Search Results (2,727)

Identifying reliable geochemical signals that reflect crustal stress evolution remains a major challenge in earthquake monitoring. Spring fluids, due to their deep circulation and rapid response, provide an important window into fault-zone processes. This study presents three years (May 2022–March 2025) of hourly hydrogen gas (H₂) concentration monitoring in spring gases from the Muji Basin on the northern Pamir Plateau, integrated with meteorological and seismic data. H₂ concentrations exhibited a stable diurnal pattern, positively correlated with water and air temperatures and negatively correlated with atmospheric pressure. Short-term anomalies during seismically quiet periods may reflect a combination of temperature-dependent solubility effects and transient degassing caused by localized gas accumulation and sudden release under heterogeneous fault and aquifer conditions. During seismically active phases, sustained increases in H₂ concentrations were also recorded; however, such anomalies did not consistently precede earthquakes, instead reflecting broader phases of tectonic instability and episodic fault-zone degassing. These findings highlight the potential of long-term H₂ monitoring to improve our understanding of the coupling between crustal stress, fluid transport, and degassing processes in tectonically active regions. Full article

Glacier retreat due to climate change is accelerating worldwide, yet the phenomenon remains abstract for many people, especially those unfamiliar with mountain environments. The Urban Glaciology experiment, conducted during Milan’s internationally renowned “Fuorisalone” 2024 design event, aimed to bridge this perceptual gap by simulating real glacier melt processes in a busy urban square. Three large ice blocks with contrasting surface conditions (i.e., clean, dirty, and debris-covered) were exposed to springtime urban temperatures, mimicking conditions found on Alpine glaciers during summer. Over one week, the blocks produced a total of 748 L of meltwater, with dirty ice melting up to four times faster than debris-covered ice, consistent with established albedo effects. These results confirmed the thermal analogy between Milan’s spring conditions (+15 to +20 °C) and the ablation season on Alpine glaciers. Visitors observed the differential melting in real time, supported by visual indicators, explanatory panels, immersive virtual experiences, and direct interaction with researchers and students. Informal interviews indicated that more than 60% of participants reported a perceptual shift, recognizing for the first time that urban temperatures can replicate glacier melting conditions. By embedding a science-based installation in a major cultural tourism event, the experiment reached a diverse, non-traditional audience—including tourists, designers, and citizens—and encouraged reflection on the implications of glacier loss. The success of this initiative highlights the potential of replicating similar models in other cities to raise awareness of environmental change through culturally engaging experiences. Full article

Domestic water heaters traditionally use natural gas or electric resistance to heat stored water. A gas water heater relies on a non-renewable resource, while an electric water heater might rely on electricity generated by a non-renewable resource. This study analyzes the performance of an electric water heater featuring a novel heating element design based on a positive temperature coefficient (PTC) material powered directly by solar photovoltaic (PV) modules in a northern latitude installation. The project analyzes the operation of two different design temperatures of the PTC heating elements (50 °C, and 70 °C) when fed by three solar PV panels during the spring in the high-latitude location of Anchorage, Alaska (61.2° N). Our results show that both design temperatures of the PTC heating elements are able to achieve self-regulation at a sufficient and safe operating temperature for a domestic use case. Analysis of water heater performance directly connected to PV power showed that the PTC-equipped water heater had a limited period of heating when sufficient solar irradiance is available. Because of this, restrictive use of the water heater might be necessary during periods of non-daylight hours to preserve hot water in an insulated tank. However, this PV-to-PTC setup could be effectively used in industrial, commercial, and research settings. Full article

