Winter Conditions Research Articles

Multi-objective optimization of building envelope of rural housing in the severely cold region of China based on energy consumption, thermal comfort and cost-effectiveness

The performance of rural residential buildings has a great energy-saving potential due to the great spontaneity and ignorance of the rural residential construction. To solve this problem, this paper provides a multi-objective optimization model based on Chebyshev inequality. The model takes energy consumption, indoor thermal comfort, project cost as optimization objectives and considers operating conditions in winter and summer. This study taking a rural residential house as an example and analysed the influence of its envelope parameters on building performance using EnergyPlus. The parameters of the building envelope were optimized, which verified the superiority of the method. Optimization results showed that the heating energy consumption was reduced by 29%, and the air conditioning energy consumption was reduced by 6%. This study analysed the relationship between the building energy consumption, indoor thermal comfort and the cost by multi-objective optimization method, to provide a new research idea for rural residential research. Optimal design solutions were generated under various weighting coefficients. The model aimed to meet the climatic and economic conditions of northern China and similar regions. Therefore, based on these optimization results, decision-makers can choose optimal design and construction solutions according to their own will.

Simulated winter climate change reveals greater cold than warm temperature tolerance in Chrysolina polita (Coleoptera: Chrysomelidae).

Climate change is expected to lead to rising winter temperatures in temperate zones, coinciding with a decrease in winter snow cover. Insects adapted to winter conditions in the temperate zone might be exposed to changing winter conditions and higher temperature fluctuations, which can affect diapause and mortality. We studied the effects of climate change on Chrysolina polita, a temperate zone species overwintering as an adult in the shallow surface of the soil. We tested the effects of increased and fluctuating temperature on the mortality and body composition of the beetles in a laboratory environment, as well as the effects of snow cover removal on the mortality and body mass in field conditions. We found that in the laboratory study, a 2 °C increase in mean temperature increased mortality and resulted in increased lipid consumption, whereas temperature fluctuation caused desiccation of the beetles but did not affect mortality compared to the control condition. In the field study, the snow removal caused the mean soil temperature to decrease by 3 °C and fluctuate (ranging from -26.4 to 2.5 °C compared to a range of -1.7 to 0.5 °C in the control), yet these differences did not affect beetle mortality or body mass. We conclude that C. polita exhibits greater resistance to cold temperatures than to higher temperatures during diapause. Therefore, the rising temperatures associated with climate change can pose challenges for overwintering.

Vegetation Effects on Air Pollution: A Comprehensive Assessment for Two Italian Cities

The role of urban vegetation in urban air quality is usually assessed by considering only the pollutant removal capacity of the plants. This study aims to show, for the first time, the effects of vegetation on air pollutant concentrations through its effects on meteorology, separately from its biogenic emissions. It also investigates how air quality changes when only biogenic emissions are altered by using plants with different emission factors, as well as the potential effects of introducing new vegetation into urban areas. These assessments were conducted using atmospheric modelling systems currently employed for air quality forecasting and planning, configured specifically for the cities of Bologna and Milan. Simulations were performed for two representative months, July and January, to capture summer and winter conditions, respectively. The variability in air concentrations of ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM10) within the municipal boundaries was assessed monthly. When evaluating the impact of future vegetation, changes in temperature, wind speed, and relative humidity were also considered. The results indicate that vegetation influences air quality more significantly through changes in meteorological conditions than through biogenic emissions. Changes in biogenic emissions result in similar behaviours in O3 and PM10 concentrations, with the latter being affected by the changes in the concentrations of secondary biogenic aerosols formed in the atmosphere. Changes in NO2 concentrations are controlled by the changes in O3 concentrations, increasing where O3 concentrations decrease, and vice versa, as expected in highly polluted areas. Meteorologically induced vegetation effects also play a predominant role in depositions, accounting for most of the changes; however, the concentrations remain high despite increased deposition rates. Therefore, understanding only the removal characteristics of vegetation is insufficient to quantify its effects on urban air pollution.

