Past Events #12

全球城市变暖遥感

占文凤 (Nanjing University): 9 pm, 17th May, Saturday

Abstract:

随着气候变化和城市化进程加速，城市变暖速度快于自然郊区，加剧了居民热胁迫。卫星热红外遥感是监测大范围城市变暖的有效手段。本报告聚焦“城市变暖遥感”主题，主要探讨：（1）空间精细化视角下全球城市内部地表变暖和绿变趋势；（2）居民健康视角下全球南方城市湿热变化趋势及其对城市褐变的响应；（3）更长时序以及垂向剖面视角下全球城市热岛演变趋势；（4）多元城市化路径视角下全球城市核心区热环境演变特征。

Biograph:

占文凤，教授，南京大学国际地球系统科学研究所所长助理，IEEE GRSL副编辑；主要从事卫星热红外遥感与城市环境遥感研究，主持国家自然科学基金等项目在内的国家或省部级项目10余项；在Nature Climate Change, Nature Cities, Science Bulletin, Bulletin of the American Meteorological Society, Geophysical Research Letters, Remote Sensing of Environment等期刊发表论文100余篇；获李小文遥感科学奖、国际城市气候协会Timothy Oke奖、测绘科技进步奖一等奖、全国高校GIS教学成果奖特等奖等；入选江苏省杰青、国家级青年人才计划与高校GIS十大创新人物等。

Past Events #11

边界层气象和城市气象在低空经济中的应用与挑战

张宁 (Nanjing University): 9 pm, 26th Apr, Saturday

Abstract:

低空经济是新质生产力的重要组成部分，是我国未来经济发展的新增长点。低空经济的本质是空中交通，低空气象环境对低空空域利用的安全性和经济性有直接影响。低空航路气象保障是低空基础建设的核心环节之一。全面分析城市灾害性天气和边界层气象特征是保证航路规划的科学性，减少后期的运行成本和风险的重要一环，也是低空气象预警预报服务的基础。本报告结合在深圳、苏州等城市的探索，介绍地基遥感探测、多尺度数值模拟等技术在低空气象特征和适航性分析，航路与起降区设置，低空气象探测网络保障建设等方面的初步应用和面临的挑战。

Biograph:

张宁，南京大学大气科学学院教授，博导，中国气象学会城市气象学专业委员会副主任委员，中国气象学会航空航天气象学专业委员会委员，中国空气动力学会风工程与工业空气动力学专业委员会委员。主要从事大气边界层物理、城市气象、低空气象等方向的研究。先后承担和参加国家自然科学基金项目、“气象联合基金”项目、973项目、国家重点研究计划课题10余项，发表相关学术论文90余篇。主持开发的城市过程参数化方案和基础数据库受到广泛关注和应用，先后获教育部高校优秀科研成果奖自然科学奖二等奖等多次学术奖励。

Past Events #10

Understanding the impacts of urban form and function on the lower atmosphere

Qi Li (Cornell University) : 15th Mar 2025, Saturday

Abstract:

The physical state variables in the lower atmosphere such as hydrometeorological quantities are determined by the universal first-principle physical laws governing land-atmosphere interactions. However, city-specific boundary conditions represented by the urban form and function often complicate our understanding and prediction of the physical state of the lower atmosphere. In the first part of the talk, we discuss how high-resolution large-eddy simulation modeling improves our understanding of the impact of urban form on urban hydroclimates. In the second part of the talk, we discuss the impact of urban function by focusing on the quantification of anthropogenic heat emissions. We demonstrate how a combination of observations and state estimation method could potentially improve the spatiotemporal estimation of anthropogenic heat.

Biograph:

Dr. Qi Li is an associate professor in the School of Civil and Environmental Engineering at Cornell University. She completed her Ph.D. in Civil and Environmental Engineering at Princeton University in 2016. Her research focuses on developing and applying computational models to improve the understanding of turbulent flows and transport of scalars in the lower atmosphere, especially over complex surfaces, such as the urban environment. She is the recipient of the NSF CAREER award in 2022.

Past Events #9

New Perspectives on Urban Climate Research from Refined Data and Modelling

Jiachuan Yang (The Hong Kong University of Science and Technology): 11th Jan 2025, Saturday

Abstract:

Sincethe first review of urban climatology by Oke in 1970s, urban climate research has gained increasing attention and made substantial progress over the five decades. Benefitting from the development of sensors and advances in computational technology, refined data and modelling allows urban climate to be studied at an unprecedented resolution. This talk will give examples of how latest observational data and new modelling approaches provide insights into the state of knowledge about urban climate at various temporal and spatial scales. As a key component among new modelling approaches, the potential of machine learning models for predicting urban climateis reviewed and discussed.

