scholarly journals Diurnal evolution of urban tree temperature at a city scale

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thuy Trang Vo ◽  
Leiqiu Hu

AbstractDespite the importance of urban trees’ surface temperature in assessing micro-climate interactions between trees and the surrounding environment, their diurnal evolution has been largely understudied at a city-wide scale due to a lack of effective thermal observations. By downscaling ECOSTRESS land surface temperature imaginary over New York City, we provide the first diurnal analysis of city-scale canopy temperature. Research reveals a remarkable spatial variation of the canopy temperature during daytime up to 5.6 K (standard deviation, STD), while the nighttime STD remains low at 1.7 K. Further, our analysis shows that the greenspace coverage and distance to bluespaces play an important role in cooling the local canopy during daytime, explaining 25.0–41.1% of daytime spatial variation of canopy temperatures while surrounding buildings modulate canopy temperature asymmetrically diurnally: reduced daytime warming and reduced nocturnal cooling. Built on space-borne observations and a flexible yet robust statistical method, our research design can be easily transferable to explore urban trees’ response to local climate across cities, highlighting the potentials of advancing the science and technologies for urban forest management.

Author(s):  
Chunhong Zhao

The Local Climate Zones (LCZs) concept was initiated in 2012 to improve the documentation of Urban Heat Island (UHI) observations. Despite the indispensable role and initial aim of LCZs concept in metadata reporting for atmospheric UHI research, its role in surface UHI investigation also needs to be emphasized. This study incorporated LCZs concept to study surface UHI effect for San Antonio, Texas. LCZ map was developed by a GIS-based LCZs classification scheme with the aid of airborne Lidar dataset and other freely available GIS data. Then, the summer LST was calculated based Landsat imagery, which was used to analyse the relations between LST and LCZs and the statistical significance of the differences of LST among the typical LCZs, in order to test if LCZs are able to efficiently facilitate SUHI investigation. The linkage of LCZs and land surface temperature (LST) indicated that the LCZs mapping can be used to compare and investigate the SUHI. Most of the pairs of LCZs illustrated significant differences in average LSTs with considerable significance. The intra-urban temperature comparison among different urban classes contributes to investigate the influence of heterogeneous urban morphology on local climate formation.


Author(s):  
Abdou Bah ◽  
Hamid Norouzi ◽  
Satya Prakash ◽  
Makini Valentine ◽  
Reginald Blake

Urban Climate ◽  
2019 ◽  
Vol 27 ◽  
pp. 259-271 ◽  
Author(s):  
Terence Darlington Mushore ◽  
Timothy Dube ◽  
Moven Manjowe ◽  
Wester Gumindoga ◽  
Abel Chemura ◽  
...  

2020 ◽  
Author(s):  
Anthony Bernus ◽  
Catherine Ottle ◽  
Nina Raoult

<p>Lakes play a major role on local climate and boundary layer stratification. At global scale, they have been shown to have an impact on the energy budget, (see for example Le Moigne et al., 2016 or Bonan, 1995 ) . To represent the energy budget of lakes at a global scale, the FLake (Mironov et al, 2008) lake model has been coupled to the ORCHIDEE land surface model - the continental part of the IPSL earth system model. By including Flake in ORCHIDEE, we aim to improve the representation of land surface temperature and heat fluxes. Using the standard CMIP6 configuration of ORCHIDEE,  two 40-year simulations were generated (one coupled with FLake and one without) using the CRUJRA meteorological forcing data at a spatial resolution of 0.5°. We compare land surface temperatures and heat fluxes from the two ORCHIDEE simulations and assess the impacts of lakes on surface energy budgets. MODIS satellite land surface temperature products will be used to validate the simulations. We expect a better fit between the simulated land surface temperature and the MODIS data when the FLake configuration is used. The preliminary results of the comparison will be presented.</p>


2021 ◽  
Vol 921 (1) ◽  
pp. 012004
Author(s):  
A Ardiyansyah ◽  
A Munir ◽  
A Gabric

Abstract Numerous studies have shown that there is a positive correlation between the increase of urban built-up areas with elevated Surface Urban Heat Island (UHI) temperature. It can be considered that SUHI is a by-product of urbanisation. The study found that SUHI in Makassar City is seasonal dependent. High surface temperature tends to occur in the dry season within the urban centre, expanding to the South-Eastern. Furthermore, by combining land surface temperature and Local Climate Zone (LCZ) classification scheme, 16 out of 17 local climate zones were identified, excluding LCZ 7 (light built) within the observation year. In detailed, the combination of LCZ 3 class (compact low rise) and LCZ 10 class (industrial), occupied more than 80 % of the total built-up category with a surface temperature range of 11° C and 16° C respectively. Furthermore, the result indicates a homogenous surface temperature within LCZ 3 with a lower SD of 1.40° C compared to LCZ 10 of 1.95° C. Also, the study explored the correlation of various urban and non-urban indices using artificial neural network. Based on the model used, the indices showed poor correlation with LCZ 3 but adversely correlates to LCZ 10. A final loss value of 0.222 in LCZ 10 was obtained. In contrast, LCZ 3 resulted in high final loss value of 146.554. The result indicated that there are other variables which should be considered in exploring SUHI correlation within LCZ 3 (compact low rise) in Makassar City. In contrast, LCZ 10 (industrial) correlate positively with three urban indices, consisting of NDBI (43.94), BI (37.79), and NDBal (34.77). In brief, the result indicated that SUHI phenomenon in LCZ 3 was poorly represented by the model, whereas the level of city development can be predicted better using LCZ 10 (industrial) areas.


2021 ◽  
Vol 333 ◽  
pp. 02008
Author(s):  
Anna Gosteva ◽  
Sofia Ilina ◽  
Aleksandra Matuzko

The replacement of the natural landscape by artificial environment has led to changes in the ecosystem and physical properties of the surface, such as heat storage capacity, and thermal conductivity properties. These changes increase the difficulty of heat transfer between urban areas and the environment. Land surface temperature (LST) images from various satellites are widely used to represent urban thermal environments, which are more convenient and intuitive way. LST maps provide full spatial coverage, which distinguishes them from air temperature data obtained from meteorological stations. The study of LST according to the Landsat 8 data of Krasnoyarsk city over the past 10 years allowed the authors to talk about the observation of constant seasonal urban heat islands (UHI). For a more detailed consideration of the urban environment, this study further considers urban landscapes, thus the idea of local climate zone (LCZ) is introduced to study these diverse impacts in addition to the traditional map of LST. And analysis of the interaction of UHI and LCZ.


Sign in / Sign up

Export Citation Format

Share Document