Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102481
Liudan Jiao , Zhirui Luo , Bowei Han , Liu Wu , Xiaosen Huo , Yu Zhang , Ya Wu
{"title":"Resilient urbanization assessment framework: A new perspective on urban resilience","authors":"Liudan Jiao , Zhirui Luo , Bowei Han , Liu Wu , Xiaosen Huo , Yu Zhang , Ya Wu","doi":"10.1016/j.uclim.2025.102481","DOIUrl":"10.1016/j.uclim.2025.102481","url":null,"abstract":"<div><div>Urban resilience (UR) and New-type urbanization (NU) are essential driving forces for sustainable urban development. The positive coordination between UR and NU is of great significance for the high-quality construction of cities. However, limited studies have focused on the direct link between UR and NU, ignoring the relationship between these two systems. Therefore, this study proposes a quantitative method for evaluating resilient urbanization (RU) by investigating the coordination between UR and NU. A resilient urbanization elasticity coefficient <span><math><msub><mi>I</mi><mi>RU</mi></msub></math></span> defined by the change rate of UR and NU, and a <span><math><mo>∆</mo><mi>UR</mi><mo>−</mo><mo>∆</mo><mi>NU</mi></math></span> coordinate system was developed based on this coefficient, which can determine whether urbanization is resilient by the value of <span><math><msub><mi>I</mi><mi>RU</mi></msub></math></span> or from the <span><math><mo>∆</mo><mi>UR</mi><mo>−</mo><mo>∆</mo><mi>NU</mi></math></span> coordinate system. Subsequently, the Entire-array-polygon graphical method and GM(1,1) model were combined to calculate UR, NU and RU. Then, four municipalities in China were selected for a case study, and the results revealed that the proposed resilient urbanization elasticity coefficient could help to examine whether the urbanization process is resistant. At the same time, this coefficient can flexibly set the examination period to evaluate the performance of resilient urbanization in any period. The established coordinate system provides an accurate platform for horizontal and vertical comparison of multiple cities, which can help make correct decisions.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102481"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185198","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102489
Sichan Du , Lu Zhuo , Elizabeth J. Kendon , Dawei Han
{"title":"Exploring suitable domain size for high-resolution urban rainfall simulation","authors":"Sichan Du , Lu Zhuo , Elizabeth J. Kendon , Dawei Han","doi":"10.1016/j.uclim.2025.102489","DOIUrl":"10.1016/j.uclim.2025.102489","url":null,"abstract":"<div><div>High-resolution urban rainfall simulation is useful for understanding the interaction between urbanisation and local weather as well as the impact of climate change over cities and the impact of adaptation measures such as urban greening. Previous studies on mesoscale Numerical Weather Prediction (NWP) modelling have largely focused on spatial resolution and other aspects (e.g., spin-up time and model parameterisations), with limited investigations on how to determine a suitable domain size. Domain size is likely an important factor when the spatial resolution of modelling is within convection-permitting regime (less than 5 km). In this study, 64 summer domain tests are simulated with the Weather Research and Forecasting (WRF) model, over Newcastle upon Tyne, with ERA5 as input data and a radar product from the UK Met Office for validation. Using an integrated evaluation indicator, alongside spatial distribution maps, it has been found that too large or too small domain sizes both have negative impacts on the simulation results and an optimal domain size for the events here is identified. We find that domain size has a stronger influence on the event simulation than changing grid resolution within the range 1–4.5 km and thus should be a primary consideration. We also find that, for more accurate simulation, smaller domain sizes are better suited to heavy rainfall events than to lighter ones. In a similar way, smaller domain sizes perform better for rainfall events that cover larger spatial areas. Although the optimal domain size identified here is specific to the region/season, the sensitivities and relative influences are expected to be more generally applicable and show the importance of testing domain sizes before embarking on production simulations.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102489"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222515","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102477
