Article
Multidisciplinary Sciences
Liang Qiao, Zhiyan Zuo, Renhe Zhang, Shilong Piao, Dong Xiao, Kaiwen Zhang
Summary: Soil moisture-atmosphere coupling induces non-linear warming via the 'warmer climate - drier soil' feedback, exerting an accelerating effect on global warming and extreme high temperatures. The projection shows that SA-driven warming will exceed 0.5°C over extratropical landmasses by the end of the 21st Century, increasing the likelihood of extreme high temperatures.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Gao-Lin Wu, Zhen Cheng, Juha Mikael Alatalo, Jingxue Zhao, Yu Liu
Summary: This study found that aboveground net primary productivity (ANPP) of all major grassland types in northern China consistently declined over the past 30 years, on average by about 6.1%. The primary factor driving this decrease was warming, increased solar radiation, and resulting soil temperature rise. Alpine and lowland grasslands were more sensitive to climate change compared to temperate grasslands.
Article
Agronomy
Zhenxing Zhou, Kunpeng Zhang, Zhaolin Sun, Yinzhan Liu, Yuanchen Zhang, Lingjie Lei, Ying Li, Dong Wang, Mengjun Hu, Shilin Wang, Quanwei Lu, Yupeng Cui, Mingxing Zhong, Shijie Han, Yuan Miao
Summary: Experimental warming was shown to extend the flowering season by approximately 2.08% across all species, with varying responses based on plant functional types such as herbaceous and woody species. The impacts of warming on different pollination types, latitude, and temperature showed contrasting results, highlighting the complexity of how climate warming affects terrestrial plant phenology.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Environmental Sciences
Feng Ye, Satoshi Kameyama
Summary: The study found that the majority of monitoring sites in Japan are experiencing increasing freshwater temperatures, which may have adverse impacts on aquatic ecosystems. However, some sites showed decreasing trends in freshwater temperature. The temperature change rate suggests that the warming of freshwater is not solely due to atmospheric warming.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Siyi Wang, Yongli He, Shujuan Hu, Fei Ji, Bin Wang, Xiaodan Guan, Sebastiano Piccolroaz
Summary: Lake surface water temperature is highly sensitive to climate change and is found to be warming globally. The warming rate of global lakes varies by region, with dryland lakes experiencing more significant warming compared to semi-humid and humid regions. Air temperature is identified as the main driving force for lake warming. Future projections indicate that lake surface water temperature will continue to rise, especially in dryland areas.
Article
Construction & Building Technology
Shuo-Jun Mei, Chao Yuan
Summary: This study investigates the transient street air warming process caused by anthropogenic heat using an analytical model and Large-Eddy Simulation (LES), showing that the introduction of buoyancy effect in the model leads to more accurate results. Buoyancy plays a significant role in influencing exchange velocity and urban canopy flow structure.
ENERGY AND BUILDINGS
(2021)
Article
Geosciences, Multidisciplinary
Zhenxin Liu, Yuanhao Chen, Yuhang Wang, Cheng Liu, Shuhua Liu, Hong Liao
Summary: The heterogeneity of urban canopy leads to the spatial inhomogeneity of wind field in urban street canyons. Most current urban canopy models do not consider this heterogeneity, resulting in large discrepancies between simulated and observed wind speeds. In this study, a parameterization scheme called IWSUS is developed to better characterize the heterogeneity of the urban canopy. Validation results show that IWSUS performs better than the widely used exp-log law.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
Article
Geosciences, Multidisciplinary
Zhiyan Zuo, Dong Xiao, Qiong He
Summary: The study analyzed the role of long-term warming trends in global land SAT variations and found that less than one-third of annual SAT variations were contributed by the warming trend in most regions. In certain areas such as eastern South America, parts of South Africa, southwestern Mediterranean, and Sunda islands, where the absolute warming rate was moderate, but a high ratio of warming trend to SAT variations indicated significant loss of habitat for endemic species. Therefore, the ratio of warming trend to SAT variations may be a better measure compared to the absolute warming rate for assessing local ecoclimatic effects.
