Article
Meteorology & Atmospheric Sciences
Yue Qin, Weilin Liao, Dan LI
Summary: The study improves the Two-Resistance Mechanism (TRM) attribution method to analyze the urban-rural contrast of heat stress. The method can diagnose any heat stress index related to temperature and humidity. The summertime urban-rural contrast of Simplified Wet Bulb Globe Temperature (SWBGT) is primarily caused by evapotranspiration and heat storage release in urban areas. The differences in aerodynamic features in urban-rural areas play both positive and negative roles.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Talha Hassan, Jiahua Zhang, Foyez Ahmed Prodhan, Til Prasad Pangali Sharma, Barjeece Bashir
Summary: This study examines the phenomena of surface urban heat islands (SUHI) in seven megacities of South Asian countries over a period of 20 years. The results show a decrease in vegetated areas and varying trends in urban heat island intensity (SUHII) in different cities. Additionally, poor ecological conditions were observed in urban buffers due to high land surface temperature (LST) and urban infrastructures, with a strong negative correlation between LST and normal difference vegetation index (NDVI).
Article
Meteorology & Atmospheric Sciences
Jun Ge, Bo Qiu, Bowen Chu, Duzitian Li, Lingling Jiang, Weidan Zhou, Jianping Tang, Weidong Guo
Summary: This study evaluates the performance of three regional climate models in representing the local biophysical effects of afforestation over continental China. The models do a poor job in describing afforestation-induced changes in surface biophysical properties such as albedo and leaf area index, as well as changes in latent and sensible heat fluxes. However, they are generally reasonable in representing the impact of afforestation on temperature.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Dashan Wang, Xianwei Wang, Lin Liu, Dagang Wang, Zhenzhong Zeng
Summary: This study quantitatively examines the spatial clustering of precipitation intensity in 130 urban-affected regions over mainland China during 2008-15. The results show that the spatial heterogeneity patterns display diverse distribution and vary with precipitation intensity and urban sizes. Urban signatures in the spatial clustering of precipitation extremes are observed in 28% of cities, mainly occurring in the Haihe River basin, the Yangtze River basin, and the Pearl River basin.
JOURNAL OF HYDROMETEOROLOGY
(2021)
Article
Environmental Sciences
Marco Morabito, Alfonso Crisci, Giulia Guerri, Alessandro Messeri, Luca Congedo, Michele Munafo
Summary: This study investigated the summer daytime surface urban heat island phenomenon in 10 Italian peninsular metropolitan cities, finding that impervious and tree cover surfaces play a key role. The most intense heat island effects were observed in inland cities, with a mitigating effect of the sea on coastal cities.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Chi Chen, Dan Li, Trevor F. Keenan
Summary: Satellite observations show that the surface urban heat island intensity (SUHII) has been increasing over the last two decades, accompanied by an increased urban-rural contrast of vegetation greenness. The study uses a data-model fusion approach to quantify the contribution of uneven vegetation trends in urban and rural areas to the trend of SUHII during the peak growing season. Increasing trend of LAI(dif) accounts for about one quarter of the trend in satellite-derived SUHII, particularly in rapidly urbanizing and intensively cultivated rural areas. Urban greening trends play a crucial role in modulating urban-rural temperature differences.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Liang Wang, Dan Li
Summary: The study finds that during the day, Boston exhibits a surface urban heat island (SUHI) due to higher urban surface resistance, while Phoenix shows a surface urban cool island because of lower urban aerodynamic resistance. At night, Boston has both a SUHI and an air urban heat island (AUHI) due to stronger heat storage release in urban areas, while Phoenix only has a SUHI because of enhanced convective heat transfer. Urban-rural differences in aerodynamic features, vegetation and moisture conditions, and heat storage control the magnitude of UHIs or urban cool islands in different regions.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Cenlin He, Olivia Clifton, Emmi Felker-Quinn, S. Ryan Fulgham, Julieta F. Juncosa Calahorrano, Danica Lombardozzi, Gemma Purser, Mj Riches, Rebecca Schwantes, Wenfu Tang, Benjamin Poulter, Allison L. Steiner
