Urban Climate最新文献_第6页

Imagining adaptation in three Latin American cities: Anchoring definitions of success in local knowledge, values, and histories 想象三个拉丁美洲城市的适应：在当地知识、价值观和历史中锚定成功的定义

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-20 DOI: 10.1016/j.uclim.2026.103043

Ana Terra Amorim-Maia, Marta Olazabal

{"title":"Imagining adaptation in three Latin American cities: Anchoring definitions of success in local knowledge, values, and histories","authors":"Ana Terra Amorim-Maia, Marta Olazabal","doi":"10.1016/j.uclim.2026.103043","DOIUrl":"10.1016/j.uclim.2026.103043","url":null,"abstract":"<div><div>As cities confront intensifying climate risks, attention is growing not only to how adaptation happens and what it delivers, but also to how adaptation success is defined, by whom, and on what terms. This paper draws on qualitative methods, including participatory Theory of Change workshops and semi-structured interviews with local government officials, practitioners, and civil society actors in three Latin American cities – Santiago (Chile), Rosario (Argentina), and Santos (Brazil) - to examine how local actors envision successful urban adaptation in context, unveiling how sociopolitical dynamics shape adaptation goals and processes. Across the cases, success is collectively imagined as the creation of durable public infrastructure that is socially meaningful, institutionally supported, and territorially grounded, and that works over time for those most exposed to risk. These imaginaries of adaptation are shaped by fragmented governance, political volatility, and deeply entrenched legacies of inequality that condition what futures are seen as desirable, feasible, and fair. Our findings show that defining adaptation success locally unfolds through negotiation, compromise, and repeated reflection on values, trade-offs, and safeguards. By surfacing these situated processes, the paper suggests that, in these Latin American cities, reimagining adaptation success involves asking sociopolitical questions that allow for futuring from within context - remaining accountable to place, history, and enduring legacies of inequality - rather than applying universal benchmarks from above. Beyond Latin America, these insights offer globally-relevant lessons for embedding context and learning into adaptation planning and evaluation, particularly in rapidly urbanising and socially diverse regions, where contrasting visions and goals about the future of cities might collide socially, temporally, and spatially.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103043"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148538362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Developing LCZ morphological attenuation-based parameterization prediction models for roadside block-scale PM2.5 concentration 基于LCZ形态衰减的道路块尺度PM2.5浓度参数化预测模型

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 DOI: 10.1016/j.uclim.2026.103075

Lin Liu, Junjie Huang, Tianyu Wang, Jian Hang, Hua Yuan, Lei Jin

{"title":"Developing LCZ morphological attenuation-based parameterization prediction models for roadside block-scale PM2.5 concentration","authors":"Lin Liu, Junjie Huang, Tianyu Wang, Jian Hang, Hua Yuan, Lei Jin","doi":"10.1016/j.uclim.2026.103075","DOIUrl":"10.1016/j.uclim.2026.103075","url":null,"abstract":"<div><div>The PM<sub>2.5</sub> concentration in roadside blocks is greatly reduced through the attenuation effects caused by block morphology. A series of block-scale rapid prediction models (LCPMs) are established based on the Local Climate Zone (LCZ) morphological parameterization scheme. Separate LCPMs are developed for upwind and downwind areas using a dual parameterization scheme, including an inherent attenuation coefficient (<em>ζ</em>) that represents the main diffusion obstruction capacity of each LCZ type, and additional attenuation coefficients (<em>α, β, γ, δ, ε, θ</em>) that modulate the inherent attenuation based on key morphological parameters. These models are resolved and validated using both mobile surveys and fixed station measurements conducted in a case region of Guangzhou under three seasons. Results show that the inherent attenuation coefficient (<em>ζ</em>) ranges from 0.228 to 0.959 of different seasons, and the additional coefficients (<em>α, β, γ, δ, ε, θ</em>) range from −0.85 to 0.96, indicating substantial differences in attenuation effects of different LCZs. Validation metrics show better fitting performance across all seasons (R<sup>2</sup>: 0.74–0.95). Based on the proposed LCPMs, mapping distributions of PM<sub>2.5</sub> concentration are obtained and display seasonal differences with spatially-average values varying from 27.43 μg/m<sup>3</sup> to 59.41 μg/m<sup>3</sup>. In particular, high-density LCZs exhibit the highest PM<sub>2.5</sub> concentrations during peak traffic hours, with values exceeding 90 μg/m<sup>3</sup> in winter. Then kernel density estimation, hotspot detection and spatial auto-correlation mapping results all emphasize the significant spatial heterogeneity. Finally, air quality problem areas are identified according to PM<sub>2.5</sub> concentration threshold and appropriate street tree planting strategies are applied to relieve air pollution.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103075"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148692935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Urban flooding in a tropical coastal environment: Rainfall-impact patterns for early warning 热带沿海环境中的城市洪水：早期预警的降雨影响模式

