scholarly journals An examination of urban heat island characteristics in a global climate model

2010 ◽  
Vol 31 (12) ◽  
pp. 1848-1865 ◽  
Author(s):  
K. W. Oleson ◽  
G. B. Bonan ◽  
J. Feddema ◽  
T. Jackson
Keyword(s):  
Urban Heat Island ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Heat Island ◽  
Urban Heat

scholarly journals Weather Pattern Classification to Represent the Urban Heat Island in Present and Future Climate

2013 ◽  
Vol 52 (12) ◽  
pp. 2699-2714 ◽  
Author(s):  
Peter Hoffmann ◽  
K. Heinke Schlünzen
Keyword(s):  
Urban Heat Island ◽  
Climate Model ◽  
Global Climate Model ◽  
Limited Area ◽  
Climate Projections ◽  
Heat Island ◽  
Cluster Number ◽  
Statistical Measures ◽  
Urban Heat ◽  
Optimal Cluster

AbstractA classification of weather patterns (WP) is derived that is tailored to best represent situations relevant for the urban heat island (UHI). Three different types of k-means-based cluster methods are conducted. The explained cluster variance is used as a measure for the quality. Several variables of the 700-hPa fields from the 40-yr ECMWF Re-Analysis (ERA-40) were tested for the classification. The variables as well as the domain for the clustering are chosen in a way to explain the variability of the UHI as best as possible. It turned out that the combination of geopotential height, relative humidity, vorticity, and the 1000–700-hPa thickness is best suited. To determine the optimal cluster number k several statistical measures are applied. Except for autumn (k = 12) an optimal cluster number of k = 7 is found. The WP frequency changes are analyzed using climate projections of two regional climate models (RCM). Both RCMs, the Regional Model (REMO) and Climate Limited-Area Model (CLM), are driven with the A1B simulations from the global climate model ECHAM5. Focusing on the periods 2036–65 and 2071–2100, no change can be found of the frequency for the anticyclonic WP when compared with 1971–2000. Since these WPs are favorable for the development of a strong UHI, the frequency of strong UHI days stays the same for the city of Hamburg,Germany. For other WPs changes can be found for both future periods. At the end of the century, a large increase (17%–40%) in the frequency of the zonal WP and a large decrease (20%–26%) in the southwesterly WP are projected.

scholarly journals Integration of a Building Energy Model in an Urban Climate Model and its Application

2020 ◽  
Author(s):  
Luxi Jin ◽  
Sebastian Schubert ◽  
Daniel Fenner ◽  
Fred Meier ◽  
Christoph Schneider
Keyword(s):  
Temporal Variation ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Indoor Air ◽  
Climate Model ◽  
Building Energy ◽  
Energy Model ◽  
Heat Island ◽  
Energy Fluxes ◽  
Urban Heat

Abstract We report the ability of an urban canopy model, coupled with a regional climate model, to simulate energy fluxes, the intra-urban variability of air temperature, urban-heat-island characteristics, indoor temperature variation, as well as anthropogenic heat emissions, in Berlin, Germany. A building energy model is implemented into the Double Canyon Effect Parametrization, which is coupled with the mesoscale climate model COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode) and takes into account heat generation within buildings and calculates the heat transfer between buildings and the urban atmosphere. The enhanced coupled urban model is applied in two simulations of 24-day duration for a winter and a summer period in 2018 in Berlin, using downscaled reanalysis data to a final grid spacing of 1 km. Model results are evaluated with observations of radiative and turbulent energy fluxes, 2-m air temperature, and indoor air temperature. The evaluation indicates that the improved model reproduces the diurnal characteristics of the observed turbulent heat fluxes, and considerably improves the simulated 2-m air temperature and urban heat island in winter, compared with the simulation without the building energy model. Our set-up also estimates the spatio–temporal variation of wintertime energy consumption due to heating with canyon geometry. The potential to save energy due to the urban heat island only becomes evident when comparing a suburban site with an urban site after applying the same grid-cell values for building and street widths. In summer, the model realistically reproduces the indoor air temperature and its temporal variation.

scholarly journals Climate change over UK cities: the urban influence on extreme temperatures in the UK climate projections

