International Journal of Biometeorology最新文献

Heat-health warning systems and services are important preventive actions for extreme heat, however, global evidence differs on which temperature indicator is more informative for heat-health outcomes. We comprehensively assessed temperature predictors on their summer associations with adverse health impacts in a high-density subtropical city. Maximum, mean, and minimum temperatures were examined on their associations with non-cancer mortality and hospital admissions in Hong Kong during summer seasons 2010-2019 using Generalized Additive Models and Distributed Lag Non-linear Models. In summary, mean and minimum temperatures were identified as strong indicators for mortality, with a relative risk(RR) and 95% confidence interval(CI) of 1.037 (1.006-1.069) and 1.055 (1.019-1.092), respectively, at 95th percentile vs. optimal temperature. Additionally, minimum temperatures captured the effects of hospital admissions, RR1.009 (95%CI: 1.000- 1.018). In stratified analyses, significant associations were found for older adults, female sex, and respiratory-related outcomes. For comparison, there was no association between maximum temperature and health outcomes. With climate change and projected increase of night-time warming, the findings from this comprehensive assessment method are useful to strengthen heat prevention strategies and enhance heat-health warning systems. Other locations could refer to this comprehensive method to evaluate their heat risk, especially in highly urbanized environments and subtropical cities.

Terrestrial ecosystems are one of the major sinks of atmospheric CO₂ and play a key role in climate change mitigation. Forest ecosystems offset nearly 25% of the global annual CO₂ emissions, and a large part of this is stored in the aboveground woody biomass. Several studies have focused on understanding the carbon sequestration processes in forest ecosystems and their response to climate change using the eddy covariance (EC) technique and remotely sensed vegetation indices. However, very few of them address the linkage of tree-ring growth with the ecosystem-atmosphere carbon exchange, and nearly none have tested this linkage over a long-term (> 100 years) - limited by the short-term (< 50 years) availability of measured ecosystem carbon flux. Nevertheless, tree-ring indices can potentially act as proxies for ecosystem productivity. We utilise the Coupled Climate Carbon Cycle Model Intercomparison Project (C4MIP) model outputs for its 140-year-long simulated records of mean monthly gross primary productivity (GPP) and compare them with the tree-ring growth indices over the northwestern Himalayan region in India. In this study, we examine three coniferous tree species: Pinus roxburghii and Picea smithiana wall. Boiss and Cedrus deodara and find that the strength of the correlation between GPP and tree ring growth indices (RWI) varies among the species.

With higher temperatures expected in the future due to global climate change, addressing health risks such as heat illness is increasingly important. In Japan, thousands of heat illness cases occur annually during school sports club activities. The risk may vary by sport, location, and region, but how heat safety thresholds (HSTs) should be adjusted to provide effective guidelines remains uncertain. Thus, we conducted a case-crossover study using data of heat illness cases and wet-bulb globe temperature (WBGT) throughout Japan to evaluate the heat illness risk for the current HSTs and propose adjustments. A significant relationship was found between heat illness incidence and WBGT at the time of the incident, as well as the average WBGT one and two days prior. The risk significantly varies with factors such as club, region, location, year, month, and the average WBGT in summer. Therefore, we recommend lowering the current HSTs by one category (3 °C) in the following cases: (1) clubs at high risk (baseball, softball, soccer/futsal, tennis, track and field, kyudo, and other with sustained exercise or thick uniforms); (2) from April to June; (3) in cooler regions (Hokkaido, Tohoku, Hokuriku, or where the average WBGT in summer≦18℃); (4) for outdoor activities; (5) when heat rapidly increases without adequate heat acclimatization. These findings may inform educators, students, sports authorities, and policymakers in adjusting HSTs to reduce the incidence of heat illness, thereby ensuring safer environments for school sports activities.

Heat stress in hyper-prolific lactating sows is recognised as a factor reducing feed intake, milk production, and welfare, with significant losses in farm productivity. Individual capacities for body thermoregulation during environmental hyperthermia determine the adaptation of the animal during long and recurrent events. This study aimed to evaluate the ability of attenuated total reflectance (ATR) mid infrared (MIR) spectroscopy as a high-throughput method to identify markers of stress in plasma and milk collected from lactating sows under heat stress conditions fed with two levels of protein in the diet defined as low (16%) and standard (20%). The MIR spectra were analysed using linear discriminant analysis (LDA) and principal component analysis and validated using cross-validation. The results obtained indicated that MIR spectroscopy, in combination with chemometrics, was able to identify changes in the spectra associated with heat stress in wavenumbers corresponding with amide groups (proteins) (highest loadings observed in the regions between1065 and 1635 cm^-1), lipids and unsaturated fatty acids (regions between 1746 and 3063 cm^-1), lipo-polysaccharides (in 1247 cm^-1) and carbohydrates (around the region1050 cm^-1). These results also indicated that the information provided by these wavenumbers can be used as metabolic markers of the adaptation of the sows to hyperthermia. It was concluded that MIR spectroscopy is a rapid and inexpensive tool capable of detecting and evaluating the main biochemical changes of hyperthermia on lactating sows, facilitating the development of palliative management strategies such as dietary manipulations.