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-08-07 DOI: 10.1016/j.uclim.2026.103091

Hanna Soares Viana, Fabricio Polifke

{"title":"Urban flooding in a tropical coastal environment: Rainfall-impact patterns for early warning","authors":"Hanna Soares Viana, Fabricio Polifke","doi":"10.1016/j.uclim.2026.103091","DOIUrl":"10.1016/j.uclim.2026.103091","url":null,"abstract":"<div><div>Urban flooding disrupts mobility and municipal operations in large coastal cities, yet rainfall information and impact records are often analyzed separately. Fifteen-minute rainfall from 33 rain gauges is integrated with 4868 georeferenced, operationally classified urban flooding occurrences in Rio de Janeiro to characterize spatiotemporal impact patterns and to develop a rainfall-impact pairing framework with preliminary intensity-duration thresholds. Rainfall time series were segmented into independent events using a 6 h minimum dry interval; each event was described by duration and maximum 1 h intensity. Occurrence records were cleaned, assigned to three severity levels based on water depth and traffic disruption, and paired with rainfall using Thiessen polygon influence areas and timing overlap. Results show that moderate-severity road ponding dominates the database (86.6%), while high-severity street flooding accounts for 9.6%. Event persistence increases with severity: pooled low- and moderate-severity events have a median duration of 1.95 h (90th percentile 5.71 h), whereas high-severity events have a median of 2.99 h (90th percentile 8.36 h). Occurrences peak in summer (2330 events) and concentrate in late afternoon and evening during warm seasons, with persistent spatial hotspots and broader footprints for high-severity impacts. Network coverage is strong (median distance to nearest gauge 1.81 km; 90% within 3.59 km), supporting robust pairing at the city scale. The framework delivers evidence on when and where impacts cluster, and provides preliminary station-level intensity-duration thresholds, with antecedent soil moisture conditioning reducing false alarms, as a first step toward locally meaningful early warning criteria.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103091"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The role of soil moisture and shading in influencing the capacity of urban street trees to reduce heat stress 土壤水分和遮荫对城市行道树减少热胁迫能力的影响

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-08-07 DOI: 10.1016/j.uclim.2026.103086

Ricard Segura-Barrero, Alberto Martilli, E. Scott Krayenhoff, Alba Badia, Gara Villalba

{"title":"The role of soil moisture and shading in influencing the capacity of urban street trees to reduce heat stress","authors":"Ricard Segura-Barrero, Alberto Martilli, E. Scott Krayenhoff, Alba Badia, Gara Villalba","doi":"10.1016/j.uclim.2026.103086","DOIUrl":"10.1016/j.uclim.2026.103086","url":null,"abstract":"<div><div>Street trees can significantly reduce urban heat through shading and transpirative cooling, but their effectiveness may be compromised during heat waves with dry soil conditions. This study assesses the cooling potential of street trees using a modified BEP-Tree model incorporating soil moisture dynamics and thermos-physiological indices like the Universal Thermal Climate Index (UTCI). The model is first validated with a micrometeorological measurement campaign during hot summer days in a town in the Metropolitan Area of Barcelona, Spain, yielding a good model performance representing the spatial variability of the mean radiant temperature and UTCI inside the studied neighbourhood. Then, BEP-Tree is used to simulate two highly-compact neighbourhoods with differing tree densities in the city of Barcelona, combined with varying soil moisture levels during a heat wave. Results show that street trees in moist soil reduced air temperatures by an average of 1.2 ± 0.4 °C, leading to UTCI reductions up to 3.2 °C. Albeit air-cooling effects were reduced under dry-soil conditions, shade-driven temperature reductions remained substantial, retaining 71–97% of the cooling effect. The findings highlight the importance of tree shading rather than air-cooling in maximising the cooling capabilities of street trees during extreme heat events. Additionally, it is crucial to maintain adequate soil moisture to preserve tree health and substantial foliage to provide consistent microclimatic benefits, particularly during periods of strong heat stress.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103086"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Scale-dependent urban morphological associations with neighborhood heat stress in a hot-humid city: Evidence from mobile measurements in Nanning, China 在湿热城市中，尺度依赖的城市形态与邻里热应激的关联：来自中国南宁移动测量的证据