2021 ◽  
Author(s):  
William J. Keat ◽  
Elizabeth J. Kendon ◽  
Sylvia I. Bohnenstengel
Keyword(s):  
Urban Heat Island ◽  
Rural Areas ◽  
Land Surface ◽  
Urban Areas ◽  
Climate Model ◽  
Climate Projections ◽  
Heat Island ◽  
Night Time ◽  
Urban Heat ◽  
The Uk

AbstractIncreasing summer temperatures in a warming climate will increase the exposure of the UK population to heat-stress and associated heat-related mortality. Urban inhabitants are particularly at risk, as urban areas are often significantly warmer than rural areas as a result of the urban heat island phenomenon. The latest UK Climate Projections include an ensemble of convection-permitting model (CPM) simulations which provide credible climate information at the city-scale, the first of their kind for national climate scenarios. Using a newly developed urban signal extraction technique, we quantify the urban influence on present-day (1981–2000) and future (2061–2080) temperature extremes in the CPM compared to the coarser resolution regional climate model (RCM) simulations over UK cities. We find that the urban influence in these models is markedly different, with the magnitude of night-time urban heat islands overestimated in the RCM, significantly for the warmest nights (up to $$4~^{\circ }$$ 4 ∘ C), while the CPM agrees much better with observations. This improvement is driven by the improved land-surface representation and more sophisticated urban scheme MORUSES employed by the CPM, which distinguishes street canyons and roofs. In future, there is a strong amplification of the urban influence in the RCM, whilst there is little change in the CPM. We find that future changes in soil moisture play an important role in the magnitude of the urban influence, highlighting the importance of the accurate representation of land-surface and hydrological processes for urban heat island studies. The results indicate that the CPM provides more reliable urban temperature projections, due at least in part to the improved urban scheme.

Land Surface Temperature Estimation and Urban Heat Island Detection

2019 ◽  
pp. 1538-1560
Author(s):  
Abhisek Santra
Keyword(s):  
Surface Temperature ◽  
Urban Heat Island ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Global Climate ◽  
Theoretical Background ◽  
Heat Island ◽  
Temperature Estimation ◽  
Urban Heat ◽  
Spatio Temporal

Earth's land surface temperature is considered to be very important for modeling the environment. Following the trend of increasing global population, urban areas are expanding in spatio-temporal domain. In this way it is affecting the urban climate and subsequently the global climate. Thus, scientific understanding is required to conceive the knowledge about interaction between urban land use/land cover and the atmospheric conditions prevailing in that area. In this chapter the land surface temperature estimation and urban heat island detection are perceived from remote sensing perspective. The chapter in this context highlights three major aspects, viz. the theoretical background, description about some of the common thermal sensors and widely used algorithms to retrieve surface temperature from these satellite sensors.

scholarly journals Multi-model comparison of urban heat island modelling approaches

2018 ◽  
Vol 18 (14) ◽  
pp. 10655-10674 ◽  
Author(s):  
Jan Karlický ◽  
Peter Huszár ◽  
Tomáš Halenka ◽  
Michal Belda ◽  
Michal Žák ◽  
...  
Keyword(s):  
Wind Speed ◽  
Urban Heat Island ◽  
Urban Environment ◽  
Model Comparison ◽  
Climate Model ◽  
Heat Island ◽  
Significant Difference ◽  
Urban Heat ◽  
Urban Parameterizations ◽  
The Impact

Abstract. Cities are characterized by different physical properties of surface compared to their rural counterparts, resulting in a specific regime of the meteorological phenomenon. Our study aims to evaluate the impact of typical urban surfaces on the central European urban climate in several model simulations, performed with the Weather Research and Forecasting (WRF) model and Regional Climate Model (RegCM). The specific processes occurring in the typical urban environment are described in the models by various types of urban parameterizations, greatly differing in complexity. Our results show that all models and urban parameterizations are able to reproduce the most typical urban effect, the summer evening and nocturnal urban heat island, with the average magnitude of 2–3 °C. The impact of cities on the wind is clearly dependent on the urban parameterization employed, with more simple ones unable to fully capture the wind speed reduction induced by the city. In the summer, a significant difference in the boundary-layer height (about 25 %) between models is detected. The urban-induced changes of temperature and wind speed are propagated into higher altitudes up to 2 km, with a decreasing tendency of their magnitudes. With the exception of the daytime in the summer, the urban environment improves the weather conditions a little with regard to the pollutant dispersion, which could lead to the partly decreased concentration of the primary pollutants.

