Observed Spatial Characteristics of Beijing Urban Climate Impacts on Summer Thunderstorms

2015 ◽  
Vol 54 (1) ◽  
pp. 94-105 ◽  
Author(s):  
Jingjing Dou ◽  
Yingchun Wang ◽  
Robert Bornstein ◽  
Shiguang Miao
Keyword(s):  
Urban Area ◽  
Urban Climate ◽  
Climate Impacts ◽  
Interactive Effects ◽  
Specific Humidity ◽  
Heat Island ◽  
Urban Center ◽  
Breeze Circulation ◽  
Mountain Valley ◽  
Urban Heat

AbstractThis study investigates interactive effects from the Beijing urban area on temperature, humidity, wind speed and direction, and precipitation by use of hourly automatic weather station data from June to August 2008–12. Results show the Beijing summer urban heat island (UHI) as a multicenter distribution (corresponding to underlying land-use features), with stronger nighttime than daytime values (averages of 1.7° vs 0.8°C, respectively). Specific humidity was lower in urban Beijing than in surrounding nonurban areas, and this urban dry island is stronger during day than night (maximum of −2.4 vs −1.9 g kg−1). Wind direction is affected by both a mountain–valley-breeze circulation and by urbanization. Morning low-level flows converged into the strong UHI, but afternoon and evening southerly winds were bifurcated by an urban building-barrier-induced divergence. Summer thunderstorms also thus bifurcated and bypassed the urban center because of the building-barrier effect during both daytime and nighttime weak-UHI (<1.25°C) periods. This produced a regional-normalized rainfall (NR) minimum in the urban center and directly downwind of the urban area (of up to −35%), with maximum values along its downwind lateral edges (of >15%). Strong UHIs (>1.25°C), however, induced or enhanced thunderstorm formation (again day and night), which produced an NR maximum in the most urbanized area of up to 75%.

scholarly journals Comments about Urban Bioclimate Aspects for Consideration in Urban Climate and Planning Issues in the Era of Climate Change

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 546
Author(s):  
Andreas Matzarakis
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Urban Climate ◽  
Heat Island ◽  
Adaptation Measures ◽  
Mitigation And Adaptation ◽  
Urban Heat

In the era of climate change, before developing and establishing mitigation and adaptation measures that counteract urban heat island (UHI) effects [...]

scholarly journals Including Urban Heat Island in Bioclimatic Early-Design Phases: A Simplified Methodology and Sample Applications

2021 ◽  
Vol 13 (11) ◽  
pp. 5918
Author(s):  
Giacomo Chiesa ◽  
Yingyue Li
Keyword(s):  
Urban Heat Island ◽  
Urban Climate ◽  
Temperate Climate ◽  
Heat Island ◽  
Climate Data ◽  
Degree Days ◽  
Climate Conditions ◽  
Early Design ◽  
Correct Definition ◽  
Urban Heat

Urban heat island and urban-driven climate variations are recognized issues and may considerably affect the local climatic potential of free-running technologies. Nevertheless, green design and bioclimatic early-design analyses are generally based on typical rural climate data, without including urban effects. This paper aims to define a simple approach to considering urban shapes and expected effects on local bioclimatic potential indicators to support early-design choices. Furthermore, the proposed approach is based on simplifying urban shapes to simplify analyses in early-design phases. The proposed approach was applied to a sample location (Turin, temperate climate) and five other climate conditions representative of Eurasian climates. The results show that the inclusion of the urban climate dimension considerably reduced rural HDD (heating degree-days) from 10% to 30% and increased CDD (cooling degree-days) from 70% to 95%. The results reveal the importance of including the urban climate dimension in early-design phases, such as building programming in which specific design actions are not yet defined, to support the correct definition of early-design bioclimatic analyses.

LCZ scheme for assessing Urban Heat Island intensity in a complex urban area (Beirut, Lebanon)

Urban Climate ◽  
2021 ◽  
Vol 37 ◽  
pp. 100846
Author(s):  
Nada Badaro-Saliba ◽  
Jocelyne Adjizian-Gerard ◽  
Rita Zaarour ◽  
Georges Najjar
Keyword(s):  
Urban Heat Island ◽  
Urban Area ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Urban Heat

Urban heat island estimation from improved selection of urban and rural stations by DTW algorithm

2021 ◽  
Author(s):  
Yonghong Hu ◽  
Gensuo Jia ◽  
Jinlong Ai ◽  
Yong Zhang ◽  
Meiting Hou ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Climate ◽  
Global Scale ◽  
Heat Island ◽  
Climate Effect ◽  
Urban Heat ◽  
The Difference ◽  
Temperature Records ◽  
Dynamic Time ◽  
Selection Of

Abstract Typical urban and rural temperature records are essential for the estimation and comparison of urban heat island effects in different regions, and the key issues are how to identify the typical urban and rural stations. This study tried to analyze the similarity of air temperature sequences by using dynamic time warping algorithm (DTW) to improve the selection of typical stations. We examined the similarity of temperature sequences of 20 stations in Beijing and validated by remote sensing, and the results indicated that DTW algorithm could identify the difference of temperature sequence, and clearly divide them into different groups according to their probability distribution information. The analysis for station pairs with high similarity could provide appropriate classification for typical urban stations (FT, SY, HD, TZ, CY, CP, MTG, BJ, SJS, DX, FS) and typical rural stations (ZT, SDZ, XYL) in Beijing. We also found that some traditional rural stations can’t represent temperature variation in rural surface because of their surrounding environments highly modified by urbanization process in last decades, and they may underestimate the urban climate effect by 1.24℃. DTW algorithm is simple in analysis and application for temperature sequences, and has good potentials in improving urban heat island estimation in regional or global scale by selecting more appropriate temperature records.

