Cold Season Research Articles

Cold-Season Precipitation Trend in Subtropical East Asia Tied to Shifting Westerlies: Role of Tibetan Plateau

Abstract Precipitation in the late cold season (February–April) over subtropical East Asia (STEA) exhibits a negative trend from 1979 to the present, primarily due to weakening ascent motion. This study investigates the mechanism of weakening ascent over STEA and identifies the poleward-shifting westerlies as a key driver. On an interannual time scale, a poleward shift of the westerlies leads to weakened southern branch westerlies (SBW) on the southern side of the Tibetan Plateau (TP), which further leads to a weaker downstream southerly wind component over STEA, associated with weaker ascent motion generated by isentropic upglide of the southerly flow. During the post-1979 epoch, the SBW shows a substantial weakening trend in the late cold season as a regional manifestation of the planetary-scale poleward-shifting westerlies, which suppresses the ascent motion over STEA and accounts for more than half of the decreasing precipitation over STEA in the late cold season. TP plays a key role in connecting SBW to the southerly flow and ascent motion over STEA in the cold season, and the absence of weakening SBW also explains the absence of a drying trend over STEA in the early cold season. External forcing leads to a moderate poleward shift of planetary-scale westerlies in the entire cold season based on climate model simulations, but it cannot explain the seasonality and magnitude of the observed trend in SBW. Decadal-scale internal variability may have largely boosted the poleward-shifting westerlies in the late cold season but offset it in the early cold season.

Association between short-term ambient NO2 and type 2 diabetes outpatient visits: a time series study in multi-city, China.

As a common chronic disease, type 2 diabetes mellitus (T2DM) and its complications not only jeopardize the health of patients but also impose a heavy economic burden on society and patients' families. Nevertheless, there is a scarcity of evidence regarding the effects of nitrogen dioxide (NO2) on T2DM. In our study, daily data for T2DM outpatients, air pollutants and meteorological factors from January 1, 2018, to December 31, 2020 were collected in three cities: Dingxi, Tianshui and Longnan, an inland province of northwest China. Generalized additive model (GAM) with quasi-Poisson regression combined with the Distributed Lag Non-linear Model (DLNM) were employed to assess the associations between NO2 and daily T2DM outpatients, as well as their lag effects in various cities. We also stratified by gender, age, and season. The results from DLNM revealed that NO2 was significant positively associated with the increase of the number of outpatient visits for T2DM at individual single-day and all cumulative lag days in three cities, with the largest Relative Risk (RR) at lag05, lag05 and lag07 [RR = 1.106 (95%CI: 1.045,1.171) for Dingxi, RR = 1.095 (95%CI: 1.047,1.146) for Tianshui and RR = 1.015 (95%CI: 1.015,1.138) for Longnan]. Stratified analysis of gender, age, and season suggested that the harmful effect of NO2 was greater for males, young people (< 65 years old), and the cold season. In brief, ambient NO2 was associated with the increase in the number of outpatient visits for T2DM in three cities. Our findings suggest that the role of exposure to NO2 in T2DM pathogenesis should be further investigated in China.

Missing incidents and the risk of harm in persons living with dementia reported to the Swedish police– A nationwide retrospective registry study

BackgroundThe number of persons living with dementia is increasing globally, including in Sweden, and these persons are at heightened risk of going missing and coming to harm. When they do go missing, the police get involved. There is a dearth of knowledge surrounding the prevalence and outcomes of harm in these instances in many countries, including Sweden, which affects our understanding of the associated risks and necessary interventions. Therefore, the aim of this study was to describe incidents of missing people and explore factors associated with harm in persons living with dementia as reported to the Swedish Police.MethodsData on background characteristics, the missing incidents, and police response was collected from a nationwide police registry. The missing incidents were analysed using descriptive statistics and logistic regression was used to explore factors associated with harm.ResultsA total of 1,041 missing person case reports concerning persons living with dementia were identified. In 61 (6%) of these reports, the missing person was harmed. The level of harm varied from lacerations to death. Male sex, no prior missing incidents, cold season, time since last contact, delayed reporting, and prolonged duration of police search effort were significantly associated with an increased probability of harm.ConclusionsPersons living with dementia constituted a substantial proportion of all missing persons case reports submitted to the Swedish Police during the study period. Persons living with dementia were also at considerable risk of harm when missing, as even minor injuries can lead to substantial consequences. Furthermore, time was a critical factor, emerging as the strongest predictor of harm in the study. This calls for the development of collaborative routines between the police and professional caregivers caring for persons living with dementia.