Sokol Dervishi, Jaçela Merollari, Ina Dervishi
{"title":"Assessing microclimate and solar potential in courtyard morphologies: A comparative study of European urban blocks","authors":"Sokol Dervishi, Jaçela Merollari, Ina Dervishi","doi":"10.1016/j.uclim.2025.102477","DOIUrl":"10.1016/j.uclim.2025.102477","url":null,"abstract":"<div><div>Urbanization perpetually reshapes cities including their urban morphology to adapt to the environmental changes. In Europe, there is a growing emphasis on sustainable architecture and urban planning with low energy consumption and less carbon emissions. Urban morphology and its parameters highly influence the energy consumption of buildings, but there is a study gap in understanding the interplay between them. Many European countries have implemented guidelines and regulations to promote sustainable building designs, however, urban morphology's role in sustainability is emerging, with much to explore.</div><div>This research explores the impact of different urban morphologies of existing residential buildings on their courtyards' solar potential and thermal comfort, in four European climatic contexts, as well as the differences that landscape materials make on UTCI values of these courtyards. Three different morphologies are analyzed through simulations in an urban scale. The results highlight that grassy lawn and concrete pavement make great difference of UTCI, in the oceanic climate with a maximum difference of 12.7 °C, followed by the humid subtropical climate with 11.9 °C, while the smallest difference is 5.7 °C in the humid continental climate. The findings will establish recommendations on energy optimization principles for architects and urban planners in urban design scenarios.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102477"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222516","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102494
Abdul Rahman, Sreeja Pekkat
{"title":"Temperature magnitude duration frequency curves to unravel temperature extremes incorporating climate change across India","authors":"Abdul Rahman, Sreeja Pekkat","doi":"10.1016/j.uclim.2025.102494","DOIUrl":"10.1016/j.uclim.2025.102494","url":null,"abstract":"<div><div>This study demonstrated the utility of temperature magnitude duration frequency (TMDF) curves for quantifying and comparing the risk of extreme temperatures in 41 cities across India, classified under Koppen-Geiger climate zones. Results from all the cities reveal that as the duration of the event increases, there is a decrease in the magnitude of extreme temperature events for the same return period. The spatial mean extreme temperature events were highest for cities in the temperate, dry, and hot summer (Csa) climate zone and lowest in the tropical monsoon (Am) climate zone. The cities falling under the ‘Am’ and ‘Csa’ climate zones depicted an average increase of 4.7 °C and 3.4 °C respectively, for far-future SSP585 climate scenario. The cities under arid, steppe, and hot ‘BSh’, temperate, dry, and hot summer ‘Csa’ and temperate, dry winter, and hot summer ‘Cwa’ climate zones also exhibited extreme temperature events with prolonged duration and increased frequency. A 10-year return period event lasting 10 days shows a significant increase of 0.4 °C to 2.6 °C in the national capital of India, considering far-future climate scenarios. The future climate scenario-based TMDF provide insights to the policymakers and urban planners to target zone-specific mitigation measures against temperature extremes.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102494"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253539","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102475
Xuan Tong Nguyen , Thi Tuyen Le , Kim Hoa Nguyen , Thi Thanh Thao Nguyen , Tang Phuc Khang Luu
{"title":"Assessing air pollution and seasonal variations in Dong Nai Province, Vietnam: A geospatial analysis of key air quality parameters (2022−2023)","authors":"Xuan Tong Nguyen , Thi Tuyen Le , Kim Hoa Nguyen , Thi Thanh Thao Nguyen , Tang Phuc Khang Luu","doi":"10.1016/j.uclim.2025.102475","DOIUrl":"10.1016/j.uclim.2025.102475","url":null,"abstract":"<div><div>Air pollution poses a significant threat to human health, particularly in rapidly urbanizing developing countries like Vietnam. This study assessed air quality in 55 locations across Dong Nai province using periodic intermittent monitoring during the dry and rainy seasons of 2022–2023. Key air quality parameters, including total suspended particulate matter (TSP), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO), were measured. Geostatistical analysis using the Geographical Information System (GIS) and inverse distance weighting (IDW) was employed to map and predict air pollution levels. Results showed that TSP and NO₂ concentrations exceeded the annual limits of QCVN 05:2023/BTNMT, with higher levels during the dry season and an increasing trend over two years. The highest TSP concentration (202.53 μg/m<sup>3</sup>) was recorded in solid waste treatment areas in the dry season of 2023, while the lowest (25.21 μg/m<sup>3</sup>) occurred in background areas in 2022. CO levels were highest in airport areas (6126.15 μg/m<sup>3</sup> in 2023) and lowest in solid waste treatment areas during the rainy seasons (100.00 μg/m<sup>3</sup>). A strong positive correlation (<em>r</em> = 0.90, <em>p</em> < 0.01) between noise and CO was observed, suggesting traffic as a major pollution source, though no significant correlations between other air parameters were found. This demonstrates that human activities, including traffic and daily activities, are the primary cause of the current air pollution in Dong Nai province.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102475"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184181","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102491
Hanbing Xiong , Tianhao Shi , Yongjia Wu , Ruiyue Xia , Xitong Yuan , Renaud de Richter , Wei Li , Yueping Fang , Nan Zhou , Wenyu Li , Chong Peng , Tingzhen Ming
{"title":"Numerical simulation of the effect of solar chimneys on NOx-O3 photochemical reaction and ventilation in urban street canyon","authors":"Hanbing Xiong , Tianhao Shi , Yongjia Wu , Ruiyue Xia , Xitong Yuan , Renaud de Richter , Wei Li , Yueping Fang , Nan Zhou , Wenyu Li , Chong Peng , Tingzhen Ming","doi":"10.1016/j.uclim.2025.102491","DOIUrl":"10.1016/j.uclim.2025.102491","url":null,"abstract":"<div><div>The complex interaction between pollutants and insufficient ventilation in urban street canyon presents significant challenges to the creation of a healthy urban environment. This study proposed the innovative application of solar chimneys (SCs) to improve airflow structure and air quality in the confined space considering NO<sub>x</sub>-O<sub>3</sub> photochemical reaction mechanism. The influences of ambient wind, solar radiation at three local solar times (LSTs), and the SCs on NO<sub>x</sub> diffusion and ventilation performance in street canyon were revealed by developing a mathematical model. The results demonstrated that the uneven temperature distribution induced by solar radiation at the LSTs significantly influences both the NO<sub>x</sub>-O<sub>3</sub> photochemical reaction and the airflow structure within the street canyon. The deleterious effects of thermal buoyancy on the airflow structure were mitigated by the integration of the SCs. The reaction shifted toward the conversion of NO<sub>2</sub> to NO as the temperature decreased. The integration of SCs resulted in a maximum temperature reduction of 6.01 K in the pedestrian respiratory zone and demonstrated maximum removal efficiencies of 66.12 % for NO and 70.65 % for NO<sub>2</sub>. The NO<sub>x</sub> levels on the leeward side initially increased and then decreased as the ambient wind strengthened, whereas the NO<sub>x</sub> levels on the windward side consistently decreased. This research verifies the feasibility of utilizing the SCs to enhance the street canyon environments and offers a viable strategy for promoting healthy and sustainable urban.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102491"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230975","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102488
Haoqing Xu , Xinmiao Shi , Aizhao Zhou , Wei Wang , Nan Zhang , Pengming Jiang , Shunqing Liu
{"title":"Study on durability characteristics of solidified sediment in semi-dynamic acid soaking environment","authors":"Haoqing Xu , Xinmiao Shi , Aizhao Zhou , Wei Wang , Nan Zhang , Pengming Jiang , Shunqing Liu","doi":"10.1016/j.uclim.2025.102488","DOIUrl":"10.1016/j.uclim.2025.102488","url":null,"abstract":"<div><div>In order to achieve the goal of resource utilization of Municipal Solid Waste Incineration (MSWI) fly ash and sediment, the MSWI fly ash and cement are used to solidify sediment as the intermediate cover material in landfill. The engineering properties and evolution of durability characteristics of solidified sediment were studied under semi-dynamic immersion of acid rain and acid leachate