Corrigendum to “The future urban heat-wave challenge in Africa: Exploratory analysis” [Global Environ. Change 66 (2021) 102190]

During late July and early August 2008, an intense heat wave occurred in Oklahoma City. To quantify the impact of the urban heat island (UHI) in Oklahoma City on observed and apparent temperature conditions during the heat wave event, this study used observations from 46 locations in and around Oklahoma City. The methodology utilized composite values of atmospheric conditions for three primary categories defined by population and general land use: rural, suburban, and urban. The results of the analyses demonstrated that a consistent UHI existed during the study period whereby the composite temperature values within the urban core were approximately C warmer during the day than the rural areas and over C warmer at night. Further, when the warmer temperatures were combined with ambient humidity conditions, the composite values consistently revealed even warmer heat-related variables within the urban environment as compared with the rural zone.

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Historical and future temporal trends in the summer Urban Heat Island of Athens (Greece)

10.5194/ems2021-318 ◽

2021 ◽

Author(s):

Tim van der Schriek ◽

Konstantinos V. Varotsos ◽

Dimitra Founda ◽

Christos Giannakopoulos

Keyword(s):

Climate Change ◽

Air Pollution ◽

Air Temperature ◽

Temporal Trends ◽

Temperature Data ◽

Climate Change Scenarios ◽

Heat Island ◽

Hot Days ◽

The Future ◽

Urban Heat

Historical changes, spanning 1971&#8211;2016, in the Athens Urban Heat Island (UHI) over summer were assessed by contrasting two air temperature records from established meteorological stations in urban and rural settings. When contrasting two 20-year historical periods (1976&#8211;1995 and 1996&#8211;2015), there is a significant difference in summer UHI regimes. The stronger UHI-intensity of the second period (1996&#8211;2015) is likely linked to increased pollution and heat input. Observations suggest that the Athens summer UHI characteristics even fluctuate on multi-annual basis. Specifically, the reduction in air pollution during the Greek Economic Recession (2008-2016) probable subtly changed the UHI regime, through lowering the frequencies of extremely hot days (Tmax > 37 &#176;C) and nights (Tmin > 26 &#176;C).Subsequently, we examined the future temporal trends of two different UHIs in Athens (Greece) under three climate change scenarios. A five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11&#176; (~12 &#215; 12 km) simulated air temperature data, spanning the period 1976&#8211;2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5 and RCP8.5) were implanted in the simulations after 2005. The observed daily maximum and minimum air temperature data (Tmax and Tmin) from two historical UHI regimes (1976&#8211;1995 and 1996&#8211;2015, respectively) were used, separately, to bias-adjust the model simulations thus creating two sets of results.This novel approach allowed us to assess future temperature developments in Athens under two different UHI intensity regimes. We found that the future frequency of days with Tmax > 37 &#176;C in Athens was only different from rural background values under the intense UHI regime. There is a large increase in the future frequency of nights with Tmin > 26 &#176;C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site.This study shows a large urban amplification of the frequency of extremely hot days and nights which is likely forced by increasing air pollution and heat input. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be also effective in reducing urban temperatures during extreme heat events in Athens under all future climate change scenarios. Such policies therefore have multiple benefits, including: reducing electricity (energy) needs, improving living quality and decreasing heat- and pollution related illnesses/deaths.&#160;

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An analysis of urban heat island impact toward increasing of afternoon thunderstorm frequency in Taipei, Taiwan

10.5194/egusphere-egu21-10522 ◽

2021 ◽

Author(s):

Siti Talitha Rachma ◽

Yuan-Chien Lin

Keyword(s):