Gut bacterial and fungal communities of François’ langur (Trachypithecus francoisi) changed coordinate to different seasons

IntroductionFrançois’ langur (Trachypithecus francoisi), an endangered primate endemic to limestone forests in Vietnam and China, relies on gut microbiota to maintain gastrointestinal stability and adapt to dietary shifts. While gut microbial communities are dynamic and sensitive to seasonal and resource variations, their specific responses in François’ langurs remain poorly characterized. This study investigates seasonal variations in the composition and diversity of gut bacterial and fungal communities in this species to enhance understanding of its ecological adaptations.MethodsFresh fecal samples from 22 François’ langurs in Mayanghe National Nature Reserve, China, were collected across four seasons. Bacterial and fungal communities were analyzed using high-throughput sequencing to assess taxonomic composition and α-diversity. Statistical comparisons were conducted to evaluate seasonal differences at phylum and genus levels.ResultsSignificant seasonal shifts occurred in both bacterial and fungal communities. Bacterial α-diversity peaked in warmer seasons, whereas fungal diversity was higher in colder months. At the genus level, Akkermansia (1.3% relative abundance in summer), a mucin-degrading bacterium linked to gut health, dominated warmer seasons. In contrast, the fungal genus Cercophora, associated with plant biomass degradation, was enriched during colder seasons. Seasonal factors strongly influenced microbial structure, with distinct community assemblages observed across all seasons.DiscussionThe inverse diversity patterns of bacterial and fungal communities suggest complementary roles in nutrient extraction under seasonal dietary constraints. Akkermansia’s summer prevalence may reflect enhanced mucin utilization during fruit-rich periods, while Cercophora’s cold-season dominance likely aids cellulose breakdown in leaf-heavy diets. These dynamics highlight the microbiota’s role in optimizing energy harvest from seasonally variable diets. By elucidating microbial seasonal plasticity, this study provides critical insights for developing conservation strategies tailored to the nutritional ecology of François’ langurs.

Characterizing Seasonal Patterns, Gas-Particle Partitioning, and Potential Sources of Airborne Per- and Polyfluoroalkyl Substances in Japan.

The global ubiquity of perfluoroalkyl and polyfluoroalkyl substances (PFAS) highlights the important role of atmospheric transport. This study monitored 47 PFAS, including perfluoroalkyl acids (PFAAs), emerging PFAS, and precursors of PFAAs (pre-PFAAs), in seasonal ambient air in Japan between 2022 and 2023, quantifying 38 of them in collected samples. The profiles were dominated by 6:2 fluorotelomer alcohol, perfluorobutanesulfonic acid, and perfluorobutanoic acid, with median levels of 245, 117, and 78.0 pg m-3, respectively. Pre-PFAS and perfluoroalkyl carboxylic acids (PFCAs) exhibited relatively higher concentrations in the warm seasons, whereas perfluoroalkyl sulfonic acids (PFSAs) were more abundant in the cold seasons. Particle-bound fractions of PFCAs with carbon number (Cn) ≤ 13 and PFSAs with Cn ≤ 8 were found at lower levels than in previous reports. Additionally, an odd-even pattern in the gas-particle distribution ratio was observed for PFCAs, with relatively higher values for odd-numbered compounds than for their even-numbered counterparts. Using positive matrix factorization analysis, aqueous film-forming foam-related activities, waste stream emissions, and fluoropolymer manufacturing were proposed as potential major sources in the studied areas, with their relative contribution quantified. These findings enhance our understanding of the atmospheric behavior of PFAS and facilitate the development of tailored PFAS mitigation strategies.

Experimental warming effects on microbial community growth and mortality during the cold season in coastal waters of Taiwan and Japan

Experimental warming effects on microbial community growth and mortality during the cold season in coastal waters of Taiwan and Japan

Nitrogen utilization dynamics in a tropical estuary: Interplay of temperature and phytoplankton communities.

Nitrogen utilization dynamics in a tropical estuary: Interplay of temperature and phytoplankton communities.

Atmospheric black carbon (BC) in Hangzhou, China: Temporal variation, source apportionment, and case study of the 19th Asian Games.

Atmospheric black carbon (BC) in Hangzhou, China: Temporal variation, source apportionment, and case study of the 19th Asian Games.

Association between air pollution and hospitalization for acute exacerbation of kidney failure: A nationwide time-stratified case-crossover study in China.

Association between air pollution and hospitalization for acute exacerbation of kidney failure: A nationwide time-stratified case-crossover study in China.

Effects of low temperature on rhizosphere phosphate-mineralizing microbial populations in constructed wetlands.

Effects of low temperature on rhizosphere phosphate-mineralizing microbial populations in constructed wetlands.

