules. Observed data of water levels, velocities and wave are used to make model calibration. Based on this model, three typical tropical cyclones and cold waves are simulated. Then the major characteristics of summer tropical cyclones and winter cold waves are discussed. Affected by the tropical cyclone, the water levels of Laizhou Bay and Bohai Bay increase and that of Liaodong Bay decreases. Influenced by the cold wave coupled with an extratropical cyclone, the water levels of Laizhou Bay and Bohai Bay decrease firstly and then increase, which is contrary to the variation trend of water level at Liaodong Bay. Under the single cold wave weather, the water level increases at Laizhou Bay, decreases at Liaodong Bay, and firstly increases then decreases at Bohai Bay. The maximum of surge level caused by cold wave coupled with extratropical cyclone is smaller than that induced by tropical cyclone and single cold wave weather. [ABSTRACT FROM AUTHOR]

Previous studies examining future changes in heat/cold waves using climate model ensembles have been limited to grid cell-average quantities. Here, we make use of an urban parameterization in the Community Earth System Model (CESM) that represents the urban heat island effect, which can exacerbate extreme heat but may ameliorate extreme cold in urban relative to rural areas. Heat/cold wave characteristics are derived for U.S. regions from a bias-corrected CESM 30-member ensemble for climate outcomes driven by the RCP8.5 forcing scenario and a 15-member ensemble driven by RCP4.5. Significant differences are found between urban and grid cell-average heat/cold wave characteristics. Most notably, urban heat waves for 1981–2005 are more intense than grid cell-average by 2.1 °C (southeast) to 4.6 °C (southwest), while cold waves are less intense. We assess the avoided climate impacts of urban heat/cold waves in 2061–2080 when following the lower forcing scenario. Urban heat wave days per year increase from 6 in 1981–2005 to up to 92 (southeast) in RCP8.5. Following RCP4.5 reduces heat wave days by about 50 %. Large avoided impacts are demonstrated for individual communities; e.g., the longest heat wave for Houston in RCP4.5 is 38 days while in RCP8.5 there is one heat wave per year that is longer than a month with some lasting the entire summer. Heat waves also start later in the season in RCP4.5 (earliest are in early May) than RCP8.5 (mid-April), compared to 1981–2005 (late May). In some communities, cold wave events decrease from 2 per year for 1981–2005 to one-in-five year events in RCP4.5 and one-in-ten year events in RCP8.5. [ABSTRACT FROM AUTHOR]

With climate change leading to more frequent, more intense, and longer durations of extreme weather events such as heat waves and cold snaps, it is essential to maintain safe indoor environmental conditions for occupants during such events, which may coincide with, or even cause, power outages that expose residents to health risks. Analyzing the impacts of extreme weather events on the thermal resilience of buildings can help stakeholders (including occupants) understand the risk and inform them about mitigation and adaptation actions. Moreover, analyzing the technological, social and policy dimensions of thermal resilience is critical for climate-proofing buildings. This paper presents 10 questions that highlight the most important issues regarding the thermal resilience of buildings for occupants in the face of climate change. The proposed questions and answers aim to provide insights into current and future building thermal resilience research and applications, and more importantly to inspire new significant questions in the field. • Climate change and extreme weather events pose growing health risks to building occupants. • Metrics, methods, and a simulation workflow for evaluating thermal resilience of buildings are discussed. • Passive design, low-energy systems, backup power, and human behavior interventions are essential for resilient buildings. • Supportive policies are needed to regulate thermal resilience requirements and incentivize stakeholders. • Multidisciplinary approaches are needed to address various aspects of thermal resilience. [ABSTRACT FROM AUTHOR]

Studying extreme events and how they evolve in a changing climate is one of the most important current scientific challenges. Starting from complex climate models, a key difficulty is to be able to run long enough simulations to observe those extremely rare events. In physics, chemistry, and biology, rare event algorithms have recently been developed to compute probabilities of events that cannot be observed in direct numerical simulations. Here we propose such an algorithm, specifically designed for extreme heat or cold waves, based on statistical physics. This approach gives an improvement of more than two orders of magnitude in the sampling efficiency. We describe the dynamics of events that would not be observed otherwise. We show that European extreme heat waves are related to a global teleconnection pattern involving North America and Asia. This tool opens up a wide range of possible studies to quantitatively assess the impact of climate change. [ABSTRACT FROM AUTHOR]