This study assesses the impact of climate change and glacier retreat on river runoff in the high-altitude Terek River Basin using the physically based ECOMAG hydrological model. Sensitivity experiments examined the influence of glaciation, precipitation, and air temperature on runoff variability. Results indicate that glacier retreat primarily affects streamflow in upper reaches during peak melt (July–October), while precipitation changes influence both annual runoff and peak flows (May–October). Rising temperatures shift snowmelt to earlier periods, increasing runoff in spring and autumn but reducing it in summer. The increase in autumn runoff is also due to the shift between solid and liquid precipitation, as warmer temperatures cause more precipitation to fall as rain, rather than snow. Scenario-based modeling incorporated projected glacier area changes (GloGEMflow-DD) and regional climate data (CORDEX) under RCP2.6 and RCP8.5 scenarios. Simulated runoff changes by the end of the 21st century (2070–2099) compared to the historical period (1977–2005) ranged from −2% to +5% under RCP2.6 and from −8% to +14% under RCP8.5. Analysis of runoff components (snowmelt, rainfall, and glacier melt) revealed that changes in river flow are largely determined by the elevation of snow and glacier accumulation zones and the rate of their degradation. The projected trends are consistent with current observations and emphasize the need for adaptive water resource management and risk mitigation strategies in glacier-fed catchments under climate change. Full article

Regional drought monitoring based on the Temperature Vegetation Drought Index (TVDI) holds significant potential in efforts to ensure food safety. However, its empirical determination of dry and wet edges introduces subjectivity and uncertainty, limiting its accuracy and applicability. An improved TVDI (iTVDI) was developed by optimizing boundary parameters using reinforcement learning, based on maximizing the correlation between the TVDI and the ERA5-Land soil moisture dataset. The findings are as follows: (1) The enclosed area and the absolute value of dry edge slope of iTVDI was 34.83–39.97% and 0.79–33.75% larger than TVDI, indicating that the iTVDI can be used to achieve better representation of drought conditions. (2) The iTVDI showed stronger correlations with ERA5 soil moisture (r: −0.416 to −0.174), with average |r| values 17.25% higher than TVDI; its correlations with Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), and the Vegetation Condition Index (VCI) were also 12.69–75.43% higher. (3) From 2005 to 2024, the spring drought in the Huaihe Basin intensified, with the annual iTVDI increasing by 0.008–0.011, primarily driven by rising temperature, potential evapotranspiration, and vapor pressure deficit. Overall, the iTVDI is proved to be more accurate and reliable for monitoring drought dynamics and driving factors. Full article

Achaea lienardi is a polyphagous moth occurring in sub-Saharan Africa. It is a fruit-sucking moth, causing secondary damage to fruit such as citrus and peaches, while the larval stage can cause significant tree defoliation, including in several indigenous trees, wattle, Eucalyptus, and castor oil plants, amongst others. In February and March of 2025, a massive outbreak of the caterpillars was observed in the Hluhluwe-iMfolozi Park in South Africa, feeding primarily on Tamboti trees (Spirostachys africana). Satellite imagery from the previous five years was examined, but no similar large defoliation events were observed during this period. Climate data for the last five years (September 2019–March 2025) were collated and examined to determine the conditions supporting the outbreak. Above average winter rainfall, early spring rains, sustained rains, and high humidity in January and February, with warm nighttime temperatures, likely acted in concert to create favourable conditions for the caterpillar outbreak. This outbreak coincided with historic outbreaks of the African armyworm (Spodoptera exempta) in the summer rainfall areas of South Africa where precipitation, temperature, solar radiation, and humidity were found to be critical factors affecting armyworm outbreaks. Further research is required to determine specific criteria to enable predictions of future outbreaks. Full article

River spring and flash floods are highly dependent on variations in meteorological conditions. In the Baltic States, substantial changes in air temperature and precipitation have been observed between the two most recent climate normal periods (1961–1990 and 1991–2020). Therefore, changes in the magnitude of spring and flash floods across different hydrological regions between these periods were analyzed to better understand shifting hydrological patterns. Daily flow data from 1961 to 2020 were obtained from 68 water gauging stations on 55 rivers. The Pettitt and Mann–Kendall tests, as well as Sen’s slope estimator, were applied to analyze the time series of flood maximum discharges. The most pronounced negative trends in spring and flash floods were observed in Lithuanian rivers, with the magnitude of these trends gradually weakening toward Latvia and Estonia. The maximum flood heights (h_MAX) generally declined during 1961–2020, particularly in Lithuania and western Latvia. Spring flood data showed the most significant decrease, particularly during 1991–2020, when h_MAX declined on average by 0.14 mm/year in Lithuania and 0.05 mm/year in Latvia. Flash floods exhibited smaller declines, also concentrated in 1991–2020. In the major rivers (Nemunas, Neris, and Daugava), peak discharges of both floods declined consistently throughout the study period. Full article