Urban Heat Island ◽

Empirical Orthogonal Function ◽

Precipitation Pattern ◽

Heat Island ◽

Hilbert Huang Transform ◽

Orthogonal Function ◽

Hourly Temperature ◽

Taipei City ◽

The Future ◽

Urban Heat

Each year, average of Earth&#8217;s temperature rises and the urbanized cities, are warming at a significant rate than the surrounding rural areas. This phenomenon is called Urban Heat Island (UHI). UHI is a consequence of human activities in urban area and it has possibilities to impact weather and climate on regional or global scale. Precipitation is one of the basic hydro-meteorological phenomena that could be affected by UHI trend with thunderstorm as a part of precipitation. As the UHI level rises from year to year, the pattern of precipitation could change. However, this issue is still underdeveloped, thus, this work tries to comprehensively understand the hydrological response to UHI.&#160;This research selects Taipei city as the study area and explores the connection between UHI and precipitation pattern&#8217;s change. The data used here are hourly temperature and precipitation data collected from 21 Taipei weather stations collected from Central Weather Bureau (CWB) Taiwan. In order to reveal specific details and trend of non-linear relation from both time domain and frequency, Hilbert-Huang Transform (HHT) is adopted in this study. The HHT results are compared between each station. Later, empirical orthogonal function (EOF) also being used to extract main spatial pattern of precipitation in Taipei city.&#160;The results show that the urbanization in Taipei city contribute to increasing trend of 0.5 &#8211; 1 oC in daily UHI and also increase of 27% in the afternoon thunderstorm frequency for this past 20 years. The increase of thunderstorm would result into a bigger rain water flow to the river and a fewer time for it to percolate to the ground. If there are more thunderstorms in the future, it is possible the phenomenon could lead to the lack of groundwater discharge and depletion of groundwater reserve. This result could be utilized in the future to understand more about UHI mitigation and thunderstorm in Taipei.&#160;Keywords: urban heat island, thunderstorm, Hilbert-Huang Transform, empirical orthogonal function

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Spatio -temporal variations in urban heat island and its interaction with heat wave

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/j.jastp.2019.02.001 ◽

2019 ◽

Vol 185 ◽

pp. 50-57 ◽

Cited By ~ 15

Author(s):

Shahnilla Haider Rizvi ◽

Khan Alam ◽

Muhammad Jawed Iqbal

Keyword(s):

Urban Heat Island ◽

Heat Wave ◽

Temporal Variations ◽

Heat Island ◽

Urban Heat ◽

Spatio Temporal

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Amplified Urban Heat Islands during Heat Wave Periods

Journal of Geophysical Research Atmospheres ◽

10.1029/2018jd030230 ◽

2019 ◽

Vol 124 (14) ◽

pp. 7797-7812 ◽

Cited By ~ 11

Author(s):

Shaojing Jiang ◽

Xuhui Lee ◽

Jiankai Wang ◽

Kaicun Wang

Keyword(s):

Heat Wave ◽

Urban Heat Islands ◽

Heat Islands ◽

Urban Heat

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An integrated approach to project the future urban climate response: Changes to Lisbon's urban heat island and temperature extremes

Urban Climate ◽

10.1016/j.uclim.2020.100683 ◽

2020 ◽

Vol 34 ◽

pp. 100683

Author(s):

Miguel Nogueira ◽

Daniela C.A. Lima ◽

Pedro M.M. Soares

Keyword(s):

Urban Heat Island ◽

Urban Climate ◽

Integrated Approach ◽

Temperature Extremes ◽

Heat Island ◽

Climate Response ◽

The Future ◽

Urban Heat

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An Observational Case Study of Synergies between an Intense Heat Wave and the Urban Heat Island in Beijing

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-19-0125.1 ◽

2020 ◽

Vol 59 (4) ◽

pp. 605-620 ◽

Cited By ~ 3

Author(s):

Ning An ◽

Jingjing Dou ◽

Jorge E. González-Cruz ◽

Robert D. Bornstein ◽

Shiguang Miao ◽

...