scholarly journals Guidance to Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island

2021 ◽  
Author(s):  
K. Heinke Schluenzen ◽  
Sue Grimmond ◽  
Alexander Baklanov
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Global Climate ◽  
Heat Island ◽  
Canopy Layer ◽  
Second Person ◽  
Urban Heat ◽  
The Many ◽  
Definition Of

<p>Today, every second person lives in a city, and urbanization is continuously increasing. For 2050, it is to be expected that 2 out of 3 people will live in a city and thus the vast majority of the world's population will be affected not only by global climate change but also by locally induced climatic changes. The canopy layer urban heat island (CL-UHI) is one of the most well-known meteorological characteristics of urban areas found in cities small and large around the world. Its characteristics differ between cities, across a city and with time. The climate change induced warming cities experience is additionally impacted by the CL-UHI.</p><p>Despite the city-scale importance of CL-UHI, the WMO has not had any specific guidance on this. In response to the request of the 18th World Meteorological Congress (Resolutions 32 and 61) experts from WMO GAW (Global Atmosphere Watch) Urban Research Meteorology and Environment (GURME) initiated in 2020 preparation of a guidance on measuring, modelling and monitoring the CL-UHI. The guidance is a community-based development with 30 contributors providing expertise in all different aspects of CL-UHI. This includes a clear definition of what a CL-UHI is and clarifications of what it is not, how it develops (e.g. meteorological and morphological influences), methods to assess CL-UHI intensities (measurements,  modelling approaches) as well as when its assessment  (applications) is needed and how it can be reduced (or when it is beneficial).</p><p>The presentation will specifically focus on the key questions addressed in the guidance: what a CL-UHI is and what it is not, where CL-UHI values are relevant for and the many challenges that exist in simulating the CL-UHI with different models.</p>

scholarly journals Investigating the Relationship between Human Activity and the Urban Heat Island Effect in Melbourne and Four Other International Cities Impacted by COVID-19

2021 ◽  
Vol 14 (1) ◽  
pp. 378
Author(s):  
Cheuk Yin Wai ◽  
Nitin Muttil ◽  
Muhammad Atiq Ur Rehman Tariq ◽  
Prudvireddy Paresi ◽  
Raphael Chukwuka Nnachi ◽  
...  
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Human Activity ◽  
Global Climate ◽  
Ghg Emissions ◽  
Daily Maximum ◽  
Heat Island ◽  
Urban Resilience ◽  
Urban Heat ◽  
The Relationship

Climate change is one of the biggest challenges of our times, even before the onset of the Coronavirus (COVID-19) pandemic. One of the main contributors to climate change is greenhouse gas (GHG) emissions, which are mostly caused by human activities such as the burning of fossil fuels. As the lockdown due to the pandemic has minimised human activity in major cities, GHG emissions have been reduced. This, in turn, is expected to lead to a reduction in the urban heat island (UHI) effect in the cities. The aim of this paper is to understand the relationship between human activity and the UHI intensity and to provide recommendations towards developing a sustainable approach to minimise the UHI effect and improve urban resilience. In this study, historical records of the monthly mean of daily maximum surface air temperatures collected from official weather stations in Melbourne, New York City, Tokyo, Dublin, and Oslo were used to estimate the UHI intensity in these cities. The results showed that factors such as global climate and geographic features could dominate the overall temperature. However, a direct relationship between COVID-19 lockdown timelines and the UHI intensity was observed, which suggests that a reduction in human activity can diminish the UHI intensity. As lockdowns due to COVID-19 are only temporary events, this study also provides recommendations to urban planners towards long-term measures to mitigate the UHI effect, which can be implemented when human activity returns to normal.

Sign in / Sign up

Export Citation Format

Share Document