This study presents the results of a spatiotemporal analysis of indoor radon concentration dynamics at the Al-Farabi Kazakh National University (Almaty, Republic of Kazakhstan), located near the Almaty tectonic fault. The research is based on a 2.5-year monitoring campaign of radon levels using the RAMON-02A radiometer. The radon activity concentration ranged from 1.29 ± 0.19 to 149 ± 22 Bq/m³. The distribution of radon concentrations was found to follow a lognormal law, with a skewness coefficient of 1.55 and kurtosis of 4.7. The mean values were 28.7 ± 4.2 Bq/m³ (arithmetic mean) and 24.5 ± 3.6 Bq/m³ (geometric mean). Distinct seasonal and monthly variations were observed: the lowest concentrations were recorded during the summer months (August—20.8 ± 3.1 Bq/m³), while the highest were observed in spring and winter (May—34.0 ± 4.9 Bq/m³, December—34.2 ± 4.9 Bq/m³). The springtime increase in radon levels is attributed to thermobaric effects, limited ventilation, and precipitation, which contributes to soil sealing. Autocorrelation analysis revealed diurnal, seasonal, and annual fluctuations, as well as quasi-periodic variations of approximately 150 days, presumably linked to geophysical processes. Correlation analysis indicated a weak positive relationship between radon concentration and air temperature during winter and spring (≈0.2), and a pronounced negative correlation with atmospheric pressure in winter (−0.57). The influence of humidity was found to be minor and seasonally variable. Full article

Globally, biodiversity is declining, meaning that many endemic plants are under threat; therefore, it is essential to develop conservation strategies. Scutellaria indica var. coccinea has great potential as an ornamental ground cover plant, but it is a plant that requires ex situ conservation. This study was conducted in order to investigate the seed germination characteristics and classify the dormancy type of S. indica var. coccinea seeds, with the aim of developing mass propagation protocols for ex situ conservation and preservation of their genetic diversity. Fresh and mature seeds of S. indica var. coccinea are in a dormant state, which is released by low temperatures during winter, resulting in radicle and seedling emergence the following spring. At the time of dispersal, the seeds had fully developed embryos, and the seed coat was permeable. When the seeds were incubated under four different temperature regimes (4, 15/6, 20/10, or 25/15 °C), they showed a low germination percentage (≤20%), indicating that a substantial proportion of the seeds remained in a dormant state. In the cold stratification experiment (0, 4, 8, or 12 weeks at 4 °C), germination increased, and the time required for germination shortened as the duration of cold treatment lengthened. This suggests that low temperatures are the primary environmental signal that induces germination. In the gibberellic acid (GA₃) treatment (GA₃ 0, 10, 100, or 1000 mg·L⁻¹), relatively high concentrations (100 and 1000 mg·L⁻¹) were effective in promoting germination. The highest germination was obtained in GA₃ 1000 mg·L⁻¹ with 100.0%, which is about 7 times higher than the control (13.6%). Therefore, seeds of S. indica var. coccinea were classified as having non-deep physiological dormancy (PD). Additionally, because the minimum germinable temperature range of the seeds was extended to lower temperatures, the seeds were classified as having type 2 non-deep PD. Full article

This study investigates the impact of climate change on the Mudurnu Stream Basin in northwest Türkiye by analyzing climate parameters in the Mediterranean region. Historical data from EC-Earth2, HadGEM2-ES, and MPI-ESM-MR GCMs from the CMIP5 Euro-CORDEX archive were assessed, and future precipitation and temperature data were derived using five statistical bias correction methods for the selected EC-Earth2 model under RCP4.5 and RCP8.5 scenarios. The SWAT model was employed to simulate future runoff amounts for the Mudurnu Stream Basin. The findings reveal notable changes in precipitation and temperature. The annual and seasonal variations of total precipitation and average, maximum, and minimum temperatures for the RCP4.5 and RCP8.5 scenarios in the Sakarya and Mudurnu regions were analyzed and determined. The projections for future river flow indicate a significant increase in precipitation during the rainy seasons. The Mudurnu Stream mainstem will experience an increase in flow of between 70 and 140% under RCP4.5 and between 80 and 160% under RCP8.5. In the Dinsiz Stream tributary, a 32–55% increase is observed for the spring and summer months. In this context, the rainfall and runoff projections required for the estimation of potential drought and flood risks in the near and distant future were calculated. Full article