Keyword(s):

Boundary Layer ◽

Urban Heat Island ◽

Heat Wave ◽

Apparent Temperature ◽

Heat Index ◽

Heat Island ◽

Canopy Layer ◽

Urban Heat ◽

Peak Pattern ◽

Intense Heat

AbstractThe focus of this study is an intense heat episode that occurred on 9–13 July 2017 in Beijing, China, that resulted in severe impacts on natural and human variables, including record-setting daily electricity consumption levels. This event was observed and analyzed with a suite of local and mesoscale instruments, including a high-density automated weather station network, soil moisture sensors, and ground-based vertical instruments (e.g., a wind profiler, a ceilometer, and three radiometers) situated in and around the city, as well as electric power consumption data and analysis data from the U.S. National Centers for Environmental Prediction. The results show that the heat wave originated from dry adiabatic warming induced by the dynamic downslope and synoptic subsidence. The conditions were aggravated by the increased air humidity during subsequent days, which resulted in historically high records of the heat index (i.e., an index representing the apparent temperature that incorporates both air temperature and moisture). The increased thermal energy and decreased boundary layer height resulted in a highly energized urban boundary layer. The differences between urban and rural thermal conditions throughout almost the entire boundary layer were enhanced during the heat wave, and the canopy-layer urban heat island intensity (UHII) reached up to 8°C at a central urban station at 2300 local standard time 10 July. A double-peak pattern in the diurnal cycle of UHIIs occurred during the heat wave and differed from the single-peak pattern of the decadal average UHII cycles. Different spatial distributions of UHII values occurred during the day and night.

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Can climate adaptation solutions fix the urban heat island? An assessment of the thermal conditions during heat waves in Vienna impacted by climate change and urban development scenarios for the mid-21st-century

10.5194/egusphere-egu2020-8668 ◽

2020 ◽

Author(s):

Paul Hamer ◽

Heidelinde Trimmel ◽

Philipp Weihs ◽

Stéphanie Faroux ◽

Herbert Formayer ◽

...

Keyword(s):

Climate Change ◽

Urban Heat Island ◽

Heat Wave ◽

Air Temperature ◽

Urban Areas ◽

Climate Adaptation ◽

Heat Waves ◽

Heat Island ◽

Human Thermal Comfort ◽

Urban Heat

Climate change threatens to exacerbate existing problems in urban areas arising from the urban heat island. Furthermore, expansion of urban areas and rising urban populations will increase the numbers of people exposed to hazards in these vulnerable areas. We therefore urgently need study of these environments and in-depth assessment of potential climate adaptation measures.We present a study of heat wave impacts across the urban landscape of Vienna for different future development pathways and for both present and future climatic conditions. We have created two different urban development scenarios that estimate potential urban sprawl and optimized development concerning future building construction in Vienna and have built a digital representation of each within the Town Energy Balance (TEB) urban surface model. In addition, we select two heat waves of similar frequency of return representative for present and future conditions (following the RCP8.5 scenario) of the mid 21st century and use the Weather Research and Forecasting Model (WRF) to simulate both heat wave events. We then couple the two representations urban Vienna in TEB with the WRF heat wave simulations to estimate air temperature, surface temperatures and human thermal comfort during the heat waves. We then identify and apply a set of adaptation measures within TEB to try to identify potential solutions to the problems associated with the urban heat island.Global and regional climate change under the RCP8.5 scenario causes the future heat wave to be more severe showing an increase of daily maximum air temperature in Vienna by 7 K; the daily minimum air temperature will increase by 2-4 K. We find that changes caused by urban growth or densification mainly affect air temperature and human thermal comfort local to where new urbanisation takes place and does not occur significantly in the existing central districts.Exploring adaptation solutions, we find that a combination of near zero-energy standards and increasing albedo of building materials on the city scale accomplishes a maximum reduction of urban canyon temperature of 0.9 K for the minima and 0.2 K for the maxima. Local scale changes of different adaption measures show that insulation of buildings alone increases the maximum wall surface temperatures by more than 10 K or the maximum mean radiant temperature (MRT) in the canyon by 5 K.&#160; Therefore, additional adaptation to reduce MRT within the urban canyons like tree shade are needed to complement the proposed measures.This study concludes that the rising air temperatures expected by climate change puts an unprecedented heat burden on Viennese inhabitants, which cannot easily be reduced by measures concerning buildings within the city itself. Additionally, measures such as planting trees to provide shade, regional water sensitive planning and global reduction of greenhouse gas emissions in order to reduce temperature extremes are required.We are now actively seeking to apply this set of tools to a wider set of cases in order to try to find effective solutions to projected warming resulting from climate change in urban areas.

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