The change in weather types in two population centers in northwestern Iran (Urmia and Tabriz) around Lake Urmia with the Woś classification approach

ABSTRACT In order to recognize the effect of the drying up of Lake Urmia on the climate, using the Woś classification method, the types of weather of the two cities of Tabriz and Urmia, were determined during 1980–2018. Then, eight weather types in the range of hot weather types without rain to cool and very cold weather types with low cloudiness and no precipitation showed an occurrence frequency of more than 61%. The highest number of weather types with 45 types in the cold season and 26 types in the hot season was determined in Tabriz and Urmia, respectively. Then, modified Mann–Kendall (MMK) and Sen's slope estimator tests were used to determine the changing trend of the weather types. Investigations showed that, the hot weather type without precipitation and the slightly cool weather type without precipitation and of course without clouds had an increasing trend respectively, and the cold types also showed a decreasing trend in favor of cool types. The intensity of these changes is much greater in Tabriz. In addition, using the Mann–Kendall test, it was also determined that the increasing trend of hot weather in Tabriz started in 2000 at the same time as the lake began to dry up.

Indoor Radon Monitoring in Residential Areas in the Vicinity of Coal Mining Operations in the Mpumalanga Province, South Africa

Coal mining and combustion have the potential to increase exposure to radon, a form of radioactive gas recognized as one of the major contributors to lung cancer incidents. In South Africa, coal is used as the primary energy source for producing electricity and for heating, predominantly in informal settlements and township communities. Most of the existing coal-fired power plants are found in the Mpumalanga province. This paper presents long-term radon (222Rn) measurements in dwellings surrounding coal mining centres in the Mpumalanga province and evaluates their contributions to indoor radon exposures. The indoor radon measurements were conducted using solid-state nuclear track detectors and were performed during warm and cold seasons. It was found that the overall indoor radon activity concentrations ranged between 21 Bq/m3 and 145 Bq/m3, with a mean value of 40 Bq/m3. In all the measured dwellings, the levels were below the WHO reference level of 100 Bq/m3 and 300 Bq/m3 reference level recommended by the IAEA and ICRP, with the exception of one dwelling that was poorly ventilated. The results reveal that individuals residing in the surveyed homes are not exposed to radon levels higher than the WHO, ICRP, and IAEA reference levels. The main source influencing indoor radon activity concentrations was found to be primarily the concentration of uranium found in the geological formations in the area, with ventilation being an additional contributing factor of radon levels in dwellings. To maintain good air quality in homes, it is recommended that household occupants should keep their dwellings well ventilated to keep indoor radon levels as low as possible.

Повышение качества городской среды за счет использования трансформатора теплоты сезонного действия в системах теплоснабжения

The urban economy includes a large number of construction sites for various purposes that need reliable and efficient heat supply, and improvement of infrastructure. And at the same time, they must create a safe and comfortable urban environment. The most important state task of rational use of energy resources can be solved using secondary energy resources and renewable energy sources. Therefore, the development of new modern technologies for the secondary use of energy resources in the urban environment is an urgent task. The purpose of the study is to evaluate the energy and economic efficiency of the proposed seasonal heat transformer, designed to maintain road surfaces of various structures during the cold season without ice and snow cover, as well as to produce hot water in hot water supply systems by utilizing the heat of heating the road surface during the warm season. The method of balance calculations of heat exchange processes in technological power plants is used in the study. A device based on heat transformation processes has been proposed to improve the quality of the urban environment. The efficiency of the proposed device and the operating costs of its operation are determined. The proposed technical solution ensures a reduction in energy costs for buildings and energy savings, and also improves the operational parameters, convenience and safety of the adjacent territories.

Atmospheric deposition of chromophoric dissolved organic matter in the Athabasca Oil Sands Region, Canada, is strongly influenced by industrial sources during the winter months.

Atmospheric deposition of chromophoric dissolved organic matter in the Athabasca Oil Sands Region, Canada, is strongly influenced by industrial sources during the winter months.

Evaluation of Combined Use of Protein and Postbiotics Feed Supplements in Honey Beehives in Autumn and Spring.

Feed supplementation in beehives is a commonly necessary practice in beekeeping today, to address the many risks the honey bees face, mainly the climate change and times of food scarcity, agricultural pesticides, or pathogens such as Varroa destructor or Nosema ceranae. Protein supplements and postbiotics products have been evaluated in beehives feed, obtaining improvements of the strength and sanitary status, but they have not been tested in combination. In this study, two experiences have been carried out in autumn and spring to check the potential beneficial effect of this combination in the beehives. Two monitoring were carried out, before and after 1month of the application of products, in order to assess the strength (number of bees, amount of brood, brood survival, and pollen/honey reserves) and sanitary status (V. destructor and N. ceranae infestation levels) of the colonies. Firstly, the results obtained in autumn experience showed a reduction of both pathogens in supplemented group. On the other hand, in spring, the combination of protein and postbiotics enhanced the brood survival and honey yield, and decreased the V. destructor infestation. Thus, the combined use of protein and postbiotics as feed supplements could be an important tool to improve the sanitary status after the cold season, and to increase the strength and production of beehives in spring, unifying the benefits of both supplements.

