scholarly journals Assessing the long-term urban heat island in San Antonio, Texas based on moderate resolution imaging spectroradiometer/Aqua data

2010 ◽  
Vol 4 (1) ◽  
pp. 043508 ◽  
Author(s):  
Ni-Bin Chang
2020 ◽  
Vol 14 (2) ◽  
pp. 5-27
Author(s):  
Ștefănel–Claudiu Crețu ◽  
Pavel Ichim ◽  
Lucian Sfîcă

The paper presents the main features of the urban heat island of Galați city during the summer season for a period of 16 years (2003-2018) using MODIS products. The main objectives were to analyse the extension and geometry of the urban heat island (UHI), its intensity, as well as its connection with land cover. The study is based on LST (Land Surface Temperature), a product obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors located on board of the Terra (EOS AM-1) satellite since 2001 and Aqua (EOS PM-1) satellite since 2003. The boundaries, geometry and spatial extent of the UHI were delimited primarily through the Rodionov test. Through this method, the changing points along four transects over Galați city were identified (North-South, East-West, Northeast-Southwest and Northwest-Southeast) and have been used to delimitate the UHI. Overall, the Galați UHI assessed by satellite information is stronger during the day when the UHI is split in two centres, developed over the industrial area in the west and over the residential part of the town in the east, while during the night the UHI is weaker being developed more clearly over the oldest part of the city. One of the major characteristics of the Galați UHI is that it is highly influenced by the water bodies encircling the city. During the day the intensity of UHI reaches 2-2.5°C while during the night decreases below 2.0°C. The relation of the UHI with land cover and the attenuation of UHI in the surrounding area are also investigated.


2012 ◽  
Vol 25 (18) ◽  
pp. 6193-6201 ◽  
Author(s):  
Menglin S. Jin

Abstract A new index of calculating the intensity of urban heat island effects (UHI) for a city using satellite skin temperature and land cover observations is recommended. UHI, the temperature difference between urban and rural regions, is traditionally identified from the 2-m surface air temperatures (i.e., the screen-level temperature T2m) measured at a pair of weather stations sited in urban and rural locations. However, such screen-level UHI is affected by the location, distance, and geographic conditions of the pair of weather stations. For example, choosing a different pair of rural and city sites leads to a different UHI intensity for the same city, due to the high heterogeneity of the urban surface temperature. To avoid such uncertainty, satellite-observed surface skin temperature measurements (i.e., skin level temperature Tskin) is recommended to record UHI, known as skin-level UHI or UHIskin. This new index has advantages of high spatial resolution and aerial coverage to better record UHI intensity than T2m. An assessment of skin-level UHI from 10 yr of the National Aeronautics and Space Administration (NASA)’s Moderate Resolution Imaging Spectroradiometer (MODIS) observations reveals that skin-level UHI has a strong UHI signal during the day and at night. In addition, there are significant diurnal and seasonal variations in skin-level UHI. Furthermore, the skin-level UHI is stronger during the day and summer (July) than during nighttime and winter. This new index is important for more uniformly assessing UHIs over cities around the globe. Nevertheless, whether the seasonality and diurnal variations revealed in this work using skin-level UHI index are valid over desert cities, such as Phoenix, Arizona, need to be examined.


2014 ◽  
Vol 53 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Ning Zhang ◽  
Yan Chen

AbstractThe urban heat island (UHI) effect is one of the most significant phenomena caused by urbanization. This study investigated the UHI effect in the Suzhou–Wuxi area, China, on 19–20 August 2010. Using a combination of meteorological station observations and Moderate Resolution Imaging Spectroradiometer (MODIS) surface skin temperature observations, this study demonstrated that an upwind UHI had an exacerbating influence on the downwind UHI during the study period. Numerical simulations using the Weather Research and Forecasting model also proved the importance of an upwind UHI influence on the leeward UHI in this area. For the near-surface UHI, the windward UHI effect is stronger at night than during the daytime because the background atmospheric stratification is more stable and the local lake breeze is weaker at night. However, in the daytime, a greater stability formed over the downwind city because of the warmer air heated by the windward urban area in the upper part of the planetary boundary layer and the cooler air transported from Tai Lake and the rural area in the lower part of the boundary layer. In comparison with the heating effect of a single city, the upwind UHI led to a decrease in the vertical wind speed of approximately 30% (from 0.15 to 0.10 m s−1) in the upper boundary layer over the downwind city and also reduced the near-surface turbulent movement by 25% (from 0.73 to 0.55 m2 s−2). These results improve the understanding of the overall influence of urban clusters on local synoptic/climate processes.


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.


2004 ◽  
Vol 39 ◽  
pp. 223-230 ◽  
Author(s):  
Ian C. Brown ◽  
Ted A. Scambos

AbstractWe use satellite images to track seasonal and interannual variations in blue-ice extent over the past 30 years near Byrd Glacier on the East Antarctic plateau. The study areas have low slope and few nearby nunataks, which may increase their climate sensitivity. A threshold-based algorithm sensitive to snow grain-size is used to analyze 56 Moderate Resolution Imaging Spectroradiometer (MODIS) images over three recent summer seasons. Seasonal blue-ice exposure grows rapidly in late spring, and peaks by late December. Exposure is relatively constant between late December and mid-January, then declines in February. We interpret this cycle as due to removal and re-accumulation of patchy snow. Interannual changes in blue-ice area may be estimated by tracking the near-constant summer maximum extent period. Fifteen mid-summer Landsat images, spanning 1974–2002, were analyzed to determine long-term variations. Interannual area changes are 10–30%; however, the MODIS data revealed that the exposed blue-ice area can be sharply reduced for up to 2 weeks after a snowfall event; and in the 2001/02 season, patchy snow cover persisted for the entire summer. The combination of MODIS seasonal and Landsat interannual data indicates that blue-ice areas can be climate-sensitive. The strong feedback between snow cover and surface energy balance implies that blue-ice areas could rapidly decrease due to climate-related increases in snowfall or reduced ablation.


Author(s):  
Daniel C. Boice ◽  
Michelle E. Garza ◽  
Susan E. Holmes

2020 ◽  
Vol 9 (2) ◽  
pp. e020
Author(s):  
Illyani Ibrahim ◽  
Shireen Jahn Kassim ◽  
Alias Abdullah

This paper analyses the historical pre-Colonial configurations of a series of urban cores in Malay sites along the Straits of Melaka. The objective of this research is to identify the pattern and variations of each pre-Colonial royal urban core from the perspective of urban design principle such as “intimacy” and “walkability,” which can affect in a long term sustainable parameters such as the reduction of “urban heat island”. This traditional character is increasingly disappearing due to urbanisation. There is a difficulty to reconstruct the urban core of these case studies because of their past layouts’ degree of organic character, particularly in terms of randomness. This paper argues that such configurations reflect the degree of “intimacy,” which was ruptured during the Colonial eras. Patterns were identified using available maps and lithography related to the case studies. The findings indicate that the Malay royal urban core does obey the urban design principles of intimacy and walkability. The “intimacy indices” for a historical Malay city are as follow: distance from palace to mosque (170 metre), padang/open spaces (130 metre), settlement (310 metre), market (195 metre), and aristocrat houses (60 metre). This finding can be used to inform the baseline for the preparation of the Malay principles guidelines.


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