SCIENCE CHINA-EARTH SCIENCES
(2021)
Review
Environmental Sciences
Yuhan Huang, Chengwang Lei, Chun-Ho Liu, Pascal Perez, Hugh Forehead, Shaofei Kong, John L. Zhou
Summary: This paper reviews the mechanisms controlling vehicle emission dispersion in urban street canyons and the strategies for managing roadside air pollution. Key factors influencing air pollution in street canyons include traffic conditions, canyon geometry, weather conditions, and chemical reactions. Mitigation strategies include traffic interventions and city planning, with the latter having a more significant impact on pollutant dispersion.
ENVIRONMENTAL POLLUTION
(2021)
Article
Engineering, Environmental
Meng Qi, Steve Hankey
Summary: By leveraging Google Street View imagery and deep learning models, we developed LUR models for predicting street-level particulate air pollution, achieving higher spatial resolution and better performance compared to traditional LUR models.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Jun Qin, Min He, Wei Yang, Ning Lu, Ling Yao, Hou Jiang, Jin Wu, Kun Yang, Chenghu Zhou
Summary: The Tibetan Plateau is experiencing rapid warming, leading to increased glacial melting and natural hazards. However, due to a lack of high-quality, long-term observations, there is no complete understanding of its temperature status in the past few decades. This study uses satellite and weather station data to derive long-term surface air temperatures, revealing widespread warming across the plateau, particularly in the western region. The derived warming rate is higher than other datasets, implying a severe threat to the cryosphere.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Jun Qin, Min He, Hou Jiang, Ning Lu
Summary: The warming amplification of the Tibetan Plateau has had significant impacts on the environment in the region. However, the current understanding of temperature change on the plateau is still inadequate due to deficiencies in data sources. Therefore, a multi-source data fusion method is proposed to integrate different data and generate a comprehensive temperature dataset for the Tibetan Plateau.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Tien-Yiao Hsu, Gudrun Magnusdottir, Francois Primeau
Summary: We conducted quadrupled CO2 climate simulations using CESM1 to investigate the impact of air-sea coupling on the response of tropical rainfall under global warming. By employing a range of ocean models, we were able to identify the specific contributions of seasonal mixed-layer entrainment, wind-driven Ekman flows, and near-equator frictional flows. Our findings demonstrate that the enhanced equatorial warming pattern and the contraction of the intertropical convergence zone in the Pacific Ocean, observed in previous climate simulations, only emerge when the ocean model includes wind-driven Ekman and frictional flows. Additionally, we discovered that the near-equator frictional flow accounts for more than half of the heat convergence in the equatorial Pacific Ocean. Moreover, the interactions between the Ekman flow, near-equator frictional flow, and the Hadley circulation result in opposite feedbacks on the strength of the enhanced equatorial warming pattern.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geography, Physical
Lu Gao, Haijun Deng, Xiangyong Lei, Jianhui Wei, Yaning Chen, Zhongqin Li, Miaomiao Ma, Xingwei Chen, Ying Chen, Meibing Liu, Jianyun Gao
Summary: Despite widespread controversy over the existence of elevation-dependent warming, significant EDW signals were detected in the Chinese Tian Shan, especially at different altitudes and on different timescales.
Article
Environmental Sciences
Guojie Hu, Lin Zhao, Tonghua Wu, Xiaodong Wu, Hotaek Park, Ren Li, Xiaofan Zhu, Jie Ni, Defu Zou, Junming Hao, Wangping Li
Summary: This study evaluates the air temperature trends in the permafrost region of the Northern Hemisphere (PRONH) using CMIP6 models and observational data. The results show that there are variations in air temperature trends among different permafrost regions, and the greatest warming trends are observed in high-latitude permafrost regions under future scenarios.
Article
Meteorology & Atmospheric Sciences
P. W. Chan, W. Kong, J. Wurman, K. Kosiba, P. Robinson, Tang Zhan, Chan Wa Lok, Q. S. Li
Summary: A waterspout occurred in Macao on 1 June 2021, as provided by the radio station of Macao.
Editorial Material
Meteorology & Atmospheric Sciences
P. W. Chan, K. K. Hon
Summary: This article discusses three cases of sea breezes observed at Hong Kong International Airport and provides results from numerical simulations, including wavy structures, vortices, and large changes in temperature and humidity associated with the sea breeze.