Reduced scale experiment and numerical simulation study on different airflow organization modes in large ship painting workshop

Mechanical ventilation is a key means to improve indoor air quality in shipbuilding industry. Appropriate airflow organization will have a perceptible impact on environmental safety, personnel health, and energy conservation. Many ship painting workshops use fully mixed ventilation, making it difficult to meet indoor pollutant standards and save energy. Therefore, it is necessary to optimal design the airflow organization in the ship painting workshop reasonably. This article introduces three new air supply strategies for ship painting workshops, namely piston flow air supply, attached jet air supply, and side air supply, and compares them with the existing mixed air supply. Three operating scenarios have been established, including isothermal conditions in spring and autumn, cooling condition in summer, and heating condition in winter. The airflow and pollutant distribution of each airflow organization are compared through scale model experiments and numerical simulations. Finally, the most suitable strategy for the workshop in each season is selected and promoted for engineering applications.

Phytoplankton community composition links to environmental drivers across a fjord to shelf gradient on the central coast of British Columbia

Rapid environmental change is altering coastal phytoplankton dynamics and, thereby the productivity of coastal marine food webs. Unfortunately, a paucity of phytoplankton community data hinders the prediction of future conditions in ecologically productive regions such as the coastal northeast Pacific. To help fill this gap, this study characterized phytoplankton communities from 2018 to 2020 across a fjord, channel and shelf station transect on the central coast of British Columbia, Canada. Monthly samples were collected for microscopy-based taxonomy and pigment-based phytoplankton composition (i.e. CHEMTAX and size-fractionated chlorophyll). Correlation analysis was used to investigate drivers of phytoplankton biomass and hierarchical clustering and redundancy analysis highlighted drivers of compositional trends. Spring blooms formed the peak of annual biomass at each station and earlier blooms at the fjord station suggested a sheltering effect from winter wind conditions. Later spring blooms at the channel station coincided with seasonal wind reductions and increased sunlight. Of the six derived compositional clusters, three represented flagellate dominated conditions at all stations: two represented low biomass winter conditions and the third, moderate biomass spring and autumn blooms occurring under nutrient replete conditions. The remaining three clusters were diatom-dominated and spanned much of the growing season. The first diatom cluster represented Skeletonema marinoi dominated samples, many from 2020, observed under moderate nutrient and high stratification and freshwater discharge conditions. The second represented high diatom richness spring bloom conditions at all stations that were associated with nutrient depletion. Finally, the third included 2018 and 2019 summer shelf samples showing harmful Rhizosolenia setigera and Pseudo-nitzschia seriata blooms under high surface water salinity and temperature. These results highlight high spatial-temporal variability and sensitivity of coastal northeast Pacific phytoplankton communities to altered freshwater, temperature and wind dynamics with potential for profound ecosystem level implications.

Removal efficiencies for 52 pesticides and pharmaceuticals from wastewater effluent by coupling solar heterogeneous photo-oxidation with TiO2 and infiltration in saturated soil column

Water resource management has become a hot button issue in recent decades. Countries facing water shortages as a result to climate change must adapt their water supply. The reuse of wastewater treatment plant effluents is becoming increasingly common around the world. However, the effluent quality must be improved before its reutilization to avoid contamination of the receiving environment. Pharmaceuticals and pesticides are particularly monitored because of their ubiquitous behaviours and limited removal by conventional wastewater treatment plants. The aim of this study was to combine heterogeneous photo-oxidation with TiO2 and soil infiltration to increase the elimination of contaminants of emerging concern (CECs). These advanced treatments were applied on an effluent coming from a WWTP equipped with a Ultrafor membrane bioreactor (sludge ages: 8–30 days, biomass concentration: 8-12 g.L−1, hydraulic retention: 6.7-8 h). The concentration of CECs was determined to evaluate the efficiency of coupling treatments. Photo-oxidation alone showed an impressive 98 % removal under spring conditions, while 66 % removal was observed under winter conditions. The differences observed for photo-oxidation were related to UV flux density, lower in winter than in spring (4.4 kJ.L−1 vs 6.6 kJ.L−1) and initial concentrations of the effluent higher in winter (50 μg.L−1 vs 26 μg.L−1). For both experiments, additional soil infiltration increased the global concentration of CECs removal to at least 89 % with equal removal contributions observed for some compounds. From the 52 CECs quantified in the WWTP effluent, at least 30 were totally removed by the advanced treatments while 4 compounds showed recalcitrant behaviours with global removal <60 %.