Summary: Understanding the interactions between air pollution and terrestrial ecosystems is crucial for predicting the impacts on climate and human health. Coordinated measurements, data standardization, and collaboration across disciplines and regions are key for advancing this understanding.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2021)
Article
Remote Sensing
Haoran Hou, Qianqiu Longyang, Hongbo Su, Ruijie Zeng, Tianfang Xu, Zhi-Hua Wang
Summary: The exacerbated thermal environment in cities, especially the urban heat island (UHI) effect, has led to many adverse urban environmental issues. However, the relative contributions and spatiotemporal variability patterns of different UHI attributes remain unclear. This study used the random forest method to quantify the relative importance of four categories of urban surface characteristics in regulating the surface UHI.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2023)
Article
Plant Sciences
Yiming Liao, Qi Zhou, Xuanqiao Jing
Summary: The study compared six global and regional open datasets for greenspace mapping, finding that the OSM dataset performed best when compared to the OS dataset, and the FROM-GLC10 dataset performed best when compared to sampling points. Most quantitative results using these two open datasets were close to or higher than 80%, indicating their effectiveness for greenspace mapping.
URBAN FORESTRY & URBAN GREENING
(2021)
Article
Environmental Sciences
Hongchao Xu, Chunlin Li, Hao Wang, Rui Zhou, Miao Liu, Yuanman Hu
Summary: This study analyzed the spatiotemporal patterns and characteristics of summer daytime regional urban heat islands (RHI) in the Beijing-Tianjin-Hebei (BTH) urban agglomeration using Modis land surface temperature (LST) data and analytical methods. The results showed a significant and continuous upward trend in relative land surface temperature (RLST) in the southeastern part of BTH with a high level of urbanization. The center of gravity (GC) of RHI gradually shifted to the southeast as urbanization level increased, and the development direction of RHI changed accordingly.
Article
Engineering, Multidisciplinary
Fareeq Tawfeeq Najah, Sally Fakhri Khalaf Abdullah, Tamarah Ameen Abdulkareem
Summary: Urban sprawl has led to changes in landscaping, replacing open areas and green urban spaces with buildings and infrastructure. This transformation has resulted in the Urban Heat Island (UHI) effect, causing urban centers to be warmer than rural areas. The research aims to assess the impact of green urban spaces' area and building formation on the exacerbation of UHI in Baghdad city.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Multidisciplinary Sciences
Yarong Yang, Fan Song, Jie Ma, Zheng Wei, Lili Song, Wei Cao
Summary: Urban heat islands significantly impact the quality of urban habitats. The ongoing process of global urbanization has worsened the urban heat island effect, but urban forestry can help mitigate it. This study focused on Zhengzhou City, China, and measured the changes in the local urban heat island and vegetation coverage from 2006 to 2020. The results showed the expansion of the high-temperature zone in the city and the deterioration and subsequent improvement of the overall urban heat island. The development of vegetation coverage correlated with the improvement of the heat island. The study provides a theoretical basis for future urban and forest construction plans, as well as support for landscape optimization and heat island mitigation.
Article
Geosciences, Multidisciplinary
Z. Q. Xie, Y. Du, Q. Miao, L. L. Zhang, N. Wang
Summary: A new method is proposed to characterize the spatial pattern and scale of regional surface urban heat islands (RSUHIs) in the Yangtze River Delta of China by applying the spatial similarity of land surface temperature (LST) annual cycle in urban agglomerations. This method has good adaptability to complex terrain and climate variations, and can simultaneously identify the RSUHI spatial pattern and scale.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Forestry
Massimo D'Isidoro, Mihaela Mircea, Rafael Borge, Sandro Finardi, David de la Paz, Gino Briganti, Felicita Russo, Giuseppe Cremona, Maria Gabriella Villani, Mario Adani, Gaia Righini, Lina Vitali, Milena Stracquadanio, Rossella Prandi, Giuseppe Carlino
Summary: This study quantifies the impact of urban vegetation on meteorology using the WRF model. The results show that urban vegetation can lower temperatures, increase humidity, and decrease wind speeds. However, the impact of urban vegetation varies depending on the city and season.