Biograph:

Dr. Jiachuan Yang is an Associate Professor in the Department of Civil and Environmental Engineering at the Hong Kong University of Science and Technology. His research focuses on urban microclimate, hydrometeorological modelling, land-atmosphere interaction and turbulence. The ultimate goal is to advance the fundamental understanding of the urban environment and promote its multisector sustainability. He has published more than 50 peer-reviewed journal papers. And his contribution has been acknowledged by the Yuxiang Young Scholar Award by the Chinese American Oceanic and Atmospheric Association, and the Excellent Young Scientists Fund (Hong Kong & Macau) by the National Natural Science Foundation of China.

Past Events #8

Quantifying the regional climate and environmental effects of urbanization and the potential of rooftop strategies

Xuemei Wang (JINAN UNIVERSITY): 14th Sep 2024, Saturday

Abstract:

Urban expansion modifies the atmosphere through surface property changes and anthropogenic emissions. This study refines the parameters of urban canopy models, integrating numerical experiments with observational data to assess the climate and environmental impacts of urbanization in the Pearl River Delta (PRD) urban agglomeration and the high-altitude city of Lhasa, both historically and projected into the future. A refined inventory of regional anthropogenic heat emissions was developed and incorporated into numerical simulations. Hence the influence of anthropogenic heat on the intensity of urban heat islands was quantified. Additionally, the study examined the effects of urbanization on precipitation patterns in the PRD region, suggesting a potential rise in convective extreme rainfalls in the central and downwind regions of urban agglomerations, attributed to adjustments in urban thermodynamics.

Urban rooftops are recognized as valuable resources for implementing strategies to mitigate climate change. In this study, we conducted rooftop observational experiments to quantify the cooling effects of cool (reflective) roofs and roofs with various vegetation types. Based on these experimental observations, we refined the parameterization scheme for green roofs to create a mixed-vegetation roof scheme. Through an extensive literature review, we modified the parameterization scheme for rooftop photovoltaics and developed schemes that integrate bifacial photovoltaics with cool and green roofs. We then quantified the impact of these various roof strategies on the roof surface energy balance and their cooling effects using numerical modeling. Finally, we assessed the power generation capacity, carbon reduction potential, and economic feasibility of rooftop photovoltaics in the PRD urban agglomeration.

Biograph:

Prof. Xuemei Wang is a distinguished scholar who has been honored with several prestigious awards, including the National Science Foundation for Distinguished Youth Scholars of China, Chief Scientist of the Key R&D Program of the Ministry of Science and Technology, and Special Allowance Expert of the State Council. She has dedicated her research to understanding the impact of key processes in land-atmosphere exchange on regional climate and atmospheric environment, as well as improving air quality models through parametric development. Her multi-layer canopy model has been widely adopted by 10 atmospheric chemistry models worldwide, including CMAQ and WRF-Chem, and has been implemented by over 500 academic institutions across 50 countries. Professor Wang’s research provides valuable scientific support for major events such as the Guangzhou Asian Games and collaborative prevention and control of air pollution in the Pearl River Delta region.

To date, Prof. Wang has led more than ten national and international cooperation projects, and published more than 200 papers. She holds a position on the scientific committees of both the International Commission on Atmospheric Chemistry and Global Pollution (iCACGP) and the Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPs). Additionally, she has served as a reviewer for the 5th Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) and is a member of the editorial board for several prestigious SCI journals focused on atmospheric environments, including Advances in Atmospheric Sciences, Urban Climate, Aerosol and Air Quality Research, Atmospheric Environment, and Asia-Pacific Journal of Atmospheric Sciences.

Past Events #7 (record)

Investigations of sustainable urban wind and thermal environments based on high-resolutionfield measurements and multi-scale numerical simulations

Jian Hang (SUN YAT-SEN UNIVERSITY): 27th Jul 2024, Saturday

Abstract:

Some innovative researches have been conducted with regards to the influence of urban morphology and urban vegetation on urban climate and environmental quality, which provides effective methodologies for sustainable urban climate design and prediction.

First, high-quality parametric outdoor experimental data of urban climate is relatively rare. Novel scaled outdoor urban models were created in subtropical climate regions. These models are flexible in controlling building parameters and vegetation arrangements, and can easily measure heat storage fluxes. Parametric scaled outdoor measurements of urban climate were performed to quantify the spatial and temporal characteristics of urban turbulence, wind and thermal environment as well as urban energy balance, which is conducted for the first time in China with special patterns worldwide. Second, such high-quality scaled experimental data are adopted to provide validation for numerical simulations and urban canopy models, producing better numerical estimation accuracy. The multi-scale numerical simulations by coupling meso-scale model (WRF) and computational fluid dynamics (CFD) are also developed to provide numerical prediction of urban climate for Xiongan New area. Finally, some new urban ventilation concepts and exposure/thermal comfort index are used to assess and quantify the dynamic and thermal influencing mechanisms of meteorological conditions, urban morphology, vegetation parameters, etc., on urban turbulent ventilation and pollutant exposure as well as outdoor thermal comfort.