The heating energy consumption per floor area (HECPA) and heating degree days (HDD) are effective indicators in quantifying the energy demand for heating with climate change. Using the heating energy consumption and meteorological data, an attempt has been made to analyse the relationship between the HECPA and HDD in different regions of northern China by the linear regression model. Based on the constructed model, the effects of one cold wave on heating energy consumption in different regions are evaluated. The results show that the HECPA and HDD in Beijing have a positive correlation with a correlation coefficient of 0.68. During the cold wave in 2016, the heating energy consumption in Beijing approximately increases 2.37% compared with 2014. However, no correlation has been found between the HECPA and HDD in the relatively undeveloped regions. It seems that the cold wave has a greater effect on the developed regions than relatively undeveloped ones. It is considered that the reasons for the little effect of one cold wave on heating energy consumption in the undeveloped regions are outdated heating systems, insufficient energy supply for heating and low living standards. [ABSTRACT FROM AUTHOR]

In the present study, a back-propagation neural network model (BP model) was developed with the aim of predicting the sea ice spatial evolution in Liaodong Bay. In addition to air temperature and wind speed, two new variables wind direction and wind duration were used to train the BP model. Validation of the BP model with measurements showed that the BP model can effectively predict the spatial evolution of sea ice. The sensitivity studies indicated that wind direction and wind duration can obviously improve the prediction accuracy of sea ice edge in heavy ice years. Moreover, the BP model was easy to set up as it only used four yearlong periods, 2003–2004, 2005–2006, 2006–2007 and 2009–2010, and the results were not very sensitive to the training dates over the four years. The BP model results were not very sensitive to the training algorithms as well. By comparison with a least-square-based method (LSM), the BP model clearly outperformed the LSM during the period of ice melt with nonlinear characteristics caused by the frequent appearance of cold waves. Furthermore, the BP model had a higher accuracy in estimating the spatial evolution of sea ice compared with a logit model, especially for the ice edge, which is more easily affected by the complex ocean environment. [ABSTRACT FROM AUTHOR]

Extreme cold waves (ECWs) occurring over the conterminous United States (US) are studied through a systematic identification and documentation of their local synoptic structures, associated large-scale meteorological patterns (LMPs), and forcing mechanisms external to the US. Focusing on the boreal cool season (November-March) for 1950-2005, a hierarchical cluster analysis identifies three ECW patterns, respectively characterized by cold surface air temperature anomalies over the upper midwest (UM), northwestern (NW), and southeastern (SE) US. Locally, ECWs are synoptically organized by anomalous high pressure and northerly flow. At larger scales, the UM LMP features a zonal dipole in the mid-tropospheric height field over North America, while the NW and SE LMPs each include a zonal wave train extending from the North Pacific across North America into the North Atlantic. The Community Climate System Model version 4 (CCSM4) in general simulates the three ECW patterns quite well and successfully reproduces the observed enhancements in the frequency of their associated LMPs. La Niña and the cool phase of the Pacific Decadal Oscillation (PDO) favor the occurrence of NW ECWs, while the warm PDO phase, low Arctic sea ice extent and high Eurasian snow cover extent (SCE) are associated with elevated SE-ECW frequency. Additionally, high Eurasian SCE is linked to increases in the occurrence likelihood of UM ECWs. [ABSTRACT FROM AUTHOR]

Cold and heat waves represent a significant problem for the electricity generation sector. The disruptions cold and heat waves can cause in power production are beyond their consumption impacts through, for instance, higher peak demand. Unexpected stops at thermal or nuclear power plants by excessively high-temperature water constitute clear examples of this. In this invited paper, we use past case studies to analyze the impact of these kinds of events on power production. Subsequently we discuss how events of this nature may evolve over the future in view of their association to climate change. Although the review is not exhaustive, we do expose some ideas that may be relevant for decision making in this area. [ABSTRACT FROM AUTHOR]