Immature survival and female longevity of Aedes aegypti under natural winter conditions in the temperate region of Argentina

Immature survival and female longevity of Aedes aegypti under natural winter conditions in the temperate region of Argentina

Environmental and economic assessment of urban wastewater reclamation from ultrafiltration membrane-based tertiary treatment: Effect of seasonal dynamic

This study aimed to assess the environmental and economic performance of an ultrafiltration (UF) tertiary treatment of effluent from an urban wastewater treatment facility. Data from a UF demonstration plant composed of commercially available equipment, including industrial hollow-fiber membranes was used to project a full-scale facility. The results from the demonstration plant recommended different ranges of transmembrane fluxes and sparging air demands under summer and winter conditions to prevent excessive fouling. The energy balance of the full-scale facility would be 0.308 ± 0.112 kWh·m−3 in summer and 0.140 ± 0.040 kWh·m−3 in winter, with blowers' being the main consumers (86–93 %). CAPEX accounted for €0.030 ± 0.002·m−3 in summer and €0.027 ± 0.002·m−3 in winter and membrane acquisition represented 66–69 % of the investment cost. Energy expenditure was the major OPEX cost (66–79 %), with a total operating cost of €0.077 ± 0.023·m−3 and €0.042 ± 0.008·m−3 in summer and winter, respectively. The final average value obtained for the TAC was €0.107 m−3 in summer and €0.068 m−3 in winter. The environmental assessment confirmed optimizing energy consumption and membrane requirements as the main factors influencing environmental sustainability. Specifically, summer and winter emissions of 0.079–0.175 and 0.043–0.079 kgCO2eq·m−3 (Global warming potential); 8.1 · 10−4–1.7 · 10−3 and 4.8 · 10−3–8.1 · 10−3 m3·m−3 (water consumption); 0.019–0.041 and 0.010–0.019 kg oileq·m−3 (fossil fuel scarcity); and 1.4 · 10−4–2.9 · 10−4 and 7.7 · 10−4–1.4 · 10−4 kg Cueq·m−3 (mineral resource scarcity) were calculated, respectively. The obtained permeate quality complied with the most stringent Spanish and EU regulations.

Field Evaluation of Raspberry Cultivars in North Dakota

In North Dakota, USA, harsh winter conditions cause considerable winter injury to many floricane fruiting raspberries. Short growing seasons in North Dakota inevitably result in an incomplete fruit harvest of primocane fruiting raspberries. In this study, the winter hardiness of six floricane fruiting raspberry and five primocane fruiting raspberry cultivars had been evaluated for multiple years since 2016. Results showed that five floricane cultivars (Prelude, Boyne, Killarney, Nova, and Encore) showed less than 20% buds damaged, whereas cultivar Amethyst had 20% to 50% buds damaged in the winter. Severe bud damage was observed in five primocane fruiting cultivars (Polana, Autumn Bliss, BP-1, Heritage, and Joan J) in which Polana had the least winter bud damage with significant variations among years, followed by Heritage, Joan J, and Autumn Bliss, and BP-1. No winter damage was observed of the root system. In addition, the fruit quality, cane height, and yield of the six floricane fruiting cultivars were evaluated. Results showed that ‘Killarney’ fruit was the largest (2.50 g per berry) followed by ‘Nova’ (2.35), ‘Encore’ (2.24), ‘Amethyst’ (2.12), ‘Prelude’ (1.94), and ‘Boyne’ (1.84). No significant differences in total soluble solid (TSS) among cultivars were observed except that the TSS of Prelude was significantly lower than the other five cultivars. The cane height of ‘Killarney’ was the shortest (75 cm), whereas ‘Amethyst’ grew the longest canes (129 cm). Prelude is the earliest ripening floricane cultivar (late June) with a short harvest duration (20 to 25 days). The fruit harvest of ‘Killarney’, ‘Boyne’, and ‘Nova’ started 3 to 5 days after ‘Prelude’ with a longer harvest duration (25 to 30 days). ‘Encore’ and ‘Amethyst’ were harvested from mid-late July to early-mid August. Yield estimation indicated that ‘Killarney’ and ‘Nova’ produced more berries than other cultivars.