These researches are supported by five research projects of National Natural Science Foundation of China (NSFC) including National Natural Science Foundation--Outstanding Youth Foundation in 2016, three general NSFC projects and one international cooperation NSFC project.

Biograph:

Prof Hang was born in 1980. He got the PhD degree in the University of Hong Kong(HKU) in 2009 and worked as a postdoc in HKU from 2009-2012. Then he entered Sun Yat-sen University as an associate professor in 2012 and became a professor in 2018. His major research topic is urban climate science, i.e. based on high-resolution field measurements (wind tunnel experiments, some new-type scaled outdoor measurements, outdoor field experiments in real cities) and multi-scale numerical simulations(street-scale CFD, meso-scale, multi-scale simulations etc), he emphasized and investigated the influencing mechanisms of urban wind/thermal environment by urban morphologies, vegetations and cool coating etc. The topic includes urban turbulence, urban ventilation and pollutant dispersion as well as urban thermal environment (or urban heat island effects) and urban energy balance. By 2024, he has led 6 research projects of the National Natural Science Foundation of China (NSFC), including National Natural Science Foundation--Outstanding Youth Foundation in 2016 and three general NSFC projects. A total of 128 SCI papers were published with six ESI highly-cited SCI papers. Among them, the applicant acting as the first or corresponding author for 75 SCI papers and 65 journal papers of them were published in JCR first-level SCI journals or journals with impact factor IF>5. The applicant became the member in the list of World's Top 2% Scientists 2023.

Past Events #6 (record)

Demand-driven developments of urban meteorological multi-scale model system

Shiguang Miao (Institute of Urban Meteorology, CMA, Beijing): 15th Jun 2024, Saturday

Abstract:

In recent years, urbanization has developed rapidly, and urban meteorological and environmental issues have become increasingly prominent. In response to the growing demands for refined urban meteorological services, researches have been conducted at kilometer scale, hundred-meter scale, and microscale, and a multi-scale urban meteorological model system (RMAPS) has been developed. 1) On kilometer scale: based on the observation data of high-density automatic meteorological stations in Beijing, the impacts of urbanization on meteorological elements, especially the relationship between urban heat island effects and urban precipitation, are investigated; In response to the demand for fine-scale urban meteorological forecasting and services, the urban canopy model is developed and coupled with regional numerical weather prediction model (RMAPS-ST); The impacts of urban underlying surfaces and aerosols on precipitation are studied; 2) On hundred-meter scale: RMAPS-LES has been developed to meet the meteorological service needs of Winter Olympics; 3) On microscale: an Urban Rapid Building-Aware Neighborhood model(URBAN) has been developed to meet the demand for meteorological services for major events. The RMAPS model system provides important technological support for the management and safe operation of modern cities, as well as meteorological support for major national events such as the Beijing Winter Olympics. Finally, related research plans in WMO and the Key Laboratory of Urban Meteorology, China Meteorological Administration, new demands and future directions in urban hundred-meter scale research and the meteorological support for low-altitude economy will be discussed.

Biograph:

Shiguang Miao is a senior scientist and director of the Institute of Urban Meteorology (IUM), China Meteorological Administration (CMA), in Beijing, which is dedicated to urban research and operational numerical (chemical) weather forecast for Beijing. He received his Ph. D in Atmospheric Sciences at Nanjing University in 2003. He is the chair of the committee for urban meteorology of the Chinese Meteorological Society (2016-), and member of the Board on the Urban Environment of the American Meteorological Society (2016-2019), and member of WMO WWRP SSC (2020-). His research interests include observational analysis and numerical modeling of urban land surface and boundary layer, and urbanization impacts on high-impact weather.

Past Events #5 (record)

A Personal Journey Through the Urban Weather and Climate Research

Fei Chen (The Hong Kong University of Science and Technology): 27th Apr 2024, Saturday.