The paper demonstrates a dependency between the annual average daily air temperature course (cycle) in Warsaw and the profile of annual solar activity linked to rotation (with a period of 25-31 days). Waves of cold (ΔT <0) or heat (ΔT≥ 0) were defined as ΔT deviations of daily average temperature (T) using a regression sinusoid f (t) with a period of 365 days. Cold waves were found to generally occur at times of low daily average solar activity (relative to 60-year average), while hot waves tended to coincide with high Wolf numbers. The cycles of the variables were derived using the sinusoid regression method (Boryczka 1998). The maximum sinusoid regression of the annual air-temperature cycle T is delayed by nearly one month vis-à-vis the maximum declination of the Sun. The maximum of the regression sinusoid of daily average Wolf numbers (W) was delayed from the maximum declination by more than two months. [ABSTRACT FROM AUTHOR]

Periods of successive extreme heat and cold temperature have major effects on human health and increase rates of health service utilisation. The severity of these events varies between geographic locations and populations. This study aimed to estimate the effects of heat waves and cold waves on health service utilisation across urban, regional and remote areas in New South Wales (NSW), Australia, during the 10-year study period 2005-2015. We divided the state into three regions and used 24 over-dispersed or zero-inflated Poisson time-series regression models to estimate the effect of heat waves and cold waves, of three levels of severity, on the rates of ambulance call-outs, emergency department (ED) presentations and mortality. We defined heat waves and cold waves using excess heat factor (EHF) and excess cold factor (ECF) metrics, respectively. Heat waves generally resulted in increased rates of ambulance call-outs, ED presentations and mortality across the three regions and the entire state. For all of NSW, very intense heat waves resulted in an increase of 10.8% (95% confidence interval (CI) 4.5, 17.4%) in mortality, 3.4% (95% CI 0.8, 7.8%) in ED presentations and 10.9% (95% CI 7.7, 14.2%) in ambulance call-outs. Cold waves were shown to have significant effects on ED presentations (9.3% increase for intense events, 95% CI 8.0-10.6%) and mortality (8.8% increase for intense events, 95% CI 2.1-15.9%) in outer regional and remote areas. There was little evidence for an effect from cold waves on health service utilisation in major cities and inner regional areas. Heat waves have a large impact on health service utilisation in NSW in both urban and rural settings. Cold waves also have significant effects in outer regional and remote areas. EHF is a good predictor of health service utilisation for heat waves, although service needs may differ between urban and rural areas. [ABSTRACT FROM AUTHOR]

Based on daily minimum temperature data during 1979-2013, the frequency of occurrence,the beginning date and ending date and other characteristic values of cold waves at all levels are processed. Then, by using the method of Mann-Kendall method, correlation analysis, empirical orthogonal function and Morlet wavelet analysis, the spatiotemporal distribution and inter-annual variation and other characteristics of cold wave, strong cold wave and ultra-strong cold wave of Shandong Province are analyzed. The tendency of cold waves at all levels in Shandong Province is predicted for the coming years, which might be referable in the prevention of cold wave and storm surge disaster. [ABSTRACT FROM AUTHOR]

A combined reed bed-freezing bed (RB-FB) technology was effective at treating septage under Canadian climatic conditions over a 5-year period with average loading rates of 82-104 kg TS/m2/y. Varying hydraulic and solid loading rates as well as the increasing sludge cake with time had little to no effect on treatment efficiency, with almost complete removal of organic matter, solids, heavy metals and nutrients. Filtrate concentrations varied significantly between the freeze-thaw and growing seasons for many parameters, although the differences were not important from a treatment or reuse perspective with filtrate quality similar to a low to medium strength domestic wastewater. The potential to reuse the filtrate as a source of irrigation water will depend upon local regulations. The dewatered sludge cake consistently met biosolids land application standards in terms of pathogen and metals content, with Escherichia coli numbers declining with time as sludge cake depth increased. A combined RB-FB technology can provide a cost-effective solution for septage management in northern rural communities with potential for beneficial reuse of both the filtrate and dewatered sludge cake. [ABSTRACT FROM AUTHOR]