With climate change posing increasing threats and aging populations, understanding the complex relationship between extreme temperatures, PM_2.5 pollution, and respiratory health among the elderly is crucial. While some research exists, there remains a significant gap in studying the combined effects of heat waves, cold spells, and PM_2.5 on elderly respiratory health in high-altitude regions. We collected data from Xining (2016-2021), including respiratory disease outpatient visits, meteorological, and pollutant data. Employing a case-crossover design and conditional Poisson regression analysis, we investigated the individual and interactive impacts of heat wave, cold spell, and PM_2.5 on outpatient visits for respiratory disease among the elderly. We used the relative excess odds due to interaction (REOI), proportion attributable to interaction (AP), and synergy index (S) as quantitative indicators of interaction. Our analysis revealed significant associations between heat wave, cold spell, PM_2.5 exposure, and outpatient visits for respiratory disease among the elderly, with odds ratios of 1.10 (95%CI: 1.06, 1.15) and 1.16 (95%CI: 1.13, 1.20), respectively. Moreover, a synergistic effect between cold spell and PM_2.5 was observed, particularly affecting vulnerable groups such as female and those aged ≥ 80. The combined exposure to cold spell and elevated PM_2.5 levels was estimated to contribute to up to 0.18 (95%CI: 0.17, 0.27) of respiratory outpatient visits. This study underscores the need for urgent interventions, such as reducing PM_2.5 exposure and enhancing extreme weather warning systems, to protect the respiratory health of the elderly, especially in high-altitude regions.

The purpose of this study was to design a local ventilation system (LVS) to help reduce the moisture content of a Scalder hall, evaluate its comfort and thermal stress before and after implementation of LVS and introduce an appropriate index to evaluate warm and humid workplaces. The design of the LVS was performed according to the ACGIH standard (VS-30-01). Heat stress and thermal comfort assessment were performed before and after LVS using humidity index (Humidex), discomfort index (DI), heat index (HI), wet-bulb globe temperature (WBGT) and predicted mean vote index (PMV) indices and the results were compared with predicted mean vote index-predicted percentage of dissatisfied (PMV-PPD) subjective indices. The results of heat stress parameters showed that LVS was able to reduce relative humidity (RH) and wet temperature (t_nw) by 47% and 7 ° C, respectively. This has caused subjects to feel the heat from hot and very RH hot to warm and the hot and percentage of dissatisfaction has dropped by more than 70%. Design and implementation of a LVS reduced the ambient t_nw by decreasing RH. Results also showed in warm and humid workplaces, DI index are highly correlated with subjective evaluation of thermal comfort and this index can be used to evaluate the thermal conditions of the workplaces.

Climate change and growing population and their strain on animal production are the impending challenges that the developing countries, like India, need to tackle in the coming days. This study aimed to detect and analyze the uncharacterized variation in the gene expression patterns with the change of condition, from thermoneutral to chronic hot-humid, in the Sahiwal cattle, one of the best breeds of milk-producing cattle in India, known for being heat-tolerant. Using RNA-Seq analysis on peripheral blood mononuclear cells (PBMCs), 4021 differentially expressed mRNAs (2772 upregulated, 1249 downregulated) and 1303 differentially expressed long non-coding RNAs (769 upregulated, 534 downregulated) were identified, with the thresholds of false discovery rate < 0.05 and|log₂(fold change)| > 2. Significantly (p-adjusted < 0.05) overrepresented Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathways were analyzed, revealing upregulation of processes like pyruvate metabolic process, gluconeogenesis, ion transmembrane transport, neuropeptide signaling pathway, and animal organ development, with genes like SHH, GRK1, CHRM3, CAMK2A, and HSPB7 were upregulated, while translation and immune responses, with genes like RPS3, EEF1A1, TNF, BoLA-DRB3, and UBB were downregulated. Analysis of cis-mRNAs of DE-lncRNAs showed presence of both up- and down-regulated cis-mRNAs for both up- and down-regulated lncRNAs indicating existence of positive and negative regulation of mRNA expression by lncRNAs. Managemental nudges that decrease metabolic heat generation, like betaine and chromium supplementation, and increase heat dissipation, like microenvironment cooling, should be utilized. This study highlights the role of pyruvate metabolism and gluconeogenesis in coping up with heat stress and offers an improved understanding of the heat stress response of Sahiwal cattle along with the genes and pathways responsible for it.