Abstract:

This presentation offers a personal reflection on my journey through urban weather and climate research. It all began in 2002 when I was involved in a project to support the Joint Urban 2003 Field Project in Oklahoma City. During this project, I developed a simple bulk city-parameterization scheme for the MM5 model, which was the prevailing mesoscale modeling tool before the advent of WRF. The refined MM5 was successfully employed in the Joint Urban fieldwork, yielding intriguing simulation results that posed unanswered questions. These unresolved inquiries, together with other pioneering research in urban weather, inspired my exploration into various scientific and modeling aspects pertinent to urban weather and air quality investigations. This trajectory of collaborative research endeavors culminated in an international effort in developing the integrated WRF-Urban modeling system. Additionally, my focus extended to understanding urban regional circulation, precipitation mechanisms, and extreme weather and climate events. I'll touch on people inspiring me, lessons learned from those collaborative endeavors, and future work in urban modeling. More recently, I am involved in the World Climate Research Programme's My Climate Risk (MCR) initiative and promote the establishment of MCR Regional Urban Hubs. These regional hubs serve as crucial platforms for addressing urban climate risks tailored to the specific challenges faced by different regions.

Biograph:

Fei Chen is currently a professor within the Division of Environment and Sustainability at the Hong Kong University of Science and Technology. Prior to this role, he spent over 26 years at the National Center for Atmospheric Research and led projects to develop the community Noah and Noah-MP land/hydrology models, and the WRF-Urban and WRF-Crop coupled models. His research interests and expertise include understanding land-atmosphere interactions and their impacts on boundary layer structures and precipitation. He also investigates the feedback mechanisms between soil moisture, vegetation conditions, land-use and land-cover changes, urbanization, agriculture management, and regional hydroclimate. His research extends to urban heat islands and their mitigation strategies, and urban extreme weather and climate. He chaired the American Meteorological Society (AMS) Award Nomination Committee and the Board on the Urban Environment. He was an Elected Board Member of the International Association for Urban Climate (IAUC) Board. He was elected to a Fellow of the AMS in 2013 and received the 2018 Helmut E. Landsberg Award from the AMS.

Past Events #4 (record)

From applied Meteorology to Climate Science: A White Roof Example

Dan Li (Boston University): 9 p.m., Beijing time (GMT+8), 9th Mar 2024, Saturday.

Abstract:

As the urban population continues to rise and the climate continues to warm, the importance of urban climate within the realm of urban science is undisputed. Urban climate sits at the intersection of applied meteorology and climate science. The field of urban climate thrives when it integrates and balances insights from both applied meteorology and climate science. However, studies in urban climate predominantly adopt a perspective of applied meteorology. One case in point is the evaluation of white roofs as a strategy for mitigating heat. In this presentation, I will demonstrate how shifting our focus from applied meteorology to climate science can enrich our understanding of this urban adaptation challenge. Key concepts such as climate forcing, climate feedback, and climate sensitivity will be discussed.

Biograph:

Dr. Dan Li is an Associate Professor in the Department of Earth and Environment and Department of Mechanical Engineering at Boston University. He completed his Ph.D. in 2013 in the Department of Civil and Environmental Engineering at Princeton University. Prior to joining Boston University in 2016, he was a postdoctoral research associate in the Program of Atmospheric and Oceanic Sciences at Princeton University. His research focuses on improving the understanding of the dynamics and thermodynamics of the atmospheric boundary layer and applying the knowledge to addressing real world sustainability challenges. He is the recipient of the Humboldt Fellowship for Experienced Researchers from the Alexander von Humboldt Foundation, the 2022 Timothy Oke Award from the International Association for Urban Climate, and the 2023 American Geophysical Union Global Environmental Change Early Career Award.

Past Events #3

Creating breathing cities by adopting urban ventilation assessment and wind corridor plan – The implementation in Chinese cities

Chao Ren (University of Hong Kong):27th Jan 2024, Saturday.

Abstract:

In recent years, urban ventilation assessment and urban ventilation corridor plan have been conducted and adopted in the urban planning of Chinese cities in response to the national call from the Central Government of China as well as the public concern on the quality of living environment. Therefore, a national technical guide is needed to provide a state-of-the-art standard methodology and scientific technology on urban ventilation assessment, and to serve as an aid for decision-making in the initial stage of town planning and urban design. This presentation first reviews the urban ventilation corridor plan related activities in Chinese cities since 2000 and points out the needs and problems. Secondly, it introduces the newly developed national technical guide 'Specifications for climatic feasibility demonstration – Urban Ventilation Corridor'. Thirdly, a case study of Chengdu Urban Ventilation Corridor Plan is presented to demonstrate the implementation of such considerations in local planning exercises. Lastly, it discusses the future trend of urban ventilation assessment and urban ventilation corridor plan in China.