Winter 2016-2017 was normal from the thermal viewpoint, with a general mean value of -1.4°C for the area with altitudes below 600 m, although December 2016 was thermally normal. The winter was marked by the months December, thermally normal but dry, and January, which was cold, displaying a mean value of -5.07°C for the entire region, value that made it the fifth coldest January month in the last 57 years. In December 2016, between the 6th and the 12th (7 days), it was registered the first heat wave of the winter. Two cold waves of 10 days each (January 7-16 and January 20-29) marked January and, in spite of the fact that there were not registered absolute thermal records, the frosty days and nights and the continuous cold produced casualties and triggered an energy crisis during this month. In February, the weather warmed continuously starting with the 2nd and, in the interval February 21-28, it was also registered a moderate heat wave. Climatic warming is well-emphasized even in January, although it was a cold month. The analysis of the temperature mean values calculated for the entire region highlight the decrease of the intensity of the cold waves registered during the winter peak month and a well-marked upward tendency of this parameter. All winter months were dry. The warming occurred in February had important effects on biotopes, crops and fruit trees determining an early spring arrival. The paper is part of a series of extensive studies on climate variability in south-western Romania and the effects of climate warming. The paper is useful for all those interested in the climate evolution in this part of Romania. [ABSTRACT FROM AUTHOR]

The temperature and electric field induced phase instability were found to produce distinctly different temperature-dependences of small- and high-field strains in the proximity of orthorhombic (O) to tetragonal (T) polymorphic phase transition of (Na,K)(Nb,Sb)O 3 -LiTaO 3 lead-free ceramics. As evidenced by means of in-situ and ex-situ synchrotron x-ray diffraction and quantitative analyses, both O-T phase coexistence and intermediate monoclinic (M c ) phase were believed to promote intrinsic piezoelectric strains. Further increase of high-field strains with temperature was ascribed to enhanced contributions from field-induced reversible M c -T phase transition, plus little extrinsic contribution from non-180° domain switching which was unexpectedly hindered near the phase boundary. [ABSTRACT FROM AUTHOR]

Extreme temperature anomalies such as heat and cold waves may have strong impacts on human activities and health. The heat waves in Western Europe in 2003 and in Russia in 2010, or the cold wave in South-Eastern Europe in 2012, generated a considerable amount of economic loss and resulted in the death of several thousands of people. Providing an operational system to monitor extreme temperature anomalies in Europe is thus of prime importance to help decision makers and emergency services which are responsive to an unfolding extreme event. In this study, the development and the validation of a monitoring system of extreme temperature anomalies are presented. The first part of the study describes the methodology based on the persistence of events exceeding a percentile threshold. The method is applied to three different observational datasets, in order to assess the robustness and highlighting uncertainties in the observations. The climatology of extreme events from the last 21 years is then analysed to highlight the spatial and temporal variability of the hazard and discrepancies amongst the observational datasets are discussed. In the last part of the study, the products derived from this study are presented and discussed regarding previous studies. The results highlight the accuracy of the developed index and the statistical robustness of the distribution used to calculate the return periods. [ABSTRACT FROM AUTHOR]

In this study, analysis of heat transfer in a longitudinal rectangular fin with temperature-dependent thermal conductivity and internal heat generation was carried out using finite difference method. The developed systems of non-linear equations that resulted from the discretization using finite difference scheme were solved with the aid of MATLAB using fsolve . The numerical solution was validated with the exact solution for the linear problem. The developed heat transfer models were used to investigate the effects of thermo-geometric parameters, coefficient of heat transfer and thermal conductivity (non-linear) parameters on the temperature distribution, heat transfer and thermal performance of the longitudinal rectangular fin. From the results, it shows that the fin temperature distribution, the total heat transfer, and the fin efficiency are significantly affected by the thermo-geometric parameters of the fin. Also, for the solution to be thermally stable, the fin thermo-geometric parameter must not exceed a specific value. However, it was established that the increase in temperature-dependent properties and internal heat generation values increases the thermal stability range of the thermo-geometric parameter. The results obtained in this analysis serve as basis for comparison of any other method of analysis of the problem. [ABSTRACT FROM AUTHOR]