International Journal of Biometeorology最新文献

Frequent drought events greatly decrease the gross primary productivity (GPP) and disturb the carbon dynamics of ecologically fragile grassland ecosystems. While GPP is controlled both by canopy structure-related fraction of absorbed photosynthetically active radiation and leaf physiology-related light use efficiency, the underlying mechanisms of drought-induced decline in photosynthetic capacity remain unclear in grassland ecosystems. Here, we used ground-observed maximum GPP based on flux tower (GPP_peak) and satellite-retrieved maximum solar-induced chlorophyll fluorescence (SIF_peak) within each year as the proxy of photosynthetic capacity of alpine grasslands (AG) and temperate grasslands (TG) in China. We first decomposed GPP_peak and SIF_peak into radiation, structure, and physiological components, and compared their relative changes in drought years versus normal years at both local and regional scales. Results showed that declines in GPP_peak and SIF_peak under drought were more pronounced in TG due to its more arid climates. In TG, canopy structure was the main component driving photosynthesis loss because of the smaller proportion of carbon allocation to leaves under drought. However, in AG, the decline in leaf physiology was the primary component. Structural equation modeling revealed that changes in structure and physiological components dominated the spatial variance of SIF_peak response to drought in TG and AG, respectively. The alteration in environmental factors under drought could explain most of the spatial variance of changes in canopy structure and leaf physiology. These findings enhance understanding of the mechanisms behind grassland photosynthetic response to drought, providing insights critical for predicting ecosystem carbon balance under climate change.

In recent decades, flash drought events have frequently occurred in the humid regions of southern China. Due to the sudden onset and rapid intensification of these droughts, they often cause severe damage to vegetation photosynthesis. However, our understanding of the spatiotemporal evolution characteristics of flash droughts across different vegetation types, as well as the response regularity of photosynthesis to flash droughts, especially early responses, remains limited. This study analyzes the spatiotemporal evolution characteristics of flash droughts for different vegetation types in the Middle and Lower Reaches of the Yangtze River Basin from 2000 to 2023. It uses solar-induced chlorophyll fluorescence (SIF) and fluorescence yield ([Formula: see text]) to explore the response regularity of vegetation photosynthesis to flash droughts, with a systematic analysis of the 2013 flash drought event. The results show that, over the past 24 years, the frequency of flash droughts for different vegetation types in the Middle and Lower Reaches of the Yangtze River Basin has decreased, but the total duration has increased, with forests experiencing the highest frequency of flash droughts, while cropland experiences the least. Cropland photosynthesis is the most sensitive to flash drought, showing an early response 8-16 days after the onset and reaching a negative anomaly between 24 and 32 days. Forests mainly show an early response between 16 and 24 days and a negative anomaly response between 32 and 40 days. During the 2013 flash drought, cropland showed an early response on the 10th day after the onset and a negative anomaly on the 26th day, while forest responses were later, with early responses on the 20th day and negative anomalies on the 36th day. These results align with long-term statistical data. This study contributes to a deeper understanding of vegetation photosynthesis response regularity to flash droughts and provides insights for developing effective flash drought management strategies.

This study aimed to examine the impact of climatic conditions on feed intake, body weight, and rectal temperature in horses residing in the hot Summer Mediterranean climate zone. Eight gelding Italian Saddle horses, with an average body weight of 427.78 ± 54.55 kg and aged between 10 and 13 years, participated in the research. All horses were individually housed in a paddock (800 m²/horse), and fed ad libitum. Food intake, body weight, and rectal temperature were recorded every 10 days at four 30-day collection periods in the year: January, April, July, and October. The formula adapted from Thom (Weatherwise, 12,57-61, 1959) was used to calculate the temperature-humidity index (THI). The total and daily average feeding intake was computed based on the recorded temperature and humidity for each season. No statistical difference among seasons and data points in the total and daily average feeding ingestion, body weight and rectal temperature were recorded. This study demonstrates that horses kept in paddocks and provided ad libitum access to uniformly high-quality hay exhibit consistent feed intake, body weight, and rectal temperature across different seasons, with minimal inter- and intra-subject variability in the hot Mediterranean summer climate.

Climate-responsive urban design requires a thorough understanding of how street canyon morphology affects the thermal environment, especially for the severe cold regions in Northern China. Individual geometric parameters often overlook other geometric characteristics of real street canyons, making it impossible to establish precise correlations between morphological parameters and thermal environments. This study investigates the influence of six key geometric parameters on thermal conditions in Hohhot, China. Mobile measurements revealed a significant quadratic relationship between the asymmetrical aspect ratio and mean air temperature at 12:00 (R² = 0.91654). We also found that the aspect ratio, the complementary index closing ratio, and the smoothness rate were negatively correlated with mean air temperature at various times, while height variation positively influenced air temperature (R² = 0.67946). Furthermore, the building coverage ratio in adjacent areas significantly impacted mean radiant intensity (R² = 0.700 and 0.679 at 11:00 and 12:00, respectively, p < 0.05). Multiple regression analyses underscored the collective impact of these parameters on thermal conditions. These findings provide valuable insights for optimizing street canyon design to improve thermal comfort, thereby contributing to more effective climate-responsive urban planning.