Short-term attributable risk and economic burden of hospital admissions for anxiety disorders due to air pollution: a multicity time-stratified case-crossover study

BackgroundAnxiety disorders are a leading cause of severe quality of life impairment and are among the most common mental disorders globally. However, few studies have investigated the association between exposure to high levels of air pollution and an increased risk of developing anxiety disorders. This study aimed to investigate the relationship between air pollutants and hospitalisation for anxiety disorders and the associated economic burden of these hospitalisations in Sichuan, China.MethodsWe collected 7,282 records of anxiety disorder hospitalisation from medical institutions across nine cities between January 1, 2017, and December 31, 2018. Concurrent meteorological and air pollution data, including temperature, humidity, PM2.5, PM10, SO2, and CO, were obtained from 183 monitoring stations in Sichuan Province. After controlling for long-term trends, day of the week, and meteorological factors, we employed a time-stratified case-crossover design based on conditional logistic regression to assess the association between concentrations of the four pollutants (PM2.5, PM10, SO2, and CO) and hospital admissions for anxiety disorders, with stratified analysis by age, sex, and season. The cost of hospitalisation was evaluated using the cost-of-illness method.ResultsThe finding indicated a positive correlation between short-term exposure to air pollutants and hospitalization rates of anxiety disorders. The effect of each 10 µg/m3 increase in airborne particulate matter (PM) and SO2 on hospital admissions for people with anxiety disorders peaked with a lag of 5 days, and each 1 mg/m3 increase in CO had the greatest effect on the 0–7 day moving average lag, with OR values of PM2.5:1.002 (95% CI: 1.001,1.004), PM10:1.001 (95% CI: 1.000,1.002), SO2:1.034 (95% CI: 1.020,1.047), and CO: 1.614 (95% CI: 1.247, 2.089). Air pollution increases the chances of anxiety disorders during the cold season. Furthermore, the elderly are particularly susceptible to these pollutants, which may contribute to an increased hospitalization rates of anxiety disorders (P < 0.05). The total economic cost of hospitalisation for anxiety disorders due to particulate matter pollution was ¥ 966,319 during the study period.ConclusionShort-term exposure to PM2.5, PM10, SO2, and CO may increase the risk of hospital admissions for anxiety disorders and impose significant financial burdens.

A comparative analysis of three PM2.5 exposure metrics and their impact on respiratory disease hospitalizations in Lanzhou, China.

Research on the associations between PM2.5 and total respiratory diseases (RD) in Lanzhou is limited. We investigated the short-term impact of PM2.5 on total RD hospitalizations in Lanzhou (2015-2019) using various exposure metrics. We collected data on hospitalizations, daily air pollutant concentrations, and meteorological factors during the study period. Daily excessive concentration hours (DECH) were calculated according to the World Health Organization's air quality guidelines. A distributional lag nonlinear model (DLNM) based on a generalized additive model (GAM) was used to comparatively analyze the association between three PM2.5 exposure metrics (DECH (DECH PM2.5), daily mean concentration (Mean PM2.5), and hourly peak concentration (Peak PM2.5)) and RD hospitalizations. Subgroup analyses and sensitivity analyses were also performed. We found similar effects on RD hospitalizations using DECH PM2.5 and Mean PM2.5, but relatively weak associations observed using Peak PM2.5. The cumulative lag effect increased daily. Subgroup analyses showed that females and children aged 0-17years were more susceptible to PM2.5 pollution and that the association was enhanced during the cold season. Our research strengthened the evidence that exposure to ambient PM2.5 increases the risk of RD. This study revalidated the reliability of the new metrics and confirmed that DECH PM2.5 effect estimates for exposure-disease were more accurate than the Mean PM2.5.