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-22 DOI: 10.1016/j.uclim.2026.103064

Yuya Xiong, Xiaxuan He, Huabin He, Mingqi Yan, Hong Chen

{"title":"Scale-dependent urban morphological associations with neighborhood heat stress in a hot-humid city: Evidence from mobile measurements in Nanning, China","authors":"Yuya Xiong, Xiaxuan He, Huabin He, Mingqi Yan, Hong Chen","doi":"10.1016/j.uclim.2026.103064","DOIUrl":"10.1016/j.uclim.2026.103064","url":null,"abstract":"<div><div>Urban heat stress is intensified by rapid urbanization and climate warming, especially in hot-humid cities where humidity strongly affects thermal exposure. Using mobile monitoring data from Nanning, China, this study developed a common-feature two-step framework that reconstructed air-temperature and relative-humidity residuals before calculating Heat Index. It was benchmarked against background-only, direct Heat Index, and direct residual Heat Index strategies under spatially grouped validation. Predictors included urban morphology, land cover, road networks, green-blue context, and building structure. The background-only baseline substantially underestimated Heat Index (RMSE = 3.296 °C; bias = −3.034 °C). The two-step reconstruction achieved high independent-test accuracy (R<sup>2</sup> = 0.992; RMSE = 0.566 °C; MAE = 0.433 °C), comparable to direct Heat Index and direct residual Heat Index modelling (RMSE = 0.548 °C). Although direct strategies produced marginally lower errors, the two-step framework supports interpretation of separate temperature and relative-humidity pathways. Many leading predictors appeared at 1500–2000 m buffer scales, indicating neighborhood-scale associations. Under the July–August Typical Meteorological Year summer-average 15:00 scenario, local Heat Index increment hotspots were spatially concentrated, with combined temperature–relative-humidity priority zones mainly in central and southern built-up areas.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103064"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

How urban system structure and land use dynamics jointly shape climate vulnerability in Northwestern China over the 21st century 21世纪中国西北地区城市体系结构和土地利用动态如何共同影响气候脆弱性

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-27 DOI: 10.1016/j.uclim.2026.103066

Wei Zhou, Yan Wen, Shanshan Jia, Xin Fu, Tongtong Li, Jiarong Zhu, Xinhao Wang

{"title":"How urban system structure and land use dynamics jointly shape climate vulnerability in Northwestern China over the 21st century","authors":"Wei Zhou, Yan Wen, Shanshan Jia, Xin Fu, Tongtong Li, Jiarong Zhu, Xinhao Wang","doi":"10.1016/j.uclim.2026.103066","DOIUrl":"10.1016/j.uclim.2026.103066","url":null,"abstract":"<div><div>Northwest China, characterized by ecologically fragile zones and high climate sensitivity, faces increasing population and economic growth under the Belt and Road Initiative, making it critical to balance climate risks and socioeconomic transitions. This study develops a scenario-based framework integrating climate extremes identification, land use simulation, and vulnerability assessment. Five scenarios (baseline, dispersion (DD), polarization (PD), micro-breakthrough, and low-carbon (LC)) are used to examine how regional development pathways shape spatially heterogeneous vulnerabilities. During 2071–2100, under SSP2–4.5 compared with SSP5–8.5, extreme hot days decrease by 42.42%, extreme cold days increase by 3.41%, drought declines by 5.27%, and late spring coldness rises sharply by 113.41%. By 2100, developed land expands by 18.99–87.64% across scenarios, while cropland declines by up to 3.87%; PD and LC better preserve ecological land, whereas grassland shrinks by 11.25% in the baseline. Vulnerability shows pronounced spatial heterogeneity across cities, driven primarily by climate conditions in the west and population pressure in the east, with values ranging from 0.78 in Yushu (DD, SSP5–8.5) to 3.96 in Turpan (LC, SSP2–4.5). Policy interventions are most effective in the western and southern regions, with PD producing the greatest vulnerability reduction and substantially narrowing inter-city disparities, while LC results in modest improvements.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103066"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancement of risk-based metaheuristic flood evacuation route optimisation algorithms 基于风险的元启发式洪水疏散路线优化算法的改进

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-24 DOI: 10.1016/j.uclim.2026.103047