Biograph:

Dr. Chao REN is an Associate Professor in the Faculty of Architecture at the University of Hong Kong. She specializes in applied climatology and climate design, who uses GIS, and spatial modelling methods and remote sensing techniques to study urban environmental performance and develop climate response design strategies and guidelines. Chao is a Co-Editor-in-Chief for Urban Climate and a member of the Urban Climate Expert Team and the Study Group on Greenhouse Gas Monitoring of the World Meteorology Organization. She has also been elected as a Board Member of the International Association for Urban Climate (2017-2021). She has been involved in several international collaborative research reports, including the IPCC AR6 and the China report of the Lancet Countdown on Health and Climate Change.

Past Events #2 (record)

Understanding urban heat in a changing climate at large scales

Lei Zhao (University of Illinois Urbana-Champaign): 18th Nov 2023, Saturday.

Abstract:

Cities are where major human-perceived climate change impacts occur. The uniqueness of local urban climates such as urban heat island, a common phenomenon of relative urban warmth compared to surrounding rural areas, further exacerbates the heat stress induced by non-local greenhouse gas-induced warming. The associated socioeconomic impacts (such as public health, energy, and workplace productivity) are often much higher in urban areas than over other landscapes due to the concentrated population, infrastructure, and assets. These hazardous risks are projected to be further worsened due to rapid urbanization coupled with climate change. Understanding the mechanism of urban heat, its interaction with climate change, and the associated impacts is essential for effective urban climate adaptation and resilient development. Here in this seminar, I will first present some of our recent works that combine Earth system modeling, theory, physics-informed machine learning, and remote sensing to understand urban heat, future urban climate change, variability and uncertainty, humid heat stress, exposure, and its implication to heat adaptation, and urban climate-energy interactions at large scales. In the second part, I will present some recent advances in representing urban-scale processes and dynamics in global-scale Earth system models.

Biograph:

Lei Zhao is an assistant professor in the Department of Civil and Environmental Engineering, Institute for Sustainability, Energy, and Environment (iSEE), and the National Center of Supercomputing Applications at the University of Illinois Urbana-Champaign (UIUC). His research concerns the physical and engineering processes in the atmospheric boundary layer where most human activities and environmental systems are concentrated, with a particular focus on built surfaces and urban environments. He combines theory, numerical modeling, remote sensing and in situ observations, and cutting-edge machine learning methods to study land-atmosphere interaction and environmental fluid mechanics that relate to urban climatology and hydrology, urban climate change, impacts, and adaptation. Lei is the recipient of the U.S. NSF CAREER Award, the Timothy Oke Award (2023) from the International Association for Urban Climate, and the American Geophysical Union (AGU) Global Environmental Change Early Career Award (2023). He received his Ph.D. degree in atmospheric physics from Yale University and B.S. degree from Nanjing University. Before joining at UIUC, he worked as a postdoctoral fellow at Princeton University.

Past Events #1 (record)

A new paradigm of urban climate modeling: from complex processes to complex

Zhihua Wang (Arizona State University): 28th Oct 2023, Saturday.

Abstract:

The growth of civilization, from a historical perspective, proceeds by a recurrent rhythm of successful responses to continuous challenges, as a potentially infinite élan vital. Environmental challenges faced by cities worldwide include the excessive thermal stress, concentrated greenhouse gas emissions, degraded ecosystem services, and risks to human health and infrastructure resilience, to name a few. Past decades have seen drastically increasing efforts devoted to the development and enhancement of realistic urban climate models that can capture complex urban land-atmosphere interactions. These models have been tested and evaluated to find more sustainable solutions to counteract the urban environmental challenges, with success at difference degrees and scales. Moreover, rich databases generated by urban climate modeling, field measurements, and reanalysis, enable us to move forward from the current paradigm of process-based urban climate modeling towards more holistic system-based techniques and frameworks. In this seminar, we present a novel urban climate modeling framework by treating cities as inter-connected dynamic systems, running on top of the substrate of heterogeneous topology that entail intricate human-environment interplays. More specifically, we will discuss some recent advances along the line, including analysis of complex urban climate networks, predicting critical transition in urban climate systems, quantifying causal graphs for extreme urban heatwaves, and machine learning based techniques.

Biograph:

Dr. Zhihua Wang is an associate professor in the School of Sustainable Engineering and the Built Environment at Arizona State University. He obtained B.Eng and M.Eng degrees from the School of Civil and Environmental Engineering at Nanyang Technological University, Singapore, in 2002 and 2004 respectively, and Ph.D. from Princeton University in 2011. Dr. Wang's primary research interest focuses on the sustainable development of urban environments, including urban land-atmosphere interactions, heat mitigation strategies, environmental quality, and complex urban system modeling.