Distinct Bacterial Communities Within the Nonrhizosphere, Rhizosphere, and Endosphere of Ammodendron bifolium Under Winter Condition in the Takeermohuer Desert

Due to human activities and severe climatic conditions, the population of Ammodendron bifolium, an excellent sand-fixing plant, has gradually decreased in the Takeermohuer Desert. The plant-associated bacteria community can enhance its survival in harsh environments. However, the understanding of A. bifolium-associated bacterial community is still unclear during the harsh winter. We investigated the bacterial community structure from the A. bifolium rhizosphere and nonrhizosphere at different depths (i.e., 0–40 cm, 40–80 cm, 80–120 cm) and from endosphere (i.e., root endosphere and stem endosphere) in winter. At the same time, we analyzed the impact of different compartments and soil factors on the bacterial community structure. Studies have shown that the A. bifolium rhizosphere exhibits higher levels of SOM (soil organic matter), SOC (soil organic carbon), SAN (soil alkaline nitrogen), and SAK (soil available potassium) compared with the nonrhizosphere. The dominant bacterial phyla were Proteobacteria (19.6%), Cyanobacteria (15.9%), Actinobacteria (13.6%), Acidobacteria (9.0%), and Planctomycetota (5.7%) in the desert. Proteobacteria (24.0–30.2%) had the highest relative abundance in rhizosphere, Actinobacteria (18.3–22.6%) had the highest relative abundance in nonrhizosphere, and Cyanobacteria had the highest relative abundance in endosphere. At the genus level, the relative abundance of Pseudomonas (1.2%) in the root endosphere was the highest and the other genera were mostly unclassified. The Chao1 and PD_whole_tree indices showed that the diversity of the bacterial communities decreased from nonrhizosphere, rhizosphere, root endosphere to stem endosphere. Co-occurrence network analyses identified Proteobacteria and Actinobacteria as key species across the three compartments. Additionally, unique keystone species like Cyanobacteria, Verrucomicrobiota, and Desulfobacterota were found only in the endosphere. The bacterial community in the rhizosphere was influenced by factors such as EC (electrical conductivity), STC (soil total carbon), SOM, SOC, STN (soil total nitrogen), SAN, STP (soil total phosphorus), and SAK, while that of the nonrhizosphere was mainly influenced by pH, C/N (STC/STN), SAP, and distance. The study highlighted differences in bacterial community composition, diversity, and influencing factors across the three compartments, which can provide a better understanding of the association/interactions between A. bifolium and bacterial communities and lay a foundation for revealing its adaptability in winter.

The atmospheric oxidizing capacity in China – Part 2: Sensitivity to emissions of primary pollutants

Abstract. Despite substantial reductions in anthropogenic emissions, ozone (O3) pollution remains a severe environmental problem in urban China. These reductions affect ozone formation by altering levels of O3 precursors, intermediates, and the oxidation capacity of the atmosphere. However, the underlying mechanisms driving O3 changes are still not fully understood. Here, we employ a regional chemical transport model to quantify ozone changes due to a specified emission reduction (50 %) for winter and summer conditions in 2018. Our results indicate that reductions in nitrogen oxide (NOx) emissions increase surface O3 concentrations by 15 %–33 % on average across China in winter and by up to 17 % in volatile organic compound (VOC)-limited areas during summer. These ozone increases are associated with a reduced NOx titration effect and higher levels of OH radicals. Reducing NOx emissions significantly decreases the concentration of particulate nitrate, which enhances ozone formation through increased HO2 radical levels due to reduced aerosol uptake and diminished aerosol extinction. Additionally, an enhanced atmospheric oxidative capacity, driven by larger contributions from the photolysis of oxidized VOCs (OVOCs) and OH-related reactions, also favors urban ozone formation. With additional reductions in anthropogenic VOC emissions, increases in summertime ozone (VOC-limited areas) can be offset by reduced production of radicals from VOC oxidations. To effectively mitigate ozone pollution, a simultaneous reduction in the emission of NOx and specific VOC species should be applied, especially regarding alkenes, aromatics, and unsaturated OVOCs, including methanol and ethanol.