Chuannan Li, Changbo Jiang, Man Yue Lam, Ruixuan Wu, Junqiang Xia, Reza Ahmadian

{"title":"Enhancement of risk-based metaheuristic flood evacuation route optimisation algorithms","authors":"Chuannan Li, Changbo Jiang, Man Yue Lam, Ruixuan Wu, Junqiang Xia, Reza Ahmadian","doi":"10.1016/j.uclim.2026.103047","DOIUrl":"10.1016/j.uclim.2026.103047","url":null,"abstract":"<div><div>Human activities have led to global warming, triggering frequent natural disasters, especially floods, which have caused significant harm to people. Evacuation is an effective measure to enhance urban resilience against flood. Research on optimising evacuation routes, particularly for pedestrian evacuation, is limited. Metaheuristic route optimisation algorithms, such as Ant Colony Optimisation (ACO), Genetic Algorithm (GA), Particle Swarm Optimisation algorithm (PSO) and Sparrow Search Algorithm (SSA), are gaining attention due to their flexibility, high computational efficiency, and adaptability to various scenarios, yet they have not been applied to flood evacuation problems. This research improves metaheuristic algorithms to optimise flood evacuation routes by revising and including the flood risk associated with the route as a part of the objective function. The improved algorithms developed in this study include Improved ACO (IACO), Improved GA (IGA), Improved PSO (IPSO) and Improved SSA (ISSA). The improved algorithms were incorporated into a flood evacuation research framework comprising flood modelling, flood hazard rating, and evacuation route optimisation and applied to the 2023 flood event in York, UK. The improved metaheuristic algorithms effectively navigate road networks and narrow streets, optimising pedestrian evacuation routes and avoiding high-risk flood zones. The IACO and IGA produced the route with the lowest risk and fewest turns, respectively. The IPSO algorithm was the most computationally efficient, generating the routes at the highest speed, while the ISSA showed the slowest speed. This generalisable framework integrates flood risk with infrastructure connectivity to optimise evacuation routes that enhance urban resilience and sustainability.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103047"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatial heterogeneity of net thermal effects driven by three-dimensional urban expansion: Evidence from Wuhan, China 城市三维扩张驱动的净热效应空间异质性：来自武汉的证据

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-31 DOI: 10.1016/j.uclim.2026.103072

Wen Zhang, Limin Jiao, Bingjie Li, Haoran Zhang, Yaolin Liu

{"title":"Spatial heterogeneity of net thermal effects driven by three-dimensional urban expansion: Evidence from Wuhan, China","authors":"Wen Zhang, Limin Jiao, Bingjie Li, Haoran Zhang, Yaolin Liu","doi":"10.1016/j.uclim.2026.103072","DOIUrl":"10.1016/j.uclim.2026.103072","url":null,"abstract":"<div><div>Modern cities are undergoing both horizontal and vertical expansion, but the background-adjusted thermal responses associated with different three-dimensional (3D) growth types along urban gradients remain poorly understood. To address this gap, this study integrated multi-temporal Local Climate Zone (LCZ) maps and Landsat-derived daytime land surface temperature (LST) data for Wuhan, China, from 2005 to 2020. A difference-in-differences (DiD) framework was then applied, using morphologically stable units as the background reference, to quantify the net LST responses associated with major 3D urban expansion types. Results showed that the net warming associated with 3D urban morphological change followed a pronounced inverted U-shaped gradient, with mean warming intensities of 1.11, 2.99, 3.37, and 1.43 °C in the Core, Inner Urban, Suburban, and Urban Fringe, respectively. This pattern was consistently observed across different expansion types, indicating that the thermal response of a given 3D expansion mode was not fixed, but varied systematically with the urban gradient context. Overall, compact verticalization (CV) and open verticalization (OV) were associated with the strongest warming peaks, especially in the rapidly urbanizing Suburban zone where production- and construction-related land transformations were concentrated, whereas pure verticalization (PV) and OV in the urban Core showed localized cooling or weak warming responses. By quantifying background-adjusted LST responses to alternative 3D urban growth modes along the urban gradient, this study provides a transferable framework for assessing how urban expansion pathways reshape surface thermal conditions across contrasting spatial contexts and offers evidence for climate-adaptive, zone-specific urban redevelopment and land-use planning.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103072"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vertical variations and source identification of PM2.5 and PM10–2.5–bound elements around a high–rise building in urban Bangkok, Thailand 泰国曼谷市区高层建筑周围PM2.5和pm10 - 2.5边界元素的垂直变化及来源识别

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 Epub Date: 2026-07-25 DOI: 10.1016/j.uclim.2026.103068