Climate change is expected to have significant effects on crop yield in the Canadian Prairies. The objective of this study was to investigate these possible effects on spring wheat, barley and canola production using the Decision Support System for Agrotechnology Transfer (DSSAT) modelling platform. We applied 21 climate change scenarios from high-resolution (0.22°) regional simulations to three modules, DSSAT-CERES-Wheat, DSSAT-CERES-Barley and CSM-CROPGRO-Canola, using a historical baseline period (1985–2014) and three future periods: near (2015–2040), middle (2041–2070), and far (2071–2100). These simulations are part of CMIP6 (Coupled Model Intercomparison Project Phase 6) and have been processed using statistical downscaling and bias correction by the NASA Earth Exchange 26 Global Daily Downscaled Projections project, referred to as NEX-GDDP-CMIP6. The calibration and validation results surpassed the thresholds for a high level of accuracy. Simulated yield changes indicate that climate change has a positive effect on spring wheat and barley yields with median model increases of 7% and 11.6% in the near future, and 5.5% and 9.2% in the middle future, respectively. However, in the far future, barley production shows a modest increase of 4.4%, while spring wheat yields decline significantly by 17%. Conversely, simulated canola yields demonstrate a substantial decrease over time, with reductions of 25.9%, 46.3%, and 62.8% from the near to the far future, respectively. Agroclimatic indices, such as Number of Frost-Free Days (NFFD), Heating Degree-Days (HDD), Length of Growing Season (GSL), Crop Heat Units (CHU), and Effective Growing Degree Days (EGDD), exhibit significant correlations with spring wheat. Conversely, precipitation indices, such as very wet days and annual 5- and 10-day maximum precipitation, have a stronger correlation with canola yield changes when compared with temperature indices. The results provide key guidance for policymakers to design adaptation strategies and sustain regional food security and economic resilience, particularly for canola production, which is at significant risk under projected climate change scenarios across the Canadian Prairies. Full article

Bee pollination is an indispensable part of agricultural production and a crucial factor in maintaining ecosystem balance and biodiversity. Understanding foraging behavior and pollination effects is essential for the management of bee pollination. Over a two-year experiment, we evaluated the foraging behavior and pollination effects of bumblebee Bombus terrestris and Chinese honeybee Apis cerana cerana on cherries in orchards. Results showed that all bees exhibited enhanced foraging activity as daytime temperatures rose in early spring. However, the daytime foraging activity of bumblebees differs from that of Chinese honeybees. The number of bumblebees leaving the hive exhibited two peak periods, whereas Chinese honeybees showed only one peak period. Bumblebees had longer working hours and greater pollen-carrying capacity than Chinese honeybees. Undoubtedly, cherries pollinated by bees had higher yields, as indicated by a greater fruit setting rate and yield. Thus, as effective pollinators, their pollination significantly boosts production and presents a viable option for widespread use in cherry cultivation. However, the risk of biological invasion by exotic bumblebees cannot be overlooked before extensive use. Full article

The Three-River Source Region (TRSR) of the Tibetan Plateau (TP) is a critical headwater area with complex alpine terrain and significant climate variability. Accurately simulating 2 m air temperature (T₂) in this region remains challenging for models such as the Weather Research and Forecasting (WRF) model. This study integrated remote sensing data into the WRF model to improve T₂ simulations over the TRSR. Two simulations were conducted for 2020: a control simulation with default static vegetation parameters (EXP_control) and a sensitivity simulation with realistic vegetation and associated surface albedo of 2020 from the Global Land Surface Satellite (GLASS) datasets (EXP_glass). Results showed that incorporating the GLASS-derived datasets significantly alleviated the cold bias in simulated T₂ during winter and spring, while maintaining comparable performance in summer and autumn. The EXP_glass run achieved better agreement with observations (R = 0.98, p < 0.01) and reduced root-mean-square error (RMSE) by 36.4% compared to EXP_control. Energy balance analysis indicated that the GLASS-derived datasets enhanced solar energy absorption and increased net radiation. Consequently, EXP_glass produced greater turbulent heat fluxes and warmer surface skin temperature (TSK) and T₂. This study underscores the importance of accurate land surface characterization and highlights the utility of remote sensing data for improving regional climate model performance in high-altitude regions. Full article