Article
Meteorology & Atmospheric Sciences
Dan Li
Summary: The O'KEYPS equation describes how the stability correction function for the mean velocity profile in the atmospheric surface layer varies with the stability parameter, based on interpolation of turbulent eddy viscosity. Comparing this equation with new theoretical developments suggests that Heisenberg's eddy viscosity provides a unifying framework for interpreting the behavior of the mean velocity profile. The empirical coefficient in the O'KEYPS equation, primarily linked to the increase of turbulent eddy size with instability, is modulated by the turbulent Prandtl number and ratio of eddy sizes under convective and neutral conditions.
BOUNDARY-LAYER METEOROLOGY
(2021)
Article
Geosciences, Multidisciplinary
Weilin Liao, Dan Li, Sergey Malyshev, Elena Shevliakova, Honghui Zhang, Xiaoping Liu
Summary: Studies show that in China, both urban and rural areas are experiencing an increase in frequency, intensity, and duration of summertime hot extremes, with compound hot events showing a more significant increase in urban areas. This has important implications for human health.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Liang Wang, Dan Li
Summary: The study finds that during the day, Boston exhibits a surface urban heat island (SUHI) due to higher urban surface resistance, while Phoenix shows a surface urban cool island because of lower urban aerodynamic resistance. At night, Boston has both a SUHI and an air urban heat island (AUHI) due to stronger heat storage release in urban areas, while Phoenix only has a SUHI because of enhanced convective heat transfer. Urban-rural differences in aerodynamic features, vegetation and moisture conditions, and heat storage control the magnitude of UHIs or urban cool islands in different regions.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2021)
Article
Physics, Fluids & Plasmas
Yu Cheng, Qi Li, Dan Li, Pierre Gentine
Summary: This study investigates the impact of buoyancy on the mean potential temperature profile in the atmospheric boundary layer using direct numerical simulations and field observations. The results show that buoyancy does not change the logarithmic nature of the profile, but instead modulates its slope across a wide range of stability parameters.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Environmental Sciences
Tess Parker, Ailie Gallant, Mike Hobbins, David Hoffmann
Summary: Flash droughts can intensify rapidly and last for months regardless of the season, with their prevalence related to phases of the El Nino-Southern Oscillation, offering potential for seasonal-scale prediction. Monitoring precipitation is less effective for capturing the onset of flash drought compared to indices like the Evaporative Demand Drought Index and Evaporative Stress Index.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
David Hoffmann, Ailie J. E. Gallant, Mike Hobbins
Summary: This study explores how global coupled climate models simulate flash drought and the role of precipitation deficits and evaporative demand E-0 in causing flash drought. The results show that precipitation deficits are the main contributor to flash droughts in climate models, with E-0 playing a secondary role. The study also highlights significant differences in the representation of flash drought characteristics among different models, primarily due to an overestimation of E-0.
JOURNAL OF HYDROMETEOROLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Mustapha Adamu, Ailie J. E. Gallant, Shayne McGregor
Summary: This study examines the relationship between low decadal mean precipitation and monthly-scale wet and dry extremes over the global land area. The research found that changes in wet extremes are most significantly associated with low decadal mean precipitation, while shifts in the mean of precipitation distributions play an important, but typically secondary, role in dry decades. There is a negligible role for changes in variance, and a decadal-scale decline in mean precipitation does not necessarily lead to an increase in the severity of seasonal-scale drought.