simulated by hydrochloric acid by unconfined compressive strength (UCS), direct shear (DS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) tests. The results show that the UCS strength increases with the increase of curing age and the cement content. Strong acid environment (pH = 2) degrades the service performance of the solidified sediment, resulting in secondary slime of the sample leading to reduction in UCS strength, mass, and increase in moisture content. However, weak acidity environment (pH = 4) and neutral environment (pH = 7) lead to increase in UCS strength, stabilization of mass and moisture, and improvement of service performance of the solidified sediment. The main hydration products calcium silicate hydrate (C-S-H), carbonate and calcium sulfate facilitates the development of strength and acid buffering capacity of the solidified sediment. Under soaking in semi-dynamic simulation of acid erosion, the solidified sediment exhibits satisfactory durability. As the intermediate covering material of landfill, it can not only better buffer acid rain and leachate erosion, effectively block the contact between garbage and acid rain, leachate and the ground, reduce the impact on urban climate, but also use MSWI fly ash to replace part of the cement to reduce the use of cement, reduce CO<sub>2</sub> and dust emissions in the production process, with good environmental benefits.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102488"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241300","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}
{"title":"Quantifying the cooling effects of blue-green spaces across urban landscapes: A case study of Kathmandu Valley, Nepal","authors":"Saurav Bhattarai , Prabhat Banjara , Vishnu Prasad Pandey , Anil Aryal , Prajal Pradhan , Firas Al-Douri , Nawa Raj Pradhan , Rocky Talchabhadel","doi":"10.1016/j.uclim.2025.102493","DOIUrl":"10.1016/j.uclim.2025.102493","url":null,"abstract":"<div><div>Mitigating extreme heat is crucial for enhancing the livability and sustainability of urban centers in the face of rising temperatures. A sound understanding of temperature variation is necessary to effectively design heat mitigation strategies. In this study, we develop a framework to quantify the cooling effects of blue-green spaces, such as urban forests, parks, and ponds, through the integration of remote sensing and geo-spatial modeling. We then employ the framework across urbanized, transitional, and vegetation-dominated zones in the Kathmandu Valley, Nepal. Across the valley, our results reveal distinct cooling signatures for each type of natural entity, with urban forests exhibiting the greatest cooling potential (up to 1.2 °C reduction), followed by urban parks (0.9 °C) and ponds (0.85 °C). This hierarchical cooling effect can be attributed to the complex interactions between these features and urban heat transfer processes: forests provide more effective barriers against lateral heat movement through their dense canopy structure and multiple vegetation layers, while also maximizing evapotranspiration cooling; parks offer varying degrees of cooling based on their vegetation density and composition; and ponds, while effective through evaporative cooling, are more susceptible to heat absorption from surrounding urban surfaces. Notably, the cooling efficiency of these blue-green spaces is significantly influenced by their size and the surrounding urban context, with the greatest cooling benefits observed in vegetation-dominated zones. However, in highly urbanized areas, the cooling potential of these blue-green spaces is diminished, underscoring the need for context-specific heat mitigation strategies. Our findings highlight the importance of strategically integrating natural entities' size and location into urban planning zoning, plans, and policies to maximize their cooling benefits and offer valuable insights for urban planners worldwide as they strive to enhance resilience. Future research should focus on developing cost-effective implementation strategies and quantifying additional co-benefits of blue-green infrastructure beyond temperature reduction.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102493"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241303","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102468
Weishi Zhang , Ying Xu , Federico Cugurullo , David G. Streets , Can Wang