Simulation of wetland vegetation succession based on coupled Gaussian and population dynamics models: A case study of Poyang Lake wetlands

Wetland vegetation is the most crucial primary producer in wetland ecosystems and serves as an indicator of ecosystem health. After 2003, significant changes occurred in the “river-lake relationship” between Poyang Lake and the Yangtze River, with intensified dry conditions in autumn and winter leading to a shortened inundation period for sandbanks and significant changes in the community structure and spatial distribution of wetland vegetation. By coupling a Gaussian model with a population dynamics model, this study simulated the response of wetland vegetation to inundation duration under different hydrological year types, revealing the relationship between vegetation distribution and inundation duration. Key parameters, such as growth and mortality rates, were identified, and the vegetation succession and spatial distribution of Poyang Lake wetlands were simulated for five representative years: a wet year (2010), a normal year (2001), a dry year (2006), an extreme wet year (1998), and an extreme dry year (2022). The results showed that the response of wetland vegetation to inundation duration followed a Gaussian curve, with each species exhibiting an optimal range of inundation durations. Mortality rates increased when the duration fell outside this range. In 2010, the total area of wetland vegetation was similar to that in a normal year, but the proportions of different plant species varied significantly. Compared to 2001, the areas of Phalaris arundinacea and Polygonum criopolitanum increased by 50.92 % and 24.86 %, respectively, while the areas of Phragmites australis and Triarrhena lutarioriparia decreased by 71.66 % and 83.49 %. In 1998, the total vegetation area shrank considerably, with a 54.74 % reduction compared to 2001 and a 64.32 % reduction compared to 2006. In contrast, the total wetland vegetation area reached its maximum in the extreme dry year of 2022, increasing by 41.35 % compared to 2001. Among dominant species, Carex spp., Cynodon dactylon, and Phragmites australis expanded significantly in dry years, while Phalaris arundinacea and Polygonum criopolitanum were better adapted to flood conditions.

CHIMBO Air Quality Modeling System: Verification and Processes Analysis

This study presents an evaluation of the CHIMBO modeling chain applied to the Italian domain, specifically focusing on the Po Valley subdomain over the one-year period of 2019. The comparison between simulated and observed data indicates that the performance of the CHIMBO model aligns well with existing literature on other state-of-the-art models. The results demonstrate that the CHIMBO chain is particularly effective for regional-scale quantitative assessments of pollutant distribution, comparable to that of CAMS ensemble models. The analysis of key chemical species in particulate matter reveals that the CHIMBO model accurately represents the average concentrations of organic and elemental carbon, as well as secondary inorganic compounds (sulfate, nitrate, and ammonium), particularly at background monitoring stations in the flat terrain of the Po Valley, with the exception of Aosta, a city located at about 500 m asl. However, seasonal discrepancies were identified, especially during winter months, when significant underestimations were observed for several species, including elemental and organic carbon, predominantly at background sites. These underestimations are likely attributed to various factors: (i) inadequate estimations of primary emissions, particularly from domestic heating; (ii) the limited effectiveness of secondary formation processes under winter conditions characterized by low photochemical activity and high humidity; and (iii) excessive dilution of pollutants during calm wind conditions due to overestimation of wind intensity. In conclusion, while the CHIMBO modeling chain serves as a robust tool for mesoscale atmospheric composition investigations, limitations persist related to emissions inventories and meteorological parameters, which remain critical drivers of atmospheric processes.