Siriphat Intrakun, Narut Sahanavin, Tassanee Chetwittayachan

{"title":"Vertical variations and source identification of PM2.5 and PM10–2.5–bound elements around a high–rise building in urban Bangkok, Thailand","authors":"Siriphat Intrakun, Narut Sahanavin, Tassanee Chetwittayachan","doi":"10.1016/j.uclim.2026.103068","DOIUrl":"10.1016/j.uclim.2026.103068","url":null,"abstract":"<div><div>This study investigated the vertical variations, elemental compositions, and source apportionments of PM<sub>2.5</sub> and PM<sub>10–2.5</sub>. Sampling was conducted at three heights (4.5, 51.5, and 138.5 m) on a high-rise building during rainy, winter, and summer periods. PM<sub>2.5</sub> showed significant differences among periods, with the highest in winter (43.49 ± 10.74 μg/m<sup>3</sup>), followed by the rainy (31.70 ± 12.83 μg/m<sup>3</sup>) and summer (17.16 ± 5.82 μg/m<sup>3</sup>) periods. PM<sub>10–2.5</sub> concentrations followed a similar trend, averaging 16.53 ± 2.43, 14.61 ± 4.33, and 12.79 ± 2.54 μg/m<sup>3</sup>, respectively, in those periods. Wind speed and BLH were negatively correlated with PM<sub>2.5</sub> concentrations (<em>r</em> = −0.701 and − 0.501), respectively. PM<sub>2.5</sub>/PM<sub>10</sub> ratios across heights and periods ranged from 0.56 to 0.72. PM<sub>2.5</sub> showed no significant vertical differences in concentration and elemental composition. While PM<sub>10–2.5</sub> concentrations at 138.5 m were slightly elevated relative to 4.5 m during the rainy period (2.88 ± 3.82 μg/m<sup>3</sup>), they were markedly lower than those at 4.5 and 51.5 m during winter (7.37 ± 1.34 and 6.99 ± 1.26 μg/m<sup>3</sup>, respectively). Elemental composition of PM<sub>10–2.5</sub> also showed significant height- and period-dependent variations. Four potential sources of PM<sub>2.5</sub> were interpreted: fossil fuel/coal combustion-related sources (67.04%), industrialrelated emissions (17.63%), soil-related dust (11.18%), and brake and tire wear (4.15%). For PM<sub>10–2.5</sub>, the potential sources were traffic-influenced resuspended road dust (45.69%), industrial-related emissions (14.54%), brake and tire wear (24.44%), and mixed marine/crustal sources (15.33%). These findings enhance understanding of size-specific vertical patterns of fine and coarse particles in open urban high-rise environments.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103068"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148635864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced solar radiation diffusion in the urban environment: A case study over Houston, Texas 城市环境中增强的太阳辐射扩散：以德克萨斯州休斯顿为例

IF 7.5 2区工程技术

Urban Climate Pub Date : 2026-08-01 DOI: 10.1016/j.uclim.2026.103033

Stephen Willis, Yangyang Xu, Xinxin Sui, Leiqiu Hu, You Joung Kim, Robert D. Brown

{"title":"Enhanced solar radiation diffusion in the urban environment: A case study over Houston, Texas","authors":"Stephen Willis, Yangyang Xu, Xinxin Sui, Leiqiu Hu, You Joung Kim, Robert D. Brown","doi":"10.1016/j.uclim.2026.103033","DOIUrl":"10.1016/j.uclim.2026.103033","url":null,"abstract":"<div><div>Although solar radiation has been considered in assessing human sensation of heat extremes in urban climate studies, the spatiotemporal variation in the ratio of diffuse horizontal irradiance to global horizontal irradiance, termed as Diffuse Fraction (k<sub>d</sub>), remains unquantified. The importance of this variable to human thermal comfort estimation and photovoltaic energy motivates this study. Using the high-resolution (2 km, hourly) satellite-derived solar radiation flux data from the National Solar Radiation Database (NSRDB), we examine the mean k<sub>d</sub> over southeast Texas for the years 2019–2022. We identify a robust urban-rural contrast in k<sub>d</sub> around the metropolitan area of Houston. The enhancement of k<sub>d</sub> is strongest during the warm season (June to September) and during the local afternoon (1 pm to 4 pm). Furthermore, we examine the relationship between the k<sub>d</sub> pattern and multiple potential contributing factors, such as surface albedo (as a proxy of urban-rural land characteristics), cloud frequency, aerosols, and ozone. Among all factors, cloud frequency shows a strong, positive spatiotemporal correlation with the mean k<sub>d</sub>. Satellite-derived cloud frequency itself demonstrates a statistically significant enhancement over the Houston urban area. Future studies can assess whether this phenomenon exists in other cities and to what extent it impacts human heat sensation.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"68 ","pages":"Article 103033"},"PeriodicalIF":7.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148657519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0