{"title":"Spatiotemporal interaction between new-type urbanization and low-carbon technology development on curbing urban SO2 pollution in China","authors":"Weishi Zhang , Ying Xu , Federico Cugurullo , David G. Streets , Can Wang","doi":"10.1016/j.uclim.2025.102468","DOIUrl":"10.1016/j.uclim.2025.102468","url":null,"abstract":"<div><div>The spatiotemporal heterogeneity of new-type urbanization in Chinese cities, with its emphasis on ecological development, interacts with the low-carbon technology development (LCT), a critical initiative for achieving carbon peak and neutrality targets. This interplay may lead to varied outcomes in air pollution control. This study investigates the spatiotemporal interplay between the four innovation priorities of new-type urbanization and LCT in influencing urban sulfur dioxide (SO₂) emissions and emission intensity. By constructing the Geographically and Temporally Weighted Regression (GTWR) model, we estimate the spatiotemporally varying coefficients across 294 cities and 18 urban agglomerations in China from 2012 to 2022. Our findings reveal that: (1) LCT has a strengthening effect on the inhibitory effect of new-type urbanization on urban industrial SO<sub>2</sub> emission intensity across all Chinese cities and in 73 % of the cities for SO<sub>2</sub> emissions. (2) LCT alleviates the energy rebound effect caused by population and land use changes accompanying new-type urbanization. (3) In 41 % of the cities, the relationship between economic new-type urbanization and SO<sub>2</sub> emissions was identified to be an inverted U-shaped correlation. (4) Urban agglomerations have better SO<sub>2</sub> control impacts during their new-type urbanization process, where the strengthening effect of LCT on inhibiting SO<sub>2</sub> emissions is 1.6 times higher. This study provides empirical evidence to inform nuanced new-type urbanization strategies and targeted SO₂ pollution control measures at city and urban agglomeration scales.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102468"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203487","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}
Urban ClimatePub Date : 2025-06-01DOI: 10.1016/j.uclim.2025.102473
Prince Vijay , Harish C. Phuleria
{"title":"Examining light absorbing characteristics of fine particulate matter during winter 2019–20 in residential areas of metropolitan cities in India","authors":"Prince Vijay , Harish C. Phuleria","doi":"10.1016/j.uclim.2025.102473","DOIUrl":"10.1016/j.uclim.2025.102473","url":null,"abstract":"<div><div>Fine particle mass concentrations and its carbonaceous characteristics are not adequately examined in urban residential outdoor locations in low and middle-income countries such as India. This study was conducted across three Indian metropolitan cities - Mumbai, Bangalore, and Delhi, during the winter period of 2019–2020. We measured PM<sub>2.5</sub>, outside residences in each city and characterized the optical and chemical properties of the aerosols. PM<sub>2.5</sub> mass concentrations were 131.3 ± 71.8 for Mumbai, 75.2 ± 33.4 for Bangalore, and 192.2 ± 75.5 μg/m<sup>3</sup> for Delhi, showing significant differences between cities and not within cities (<em>p</em> < 0.05). This trend was similar for carbonaceous constituents as well. Aerosol absorption (b<sub>abs</sub>) and elemental carbon (EC) showed a moderate positive correlation (0.19–0.45) at 880 nm, which implies EC is the dominant component of absorption in PM<sub>2.5</sub>. Using the city-specific mass absorption cross-section (MAC ranging 8.8–12.0) for three cities, BC concentrations estimated were 14.3 ± 8.4 for Mumbai, 8.7 ± 5.6 in Bangalore and 17.0 ± 10.5 μg/m<sup>3</sup> in Delhi. High agreement (>0.70) between b<sub>abs</sub> and water-soluble organic carbon (WSOC) showed dominant absorption by brown carbon (BrC). Average angstrom absorption exponent (AAE) ∼1.3 across the study sites showed the influence of vehicle-emitted particles on light absorbing capacity. Ratio of b<sub>abs</sub>,370/b<sub>abs</sub>,880 (1.1 to 4.7) indicated a significant contribution of BrC to light absorption coefficient. OC/EC (1.1–11.0) and OC/K<sup>+</sup> ratio (1.0–51.0) suggested the differential impact from various sources. Hence understanding the nature of aerosols in urban residential atmospheres allows us to assess the impact of source-specific emissions and warrants wider control and elimination measures.</div></div>","PeriodicalId":48626,"journal":{"name":"Urban Climate","volume":"61 ","pages":"Article 102473"},"PeriodicalIF":6.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203485","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}