The Great Lakes Winter Grab: Limnological data from a multi‐institutional winter sampling campaign on the Laurentian Great Lakes

AbstractInterest in winter limnology is growing rapidly, but progress is hindered by a shortage of standardized multivariate datasets on winter conditions. Addressing the winter data gap will enhance our understanding of winter ecosystem function and of lake response to environmental change. Here, we describe a dataset generated by a multi‐institutional winter sampling campaign across all five Laurentian Great Lakes and some of their connecting waters (the Great Lakes Winter Grab). The objective of Winter Grab was to characterize mid‐winter limnological conditions in the Great Lakes using standard sample collection and analysis methods. Nineteen research groups sampled 49 locations varying widely in depth and trophic status, collecting a range of limnological data. This dataset includes physical, chemical, and biological measurements. These data can be used to examine diverse aspects of Great Lakes ecosystems or integrated with winter observations from other lakes to improve understanding of winter limnology across different aquatic systems.

Boosting Winter Green Travel: Prioritizing Built Environment Enhancements for Shared Bike Users Accessing Public Transit in the First/Last Mile Using Machine Learning and Grounded Theory

Shared bikes are widely used in Chinese cities as a green and healthy solution to address the First/Last Mile issue in public transit access. However, usage declines in cold regions during winter due to harsh weather conditions. While climate factors cannot be changed, enhancing the built environment can promote green travel even in winter. This study uses data from Shenyang, China, to investigate how built environment attributes impact the travel satisfaction of shared bike users who utilize bikes as a First/Last Mile solution to access public transit in winter cities. By employing machine learning algorithms combined with Asymmetric Impact-Performance Analysis (AIPA) and grounded theory, we systematically identify the key attributes and rank them based on their asymmetric impact and urgency of improvement. The analysis revealed 19 key attributes, 17 of which are related to the built environment, underscoring its profound influence on travel satisfaction. Notably, factors such as the profile design of cycling paths and safety facilities along routes were identified as high priorities for improvement due to their significant potential to enhance satisfaction. Meanwhile, features like barrier-free access along paths and street greenery offer substantial opportunities for improvement with more modest efforts. Our research provides critical insights into the nuanced relationship between built environment features and travel satisfaction for First/Last Mile shared bike users. By highlighting priority improvements, we offer urban planners and policymakers a framework for creating livable, sustainable environments that support green travel even in harsh winter conditions.

Impact of winter conditions on wind erosion susceptibility of clay soils

Impact of winter conditions on wind erosion susceptibility of clay soils

Implications of temperature-dependent development and survival of Hemipteroseius adleri Costa, 1968 on its distribution in central Europe

Otopheidomenidae include 30 species of parasites of insects. These mites occur in areas with warm and hot climates. The only exception is Hemipteroseius adleri, the distribution of which reaches the central European region, which is characterised by a moderate climate with below-zero temperatures in winter. In Europe, H. adleri only parasitises the red firebug (Pyrrhocoris apterus). Field observations indicate that only fertilised females of H. adleri survive winter conditions. The aim of the study therefore was to evaluate the impact of air temperature on the development and survival of H. adleri. A research model was established involving mites parasitising red firebugs in laboratory conditions at 15, 20, 25 and 30 °C. After oviposition, no egg development was possible at 15 °C. Egg development began at 20 °C, however the egg-to-adult period lasted for 13 days and larval mortality was significantly higher at this temperature than at 25 and 30 °C. At the latter tem temperatures, mites matured fastest (five and four days, respectively). The net reproductive rate (R0) was 10.8, the mean generation time was (T) 14.4 (SD = 0.273), the intrinsic rate of population increase (rm) was 0.165 (SD = 0.003), and the finite rate of population increase (λ) was 1.12. At 25 °C, H. adleri required 4.2 days to double its population. The results indicate that the thermal conditions prevailing in early spring in central Europe are highly unfavourable for the effective reproduction of H. adleri. The presence of northern populations of this mite is discussed in the context of behavioural thermoregulation mechanisms adapted by its host, P. apterus.