Article
Engineering, Civil
T. Chen, J. Y. Fu, P. W. Chan, Y. C. He, A. M. Liu, W. Zhou
Summary: This paper explores the use of Lidar wind profilers to measure typhoon wind characteristics, focusing on the mean and fluctuating components. Wind field measurements were successfully captured during the passage of two typhoons, and a wind spectrum model was proposed to correct the wind turbulence parameters. The results provide valuable insights into the wind characteristics of the typhoon boundary layer and contribute to the development of using Lidar profiler for observing wind turbulence.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2023)
Article
Environmental Sciences
Afaq Khattak, Pak-Wai Chan, Feng Chen, Haorong Peng
Summary: Severe low-level wind shear (S-LLWS) near airport runways is a safety concern for civil aviation. This study introduces the SPE framework and SHAP interpretation system for the prediction and interpretation of LLWS severity. The SPE framework outperforms tree-based models in terms of prediction performance.
Article
Environmental Sciences
Afaq Khattak, Pak-Wai Chan, Feng Chen, Haorong Peng
Summary: Machine learning algorithms were used to predict intense wind shear at Hong Kong International Airport using Doppler LiDAR data. Accurate forecasting of intense wind shear near airport runways is crucial for intelligent management and timely flight operations. Bayesian-optimized machine learning models, including adaptive boosting, light gradient boosting machine, categorical boosting, extreme gradient boosting, random forest, and natural gradient boosting, were developed to predict the time series of intense wind shear. Among the models tested, the Bayesian optimized-Extreme Gradient Boosting (XGBoost) model outperformed others with the lowest mean absolute error (1.764), mean squared error (5.611), root mean squared error (2.368), and highest R-Square (0.859). The XGBoost model was further interpreted using the SHapley Additive exPlanations (SHAP) method, which revealed that the month of the year and the location of the most intense wind shear were the most influential features. August exhibited a higher likelihood of experiencing intense wind shear, and most of these events occurred on or near the runway's departure end within one nautical mile.
Article
Environmental Sciences
Lei Li, Qian-Jin Zhou, Pak-Wai Chan, Hong-Long Yang
Summary: Most studies analyzing the effects of urbanisation on local climate have relied on ground observation data, but our study used observation data from a radar wind profiler, radio-acoustic sounding system, and automatic meteorological station to investigate changes in wind and virtual temperature in the upper atmosphere over the Pearl River Estuary. Our results showed significant and rapid changes in both wind speed and virtual temperature at the upper level atmosphere compared to the changes observed at ground level. The increase in virtual temperature in the upper atmosphere was found to be higher than that on the land surface, and the mean decreases in wind speeds were higher at the upper level atmosphere.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Yangzhao Gong, Zhizhao Liu, Pak Wai Chan, Kai Kwong Hon
Summary: In this study, the impact of assimilation of GNSS PWV and radio-sonde profiles on the performance of the WRF model in forecasting PWV and rainfall over the South China region was investigated. Five different WRF schemes were adopted, and it was found that all DA schemes improved the WRF forecasting performance for both PWV and rainfall. Among these schemes, WRF scheme 4 showed the best performance.
ATMOSPHERIC RESEARCH
(2023)
Article
Environmental Sciences
Zibo Zhuang, Hui Zhang, Pak-Wai Chan, Hongda Tai, Zheng Deng
Summary: In this study, a flight turbulence identification model using a conditional generative adversarial network (CGAN) and extreme gradient boosting (XGBoost) is proposed. The model effectively addresses the imbalanced proportions of the data category samples in the LiDAR turbulence identification model, improving recognition accuracy and robustness.
Article
Environmental Sciences
Chong Shen, Yiming Liu, Wei Dai, Xiaoyang Chen, Qi Fan, Xuemei Wang, Pakwai Chan, Chunlin Wang, Weijuan Pan, Jieyi Li, Xiaohui Li, Jie Wu
Summary: This study implemented localised and non-uniform urban morphology and urban fraction parameters in a single-layer urban canopy scheme in the WRF model, and evaluated the effect on the simulation of dynamic and thermal fields in the urban canopy of Guangzhou. The results showed that using localised UM parameters significantly improved the simulation of 10 m wind speed, and higher UF and UM values resulted in higher surface temperatures and increased ground heat flux in the urban canopy.