Article
Environmental Sciences
Chi Chen, Dan Li, Trevor F. Keenan
Summary: Satellite observations show that the surface urban heat island intensity (SUHII) has been increasing over the last two decades, accompanied by an increased urban-rural contrast of vegetation greenness. The study uses a data-model fusion approach to quantify the contribution of uneven vegetation trends in urban and rural areas to the trend of SUHII during the peak growing season. Increasing trend of LAI(dif) accounts for about one quarter of the trend in satellite-derived SUHII, particularly in rapidly urbanizing and intensively cultivated rural areas. Urban greening trends play a crucial role in modulating urban-rural temperature differences.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
P. Vahmani, A. D. Jones, D. Li
Summary: This study finds that the warming climate has minimal implications for evapotranspiration rates and irrigation water demand in California. The regulation of stomata resistance by stressed vegetation offsets the expected increase in evapotranspiration rates caused by the increasing demand for moisture in the warmer atmosphere. The study confirms that plant physiological changes moderate the impact of climate change on actual evapotranspiration.
Article
Meteorology & Atmospheric Sciences
Changxing Lan, Heping Liu, Gabriel G. Katul, Dan Li, Dennis Finn
Summary: In very stable boundary layers, the distortion of the wind profile leads to turbulence generation, increased turbulence intensity and fluxes, and a transition from very stable to weakly stable regimes.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Meteorology & Atmospheric Sciences
Tess Parker, Ailie J. E. Gallant
Summary: This study demonstrates the strong relationship between meteorological droughts in Australia and changes in the occurrence of heavy rainfall events. The occurrence of drought is regulated by changes in days of significant rainfall, which contribute to a majority of the reduction in rainfall during drought development periods and the rainfall surplus during drought recovery periods. The frequency and contribution of heavy rainfall days are both important factors in understanding drought in Australia.
WEATHER AND CLIMATE EXTREMES
(2022)
Article
Environmental Sciences
Linying Wang, Ting Sun, Wenyu Zhou, Maofeng Liu, Dan Li
Summary: The sensitivity of urban canopy air temperature (T-a) to anthropogenic heat flux (Q(AH)) varies with space and time, but the exact factors controlling this variability remain unclear. To understand the contributions of different physical processes to this sensitivity, a forcing-feedback framework based on the energy budget of air within the urban canopy layer was developed and applied to simulate T-a/Q(AH) in the contiguous United States. The results showed that both direct and feedback effects play a role in this sensitivity, with the direct effect being dominant in summer and the feedback effect becoming stronger in winter due to weakened negative feedback associated with heat conductance.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Xin Shao, Ning Zhang, Dan Li, Jianning Sun
Summary: The transition from moderate to weak turbulence regimes in stable atmospheric boundary layers presents a significant challenge for numerical models. This study proposes a critical horizontal Froude number of approximately 0.28 to characterize this transition, which is linked to the development of quasi two-dimensional pancake vortices. These findings can help improve turbulence parameterizations in numerical models for weather and pollutants dispersion.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Zolal Ayazpour, Shiqi Tao, Dan Li, Amy Jo Scarino, Ralph E. E. Kuehn, Kang Sun
Summary: This study aims to generate a spatially complete PBLH product over the contiguous United States. An XGB regression model was developed using selected meteorological and geographical data fields as explanatory variables. The PBLH prediction from this work shows closer agreement with the reference observations compared to the reanalysis products.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Environmental Sciences
Wenyu Zhou, Linying Wang, Dan Li, L. Ruby Leung
Summary: Spatial patterns of lake evaporation increase due to global warming are closely linked to regional hydroclimate drying effects. Future lake evaporation is projected to increase globally, with amplification in areas with drier hydroclimates and dampening in areas with wetter hydroclimates. Coupled changes in lake evaporation and hydroclimate have significant implications for regional water balance and can exacerbate water scarcity and flood risks.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)