This study presents a comprehensive analysis of climate evolution in the Porto region (Northern Portugal) using 148 years (1863–2010) of continuous meteorological data from the Serra do Pilar weather station (WMO station 08546). The research employs both traditional linear statistical methods and advanced non-linear analysis techniques, including polynomial trend fitting and multidecadal oscillation analysis, to accurately characterize long-term climate patterns. Results reveal that linear trend analysis is misleading for this dataset, as both temperature and precipitation follow parabolic (U-shaped) distributions with minima around 1910–1970. The early period (1863–1900) exhibited higher values than the recent period, contradicting linear trend interpretations. Advanced analysis shows that the mean temperature follows a parabolic pattern (R² = 0.353) with the minimum around 1935, while precipitation exhibits similar behavior (R² = 0.053) with the minimum around 1936. Multidecadal oscillations are detected with dominant periods of 46.7, 15.6, and 10.0 years for temperature, and 35.0, 17.5, and 4.5 years for precipitation. Maximum temperatures show complex oscillatory behavior with a severe drop around 1890. Seasonal analysis reveals distinct patterns across all seasons: winter (+0.065 °C/decade) and autumn (+0.059 °C/decade) show warming trends in maximum temperatures, while spring (−0.080 °C/decade) and summer (−0.079 °C/decade) demonstrate cooling trends in minimum temperatures, with no significant trends in spring (+0.012 °C/decade) and summer (+0.003 °C/decade) maximum temperatures or winter (−0.021 °C/decade) and autumn (−0.035 °C/decade) minimum temperatures. The study identifies a significant change point in mean temperature around 1980, which occurs approximately one decade earlier than the global warming acceleration typically observed in the 1990s, suggesting regional Atlantic influences may precede global patterns. Extreme event analysis indicates stable frequencies of hot days (averaging 3.6 days/year above 25.0 °C) and heavy precipitation events (averaging 1.2 days/year above 234.6 mm) throughout the study period. These findings demonstrate that the Porto region’s climate is characterized by natural multidecadal variability rather than monotonic trends, with the climate system showing oscillatory behavior typical of Atlantic-influenced coastal regions. The results contribute to understanding regional climate variability and provide essential baseline data for climate change adaptation strategies in Northern Portugal. The results align with broader patterns of natural climate variability in the Iberian Peninsula while highlighting the importance of non-linear analysis for comprehensive climate assessment. Full article

Water quality in natural mineral springs is essential for sustainable use and conservation in the Amazon region. This study presents a hydrogeochemical characterization of 21 springs in the Peruvian Tropical Highlands, expanding on previous records of only six sources. The springs, which are thermal, saline, and sulfurous, are located between 384 and 3147 m a.s.l., mainly in mountainous areas with structural slopes and permeable sedimentary formations, such as the Pulluicana Group (composed mainly of sandstones and shales) and the Sarayaquillo Formation (characterized by reddish sandstones and siltstones). Physicochemical analysis showed temperatures ranging from 15.1 to 38.2 °C, pH from 5.20 to 8.72, conductivity between 0.05 and 253 mS/cm, and total dissolved solids from 0.02 to 162.50 g/L. High levels of arsenic and aluminum, likely originating from the natural weathering of rocks rich in these elements, exceeded national limits. Microbiological analysis detected fecal coliforms and Escherichia coli, indicating potential health risks. The results highlight the importance of regular monitoring and proper management to ensure safe use and explore its therapeutic and biotechnological applications, such as microbial bioremediation or development of extremophile-based enzymes. Full article