High‐Resolution, Multilayer Modeling of Singapore's Urban Climate Incorporating Local Climate Zones

Surface (2 m) temperature and specific humidity data are measured at 5-minute intervals in a network comprising 33 stations distributed across the city of Berlin, Germany. These data are utilized in order to validate a LES (large eddy simulation) model designed to assess the local climate at a very high resolution of 10 m to 1 m. This model, was developed at the &#8203;Institute of Meteorology and Climatology (IMUK) of the Leibniz Universit&#228;t Hannover, Germany, and is developed into an application tool for city planners within the funding programme "[UC&#178;] - Urban Climate under Change", of the German Federal Ministry of Education and Research (BMBF).The evaluation distinguishes between the different Local climate zones (LCZ) in the city, which are defined following the concept of Stewart & Oke (2012). For Berlin, the following LCZ have been identified: 2 (compact midrise), 4 (open high-rise), 6 (open low-rise), 8 (large low-rise), A (dense trees), B (scattered trees), D (low Plants), G (water).We analyzed one cold winter day during an intensive observation period from 06 UTC on 17th January to 06 UTC on 18th January, 2017. The minimum and maximum recorded temperatures were -8.1 &#176;C and +2 &#176;C, respectively, the sun shine duration was 6.5 hours. Daily and hourly mean absolute error, mean square error and root mean square error confirm that the deviation between measurements and the PALM-4U model differs between the LCZ for Berlin, with particularly large negative deviations of up to 5 K in forest areas, as they are not yet well represented in the model. Smallest deviations are found for the industrial zone. In all cases, the observed amplitude of the diurnal cycle is underestimated. The role of the driving model for the deviations found is addressed.Stewart, I.D., Oke, T.R. (2012) Local climate zones for urban temperature studies. Bull. Amer. Meteor. Soc. 93 1879-1900. DOI: 10.1175/BAMS-D-11-00019.1.&#160;

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Mapping Local Climate Zones and Their Applications in European Urban Environments: A Systematic Literature Review and Future Development Trends

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10040260 ◽

2021 ◽

Vol 10 (4) ◽

pp. 260

Author(s):

Michal Lehnert ◽

Stevan Savić ◽

Dragan Milošević ◽

Jelena Dunjić ◽

Jan Geletič

Keyword(s):

Urban Areas ◽

Urban Climate ◽

Well Being ◽

Climatic Conditions ◽

Urban Environments ◽

Outdoor Thermal Comfort ◽

Climate Zones ◽

Local Climate ◽

Local Climate Zones ◽

Scale Modelling

In the light of climate change and burgeoning urbanization, heat loads in urban areas have emerged as serious issues, affecting the well-being of the population and the environment. In response to a pressing need for more standardised and communicable research into urban climate, the concept of local climate zones (LCZs) has been created. This concept aims to define the morphological types of (urban) surface with respect to the formation of local climatic conditions, largely thermal. This systematic review paper analyses studies that have applied the concept of LCZs to European urban areas. The methodology utilized pre-determined keywords and five steps of literature selection. A total of 91 studies were found eligible for analysis. The results show that the concept of LCZs has been increasingly employed and become well established in European urban climate research. Dozens of measurements, satellite observations, and modelling outcomes have demonstrated the characteristic thermal responses of LCZs in European cities. However, a substantial number of the studies have concentrated on the methodological development of the classification process, generating a degree of inconsistency in the delineation of LCZs. Recent trends indicate an increasing prevalence of the accessible remote-sensing based approach over accurate GIS-based methods in the delineation of LCZs. In this context, applications of the concept in fine-scale modelling appear limited. Nevertheless, the concept of the LCZ has proven appropriate and valuable to the provision of metadata for urban stations, (surface) urban heat island analysis, and the assessment of outdoor thermal comfort and heat risk. Any further development of LCZ mapping appears to require a standardised objective approach that may be globally applicable.

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Impact of Land Cover Composition and Structure on Air Temperature Based on the Local Climate Zone Scheme in Hangzhou, China

Atmosphere ◽

10.3390/atmos12080936 ◽

2021 ◽

Vol 12 (8) ◽

pp. 936

Author(s):

Hai Yan ◽

Shimin Yang ◽

Xiaohui Guo ◽

Fan Wu ◽

Renwu Wu ◽

...

Keyword(s):

Land Cover ◽

Air Temperature ◽

Temperature Difference ◽

Thermal Environment ◽

Urban Climate ◽

Rapid Urbanization ◽

Climate Zones ◽

Local Climate ◽

Composition And Structure ◽

Local Climate Zones

At present, conflicts between urban development and the climate environment are becoming increasingly apparent under rapid urbanization in China. Revealing the dynamic mechanism and controlling factors of the urban outdoor thermal environment is the necessary theoretical preparation for regulating and improving the urban climate environment. Taking Hangzhou as an example and based on the local climate zones classification system, we investigated the effects of land cover composition and structure on temperature variability at the local scale. The measurement campaign was conducted within four local climate zones (LCZ 2, 4, 5, and LCZ 9) during 7 days in the summer of 2018. The results showed that the temperature difference within the respective LCZ was always below 1.1 °C and the mean temperature difference between LCZs caused by different surface physical properties was as high as 1.6 °C at night. Among four LCZs, LCZ 2 was always the hottest, and LCZ 9 was the coolest at night. In particular, the percentage of pervious surface was the most important land cover feature in explaining the air temperature difference. For both daytime and nighttime, increasing the percentage of pervious surface as well as decreasing the percentage of impervious surface and the percentage of building surface could lower the local temperature, with the strongest influence radius range from 120 m to 150 m. Besides, the temperature increased with the SVF increased at day and opposite at night.

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