The impact of declined natural greenery and increased built surfaces exacerbates heat stress in urban areas causing limited usage of outdoor spaces. Greenery strategies such as trees are capable of mitigating outdoor thermal stress gain because of their phytological properties. While urban greenery guidelines have suggested the ad-hoc procedure of tree planting-schemes based on aesthetic-value, soil-water preservation etc., understanding of their morphological character help in regulating extreme thermal condition. Hence, this study aims to investigate the most efficient planting pattern based on canopies densities and trees clusters for reducing the outdoor thermal stress from bio-meteorological perspective.It initiates with the measurement of the site's morphological and meteorological attributes in existing commercial market of Bhopal City which has a humid sub-tropical climate (Aw, Koppen climate categorization). Furthermore, it leads to the development of 4-different iterated clusters incorporating moderate to high-density canopies and their overlaps pattern to estimate reduction potential in outdoors using field surveys and validated simulation model. The reduction potential in terms of magnitude and duration of thermal stress is quantified across 3-thermal variables i.e., air temperature, mean radiant temperature and universal thermal climate index. Results indicate highly-dense canopies are more effective in reducing greater magnitude of thermal stress along longer duration. Also overlapped planting pattern within the same canopy density does not make significant difference in stress reduction as compared to the changing the densities. This study will help planners and landscape architects to adopt evidence-based planting-pattern strategies for improving outdoor microclimate.

Sky View Factor (SVF) is commonly used to describe the impact of urban geometry on the urban thermal environment. Shading effects from plants and buildings also exert a considerable influence. To investigate the influence of view factors on outdoor thermal comfort in residential areas, we employed the Physiological Equivalent Temperature (PET) and view factors (SVF, TVF, BVF) as indicators to determine outdoor thermal comfort and the quantity of shaded spaces. Thermal measurements collected from 13 points in Guangzhou, China, Our findings revealed that high TVF points exhibited more stable air temperature throughout the daytime, with average temperature differentials ranging 0.4-1.9 °C lower than other points. Air temperature demonstrated a positive correlation with SVF (R² = 0.53), while exhibiting a negative correlation with TVF (R² = 0.45). Additionally, shading provided by plants and buildings manifests heterogeneity. At similar SVF levels, points predominantly shaded by plants (TVF > BVF) showcased lower Mean Radiant Temperature (MRT) and PET compared to points shaded mainly by buildings (BVF > TVF). The maximum reduction in air temperature and PET reached 1.1 °C and 1.2 °C, respectively. BVF exerted greater influence earlier in the morning, as solar altitude angle rises, the average thermal parameters of sites with BVF > TVF escalated rapidly until eventually surpassing sites with TVF > BVF. Last, superior thermal conditions were only ensured under high shading conditions. When the effective shading ratio of plants and buildings diminished (SVF > 0.3), the microclimate of measurement points might be impacted by the long-wave radiation from the underlying surface.

Understanding phenological responses of tropical forest plant communities is crucial for identifying climate-induced changes in ecosystem dynamics. Monitoring phenology across diverse species in natural habitats provides cost-effective insights for conserving both species and forests. We studied tree phenology in a lowland evergreen dipterocarp forest in the Western Ghats, India. About 719 tree individuals representing 95 species were monitored for their vegetative and reproductive phenology from April 2021 to September 2023. Circular statistics detected seasonality in phenological events and Generalized Linear Mixed Modelling (GLMM) identified influence of climate variables on the phenological responses of the tree community. We also assessed how the activity and intensity of phenophases vary over the study period. Our results showed that leaf flushing and flowering peaked during the dry season, with mass flowering observed in two dominant dipterocarps. Fruit production peaked before the monsoon. We also observed diversity in vegetative and reproductive phenodynamics across species groups (forest strata, sexual system, and seed size). Leaf flushing was positively correlated with maximum relative humidity and negatively correlated with maximum temperature and the number of rainy days. Flowering had negative correlations with maximum relative humidity, rainfall days, and maximum temperature but showed a positive correlation with minimum temperature. Fruiting was positively correlated with maximum temperature and negatively correlated with rainy days. This detailed phenological information provides critical knowledge on resource availability and insights into how climate and seasonal changes affect plant growth cycles thereby aiding reforestation and biodiversity conservation strategies in vulnerable forest areas.