Study on the Optimal Construction Time of Adjacent Pile Foundation Considering the Thermal Stability of the Existing Pile Foundation

To control settlement deformation in permafrost regions, new piles are constructed for remediation. However, the construction of new piles inevitably causes thermal disturbance to the existing pile foundations. A three-dimensional quarter-model of a rectangularly arranged pile group was established to analyze temperature field changes under construction time in odd-numbered months. In addition, a refreezing rate formula based on the effective freezing temperature was developed to examine the annual changes. The results indicate that the thermal disturbance from the new pile foundation construction gradually weakens over time but does not subside within a year, which significantly affects 75% of the existing pile length, and that the refreezing rate continues to increase after construction in November, i.e., the initial month of the cold season, and is maximized in approximately 60 days. This result suggests that November is the optimal time for such construction activities. The findings of this study provide valuable insights for pile engineering practices to mitigate issues caused by permafrost degradation.

Examining future changes in coastal low-level jet properties offshore California through dynamical downscaling

Abstract The coastal low-level jet, or coastal low-level jet (CLLJ), is a synoptically-forced meteorological feature frequently present offshore the western United States (U.S.). Characterized by a wind speed maximum that resides at the top of the marine boundary layer, the CLLJ is largely controlled by the location and strength of the North Pacific High (NPH) as well as the coastal geometry. Considering the rich wind resource available in this offshore region, the Bureau of Ocean Energy Management identified wind energy lease areas offshore California and supported the deployment of two U.S. Department of Energy wind lidar buoys near Morro Bay and Humboldt. Despite our relatively good understanding of the fundamental mechanisms responsible for large-scale CLLJ properties offshore the western U.S., future changes in CLLJ characteristics are less clear. To address this research challenge, and ultimately to better inform future wind turbine deployments, we use simulations driven by three global climate models (GCMs). We apply self-organizing maps to the model outputs for a historical and two future climate periods to show the range of NPH regimes that support CLLJ conditions during the warm seasons, as well as the subtle contribution from land-falling cyclones approaching the mainland during the cold seasons. Compared to the historical period, the three GCM-driven simulations agree that CLLJ conditions will become more (less) prevalent from central California northward (southward). They agree less with respect to future changes in maximum CLLJ wind speeds and CLLJ heights. However, after considering model biases present during the historical period, wind speeds between the models are actually more similar during the 2070–2095 period than during the historical period. The potential combination of more frequent CLLJ conditions characterized by relatively consistent wind speeds occurring at lower heights across northern California suggests that the Humboldt lease area may be ideal for a long-term wind turbine deployment.

Diversity and eco-epidemiology of ectoparasites and Rickettsia spp. associated with the opossums Didelphis albiventris Lund in livestock farms from Argentinian Pampas region.

Many ectoparasite species serve as vectors for bacteria that are significant to both public and animal health, with wild, domestic and synanthropic mammals acting as reservoirs. However, limited information exists on the circulation and incidence of these vectors in Argentina. We examined the diversity, prevalence and abundance of ectoparasites, along with the presence of Rickettsia spp., of Didelphis albiventris Lund (Didelphimorphia, Didelphidae) within a rural landscape of the Pampas region, Argentina. We also analysed variations in ectoparasite populations concerning seasonality, livestock farm type and farmers' management practices. Seven species of hematophagous ectoparasites were collected, including mites (Mesostigmata, Laelapidae: Laelaps echidninus Berlese); ticks (Ixodida, Ixodidae: Ixodes loricatus Neumann); fleas (Siphonaptera, Rhopalopsyllidae: Polygenis platensis Jordan and Rothschild and Polygenis rimatus Jordan); Stephanocircidae: Craneopsylla minerva wolffhuegeli (Rothschild, Pulicidae: Ctenocephalides felis Bouché); and lice (Phthiraptera, Polyplacidae: Polyplax spinulosa Burmeister). Additionally, two bacteria were detected: Rickettsia felis Bouyer et al. (Rickettsiales, Rickettsiaceae) and Rickettsia sp. (Rickettsiales, Rickettsiaceae) were closely related to Rickettsia bellii Philip et al. (Rickettsiales, Rickettsiaceae). Fleas were the most prevalent and abundant group, with C. felis showing the highest values of mean abundance and prevalence. Parasitological comparisons between dairy farms and feedlots revealed similar results, with comparable densities of D. albiventris in both farm types. Ectoparasite abundance varied seasonally, peaking during the colder season. Regression analysis indicated higher ectoparasite infestation levels on farms with more dogs. The detection of pathogenic bacteria, coupled with the high prevalence and abundance of vectors, such as C. felis, suggests a significant epidemiological risk in the region. The commensal behaviour of D. albiventris facilitates it to thrive in areas modified by anthropogenic activity, positioning this species as a potential nexus between wild and domestic epidemiological cycles of parasites and emerging pathogens. Therefore, our findings suggest that D. albiventris plays a key role in the transmission and maintenance of ectoparasites and ectoparasite-borne bacteria within these ecosystems.