scholarly journals Local Weather Types by Thermal Periods: Deepening the Knowledge about Lisbon’s Urban Climate

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 840
Author(s):  
Cláudia Reis ◽  
António Lopes ◽  
Ezequiel Correia ◽  
Marcelo Fragoso
Keyword(s):  
Hot Spots ◽  
Urban Areas ◽  
Urban Climate ◽  
Specific Humidity ◽  
Air Masses ◽  
Air Temperatures ◽  
Hourly Data ◽  
Urban Heat ◽  
Thermal Patterns ◽  
Local Weather

Urbanized hot spots incorporate a great diversity of microclimates dependent, among other factors, on local meteorological conditions. Until today, detailed analysis of the combination of climatic variables at local scale are very scarce in urban areas. Thus, there is an urgent need to produce a Local Weather Type (LWT) classification that allows to exhaustively distinguish different urban thermal patterns. In this study, hourly data from air temperature, wind speed and direction, accumulated precipitation, cloud cover and specific humidity (2009–2018) were integrated in a cluster analysis (K-means) in order to produce a LWT classification for Lisbon’s urban area. This dataset was divided by daytime and nighttime and thermal periods, which were generated considering the annual cycle of air temperatures. Therefore, eight LWT sets were generated. Results show that N and NW LWT are quite frequent throughout the year, with a moderate speed (daily average of 4–6 m/s). In contrast, the frequency of rainy LWT is considerably lower, especially in summer (below 10%). Moreover, during this season the moisture content of the air masses is higher, particularly at night. This methodology will allow deepening the knowledge about the multiple Urban Heat Island (UHI) patterns in Lisbon.

scholarly journals Urban heat island intensity and its mitigation strategies in the fast-growing urban area

2020 ◽  
Vol 9 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Shweta Jain ◽  
Srikanta Sannigrahi ◽  
Somnath Sen ◽  
Sandeep Bhatt ◽  
Suman Chakraborti ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Area ◽  
Mitigation Strategies ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Fast Growing ◽  
Urban Heat

scholarly journals Advantages of using a fast urban boundary layer model as compared to a full mesoscale model to simulate the urban heat island of Barcelona

2016 ◽  
Vol 9 (12) ◽  
pp. 4439-4450 ◽  
Author(s):  
Markel García-Díez ◽  
Dirk Lauwaet ◽  
Hans Hooyberghs ◽  
Joan Ballester ◽  
Koen De Ridder ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Simple Model ◽  
Wind Speed ◽  
Mesoscale Model ◽  
Urban Climate ◽  
Urban Canopy ◽  
Forecast Model ◽  
Heat Island ◽  
Layer Model ◽  
Urban Heat

Abstract. As most of the population lives in urban environments, the simulation of the urban climate has become a key problem in the framework of the climate change impact assessment. However, the high computational power required by high-resolution (sub-kilometre) fully coupled land–atmosphere simulations using urban canopy parameterisations is a severe limitation. Here we present a study on the performance of UrbClim, an urban boundary layer model designed to be several orders of magnitude faster than a full-fledged mesoscale model. The simulations are evaluated with station data and land surface temperature observations from satellites, focusing on the urban heat island (UHI). To explore the advantages of using a simple model like UrbClim, the results are compared with a simulation carried out with a state-of-the-art mesoscale model, the Weather Research and Forecasting Model, which includes an urban canopy model. This comparison is performed with driving data from ERA-Interim reanalysis (70 km). In addition, the effect of using driving data from a higher-resolution forecast model (15 km) is explored in the case of UrbClim. The results show that the performance of reproducing the average UHI in the simple model is generally comparable to the one in the mesoscale model when driven with reanalysis data (70 km). However, the simple model needs higher-resolution data from the forecast model (15 km) to correctly reproduce the variability of the UHI at a daily scale, which is related to the wind speed. This lack of accuracy in reproducing the wind speed, especially the sea-breeze daily cycle, which is strong in Barcelona, also causes a warm bias in the reanalysis driven UrbClim run. We conclude that medium-complexity models as UrbClim are a suitable tool to simulate the urban climate, but that they are sensitive to the ability of the input data to represent the local wind regime. UrbClim is a well suited model for impact and adaptation studies at city scale without high computing requirements, but does not replace the need for mesoscale atmospheric models when the focus is on the two-way interactions between the city and the atmosphere.

Climate Bubbles: Games to Monitor Urban Climate

Leonardo ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 64-65
Author(s):  
Drew Hemment ◽  
Carlo Buontempo ◽  
Alfie Dennen
Keyword(s):  
Urban Heat Island ◽  
Air Flow ◽  
Urban Climate ◽  
Heat Island ◽  
Local Climate ◽  
Flow Circulation ◽  
Urban Heat ◽  
The City

Climate Bubbles was a playful, participatory mass observation project on local climate. Bubble blowing games were devised to enable people across the city of Manchester to test air flow circulation and, by sharing the results online, enabled the Met Office to create a snapshot of the effect the Urban Heat Island has on wind.

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