NUMERICAL SIMULATION OF DOUBLE SKIN FACADES IN WINTER CLIMATES

The presented study reveals the analysis of the thermal behaviour of double skin facades (DSF) in winter conditions, using numerical simulation tools. The aim of the study is the development of a 3D simulation model, capable to evaluate the thermal behaviour of the modular elements in the DSF systems. This is essential requirement in the prediction and visualization of the facade’s thermal behaviour in the design stage and in the assessment of the real behaviour of such facade, when the specified modular elements are changed by the customer. The presented numerical simulation model aims to adequately reproduce the resulting set of thermal characteristics of the modular elements, to determine with sufficient accuracy their distribution in the real objects, implemented inthe models in DSF systems. An algorithm is developed in the study and graphical visualization of three models of double facade systems with and without DSF are analysed under winter conditions, using data from a meteorological station located in North-Eastern Bulgaria. A software product was used to represent the processes of heat and mass transfer, in which the corresponding boundary and initial conditions were set, based on which the results and analyses were obtained. The use of such numerical modelling is effective enough to predict the expected thermal behaviour of DSF systems. Thus, when selecting a DSF facade system, awareness of the thermal behaviour is ensured, and the financial efficiency of the project is more easily determined. Such a customized approach not only improves the sustainability and efficiency of buildings, but also satisfies the unique preferences and requirements of the customers.

Changes in waterbird occurrence and abundance at their northern range boundaries in response to climate warming: importance of site area and protection status

AbstractClimate warming is driving changes in species distribution, but habitat characteristics can interact with warming temperatures to affect populations in unexpected ways. We investigated wintering waterbird responses to climate warming depending on habitat characteristics, with a focus on the northern boundary of their non‐breeding distributions where winter climatic conditions are more extreme. At these Nordic latitudes, climate warming is expected to drive positive changes in species occurrence and abundance, with likely differences in species‐specific responses. We analyzed the occurrence and abundance of 18 species of waterbirds monitored over 2,982 surveys at 245 inland wetlands over a 25‐year period in Sweden. We used hierarchical modeling of species communities (HMSC) which enabled us to relate species‐specific changes to both functional traits and phylogenetic relatedness. We investigated occurrence and abundance changes in response to average temperature, temperature anomalies, site area, site protection status (Natura 2000), and land use in agricultural and urban surfaces. Unsurprisingly, both average temperatures and temperature anomalies were the most important variables influencing positively waterbird occurrence and abundance. For 60% of the species, the effect of temperature anomalies was even stronger in large or protected wetlands. Geese and mallard occurred more often at sites surrounded by agricultural and urban surfaces, respectively, but their occurrence in these habitats was not affected by interactive effects with climate warming. Species abundance was greater inside protected areas only for 11% of the species, but occurrence probability was higher inside protected areas for 44% of the species. Overall, we observed that species thermal affinity was a strong predictor for positive species response to temperature anomalies, and that species sharing similar phylogenetic history had similar relationships with environmental variables. Protection of large wetlands and restoration of the surrounding habitats are two targets for climate change adaptation strategies to facilitate future responses of waterbirds to climate warming.

Indications of a changing winter through the lens of lake mixing in Earth’s largest freshwater system

Abstract Global surface freshwater primarily resides in lakes, with the overwhelming majority found in Earth’s largest lakes, thus understanding potential climate change effects in these large lakes is critical. In dimictic lakes, climate change has extended the duration of summer thermal stratification and reduced the length of the ice season. These changes are relatively straightforward to evaluate in smaller, inland lakes. However in large lakes, such as the North American Great Lakes, temporally intermittent and spatially heterogeneous ice cover, and spatial thermal heterogeneity limit the utility of simple ice on-off or mixing classifications; therefore, assessing how climate change is impacting winter conditions in large lakes is challenging. Here, we use in-situ and satellite-derived surface water temperature observations from the North American Great Lakes to overcome these limitations and show that warming air temperatures are driving reductions in the number of winter days, collectively those with either ice cover or inverse thermal stratification, in favor of increases in isothermal conditions for the period 1995 to 2023. We find that on average the Great Lakes are experiencing a loss of 14 winter days per decade. Our results demonstrate how climate change has yielded disproportionate changes in the annual thermal cycle and mixing conditions of Earth’s largest freshwater system and signals the potential for fundamental ecosystem shifts due to a loss of winter.