Article
Environmental Sciences
Cailing Li, Haobo Tan, Guorong Wang, Pakwai Chan, Jincan Huang, Yun Luo
Summary: An array weather radar (AWR) network with seven X-band phased-array radars was built in Foshan, Guangdong Province, China. The radar system has high spatial and temporal resolutions, allowing for the detection and analysis of convective storms such as hail, thunderstorms, strong winds, and heavy precipitation. The results show that the phased-array radars can accurately detect the evolution process of storms, providing valuable information for predicting future trends. The three-dimensional wind field analysis provides insights into the dynamic mechanisms of storm strengthening and weakening, enabling advanced warning for severe weather events.
Article
Geochemistry & Geophysics
Enoch Yan Lok Tsui, Pak Wai Chan, Ralf Toumi
Summary: The vertical wind structure of translating tropical cyclones, including asymmetric inflow angles, has been studied through dropsonde data primarily from strong cyclones in the Atlantic. This study focuses on weak landfalling cyclones near Hong Kong and finds that decaying tropical storms exhibit larger mid- to low-level inflow angles compared to intensifying or steady-state storms. The inflow angles converge near the top of the boundary layer for intensifying, steady-state, and decaying tropical storms. Decreasing wind speed across the boundary layer is observed in all three cases. The stronger inflow in decaying storms is attributed to enhanced surface friction over land during weakening stages.
ATMOSPHERIC SCIENCE LETTERS
(2023)
Article
Construction & Building Technology
Afaq Khattak, Pak-wai Chan, Feng Chen, Haorong Peng
Summary: In this study, a scaled-down model of Hong Kong International Airport and its surrounding terrain were built in a wind tunnel to investigate wind turbulence intensity. Machine learning algorithms were used to predict turbulence intensity, and the results showed that terrain, distance from the runway, and wind direction significantly contributed to high turbulence intensity along the glide path. The most favorable conditions for high turbulence intensity were the presence of complex terrain, a shorter distance from the runway, and an inflow wind direction between 125 and 200 degrees.
BUILDING AND ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
Afaq Khattak, Pak-wai Chan, Feng Chen, Haorong Peng
Summary: In this study, the Explainable Boosting Machine (EBM) model was used to estimate the variation in headwind speed and turbulence intensity along the airport runway glide slope and interpret the contributing factors. The EBM model showed superior performance compared to other black box and glass box models. It allowed for a full interpretation of the contribution of different factors to the prediction results and evaluation of their impact on wind field characteristics.
SCIENTIFIC REPORTS
(2023)
Article
Environmental Sciences
Yueyang He, Zixuan Wang, Hau Man Wong, Guangzhao Chen, Chao Ren, Ming Luo, Yuguo Li, Tsz-cheung Lee, Pak Wai Chan, Janice Ying-en Ho, Edward Ng
Summary: In humid subtropical regions like Hong Kong, rising temperatures have led to an increase in compound temperature-humidity extreme events. This study reveals the spatial-temporal changes of these events in Hong Kong from 1961 to 2020, identifying four types of compound events. The study finds that there has been an increase in hot and wet events and a decrease in cold and dry events. Additionally, built-up areas experience more frequent compound events compared to rural areas.
Article
Multidisciplinary Sciences
Jia-Chen Su, Lei Li, Pak Wai Chan, Qian -Jin Zhou, Hong -Long Yang
Summary: Based on the simulation of the fluid-structure interaction response, this paper studies the cause of a gantry crane overturning induced by a downburst in Shenzhen. The results show that: (1) Vicroy's downburst model can more reasonably establish the steady-state wind field of the downburst when there is only low-level wind speed observation data, and its simulation results are close to the two-dimensional downburst numerical simulation results; (2) Compared with the normal exponential vertical profile of wind speed, the disturbance caused by the front girder of the double-girder gantry crane structure under the downburst wind field is more severe, increasing the probability of gantry crane overturning; (3) The downwind displacement of the gantry crane's main girder under the downburst condition is far greater than that under normal conditions. At the same time, under the downburst condition, the pressure difference on the surface of the gantry crane is greater, and the distribution of the support reaction force is more uneven, resulting in a stronger overturning tendency of the gantry crane; (4) Under the downburst condition, the overturning moment and shearing force borne by the foundation of the gantry crane exceed the critical value to maintain the stability of the gantry crane by gravity, resulting in the overturning of the gantry crane.