Exposure to low and high ambient daily temperature has been associated with cardiovascular diseases. However, the hourly association, which may enable a more precise healthcare response, has rarely been explored. This study conducted a time-stratified case-crossover analysis of emergency patients with acute chest pain at the Chest Pain Center (CPC) in Foshan, China from 2018 to 2023. We employed a conditional logistic regression model coupled with a distributed lag non-linear model (DLNM) to evaluate the hourly exposure-lag-response associations with adjustment for potential confounding factors. A total of 17,634 emergency patients with acute chest pain were recorded in this study. We found that cold exposure was significantly associated with the risk of cardiac chest pain (CCP) onset within 0-144 h prior to onset. The odds ratios (ORs) of CCP onset were 1.793 (95% CI: 1.345, 2.390) for cold air temperature (14.7 ℃) and 1.772 (95% CI: 1.353, 2.320) for cold apparent temperature (13.9 ℃), respectively. Non-optimal temperatures exposure, particularly heat, was associated with an elevated risk of non-cardiac chest pain (NCCP) onset, with the highest cumulative risk occurring at a lag of 72 h, and the corresponding ORs were 2.368 (95% CI: 1.374, 4.082) for air temperature and 2.107 (95% CI: 1.334, 3.327) for apparent temperature. This study reveals the positive association between hourly temperature and the onset of the acute chest pain. These findings highlight the importance of positive measures, such as enhancing timely temperature alert systems and optimizing medical resource allocation.

The changing climate and rising occurrence of heat events may impact incidence and severity of occupational traumatic injuries. The objective of this research is to characterize the association between daily hospital presentations for work-related traumatic injuries and temperature in Illinois, USA. The Illinois outpatient and inpatient hospital databases were used to identify work-related traumatic injuries treated in Illinois hospitals during the summer months from May to September between 2017 to 2023. National weather service data was used to assess temperature metrics in Illinois. We used generalized linear mixed models to examine the association between daily hospital presentations for work-related traumatic injuries and two temperature related events: (1) extreme heat days and (2) days with increasing temperatures above 76°F(24.4 °C) as workers begin to acclimate to increasing ambient temperatures. Models were stratified by worker demographics, cause and nature of injury. Over the study period there were 95,038 hospital presentations for work-related traumatic injuries.. We observed a significant daily increase in traumatic injuries of 1.52% (95%CI: 0.19%, 2.87%, p < 0.05) during days with sequentially increasing temperatures above 76°F(24.4 °C). Workers aged 16-19 years, Hispanic workers, and workers presenting with open wound injuries and injuries caused by contact with or against objects also showed significant increase in injuries. An increase on extreme heat days in the adjusted models was seen in traumatic brain injuries (22.74%, 95%CI: 2.57, 46.86%, p < 0.05). Results indicate differences in susceptibility to traumatic injuries by demographic characteristics and mechanisms of injury during both periods of acclimatization to heat and extreme heat days.

Current predictions of climate change impacts rely on conservative assumptions about a lack of adaptation, projecting significantly increased heatwave mortality. However, long-term studies have shown a decline in actual heatwave deaths, raising questions about the underlying mechanisms. We combined Eurostat weekly mortality data (baseline extracted via Seasonal-Trend decomposition by Loess and smoothed through Principal Component Analysis dimension reduction and reconstruction) with economic indicators, Copernicus temperature data since 1950, and ENTSO-E electricity demand data. Panel regression analyzed mortality patterns during weeks with daily temperatures exceeding 22 °C for 2000-2022. During the analyzed period, Europe outpaced climate change, with the capacity to tolerate an additional 1 °C rise every 17.9 years [95% CI 15.3-22.7]. Extending the temperature indicators beyond the prior 3 years did not enhance predictive accuracy, suggesting swift adaptations and historical climate lacked any predictive value. Additionally, increasing economic output, likely driven by infrastructural improvements, especially greater affordability of air conditioning, enabled tolerating each additional 1 °C due to a per capita GDP increase of 19.7 thousand euros [95% CI 14.6-30.3]. Consistently, the increase in cooling energy demand was the strongest in eastern Europe. The findings shed light on the mechanisms driving the observed reduction in heatwave mortality despite the warming climate trend, offering a more plausible basis for extrapolation than assuming a lack of adaptation. The model emphasizes the role of long term economic growth and addressing energy poverty.

The aim of the presented study was to characterize the territory of Poland in terms of the frequency of occurrence of specific values of IAPC (interdiurnal atmospheric pressure changes) and to determine synoptic situations accompanying their particularly high values. The study is based on the daily mean atmospheric pressure data from the years 1966-2022 taking from 48 meteorological stations in Poland. In the presented paper four IAPC categories were used: A < 4.0 hPa (weak sense of change), B 4.1-8.0 (moderate sense of change), C 8.1-12.0 (strong sense of change), and D > 12.1 (very strong sense of change). Taking into account the negative impact on human health and well-being of the IAPC value, and especially its declines (conductive to the increase of suicides, heart and kidney diseases, asthma), the most unfavorable in this respect in Poland is the northern part of the country. The greatest frequency of synoptic situations causing the above-mentioned influence occurs in the cold half of the year, especially in winter. In turn the beneficial impact of the increase in IAPC on human health and well-being in terms of blood oxygenation and reduced suicide mortality caused by IAPC also occurs in the northern Poland. The frequency of synoptic situations felt in this respect is also highest in the cold half of the year.