Horizontal distribution of temperature in a building-block using a Mobile Cart for Meteorological Observation (MCMO)

<p>Horizontal distribution of building block scale meteorological information is important to understand the disastrous weather phenomena occurred at urban areas. Most meteorological models assume the same surface temperature, or an ideal surface temperature to simulate the high-resolution wind field in or above urban boundary-layer. This study aims to establish the basic foundation for producing the high-resolution and high-quality user-specific horizontal meteorological information at an urban building block in the Seoul Metropolitan Area. Therefore, the Mobile Cart for Meteorological Observation (MCMO) was developed and used in a meteorological experimental campaign during heat wave event days.<br>The MCMO includes 3 air temperature sensors, 1 weather transmitter, 1 infrared surface temperature sensor, 1 GPS (global positioning system), and video camera on the mobile cart. The MCMO measures the temperature at 4 altitudes (surface, 0.5m, 1.5m, and 2.5m), latitude, longitude, and surrounding environment condition of measurement site. The observation cycle is 1 second to produce pedestrian-friendly weather information. The meteorological experimental campaign was conducted in Gwanghwamun square in the Seoul, Korea. Gwanghwamun square is complex area which has high-rise building block, wide roads of heavy traffic, and green lung. Observation period was from 1200 LST 5 August 2019 to 2200 LST 6 August 2019 including the hottest day of the year. Through the meteorological experimental campaign, the MCMO shows the detail temperature change over time, location, and altitudes. The temperature was changed as the altitude of the sun changed. When the MCMO was move through the green lung or building block, also the temperature was changed. Temperature changes were the largest at surface temperature and tended to decrease as altitude increased. The MCMO can be used to understand high-resolution weather information and horizontal distribution of temperature in urban area. Additionally, another meteorological experimental campaign will be held in the summer of 2020.</p>

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Downscaling Aster Land Surface Temperature over Urban Areas with Machine Learning-Based Area-To-Point Regression Kriging

Remote Sensing ◽

10.3390/rs12071082 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1082 ◽

Cited By ~ 3

Author(s):

Jianhui Xu ◽

Feifei Zhang ◽

Hao Jiang ◽

Hongda Hu ◽

Kaiwen Zhong ◽

...

Keyword(s):

Machine Learning ◽

High Resolution ◽

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Urban Areas ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Thermal Emission ◽

Independent Variables

Land surface temperature (LST) is a vital physical parameter of earth surface system. Estimating high-resolution LST precisely is essential to understand heat change processes in urban environments. Existing LST products with coarse spatial resolution retrieved from satellite-based thermal infrared imagery have limited use in the detailed study of surface energy balance, evapotranspiration, and climatic change at the urban spatial scale. Downscaling LST is a practicable approach to obtain high accuracy and high-resolution LST. In this study, a machine learning-based geostatistical downscaling method (RFATPK) is proposed for downscaling LST which integrates the advantages of random forests and area-to-point Kriging methods. The RFATPK was performed to downscale the 90 m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) LST 10 m over two representative areas in Guangzhou, China. The 10 m multi-type independent variables derived from the Sentinel-2A imagery on 1 November 2017, were incorporated into the RFATPK, which considered the nonlinear relationship between LST and independent variables and the scale effect of the regression residual LST. The downscaled results were further compared with the results obtained from the normalized difference vegetation index (NDVI) based thermal sharpening method (TsHARP). The experimental results showed that the RFATPK produced 10 m LST with higher accuracy than the TsHARP; the TsHARP showed poor performance when downscaling LST in the built-up and water regions because NDVI is a poor indicator for impervious surfaces and water bodies; the RFATPK captured LST difference over different land coverage patterns and produced the spatial details of downscaled LST on heterogeneous regions. More accurate LST data has wide applications in meteorological, hydrological, and ecological research and urban heat island monitoring.

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SPATIOTEMPORAL FUSION OF HIGH RESOLUTION LAND SURFACE TEMPERATURE USING THERMAL SHARPENED IMAGES FROM REGRESSION-BASED URBAN INDICES

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-v-3-2020-247-2020 ◽

2020 ◽

Vol V-3-2020 ◽

pp. 247-254

Author(s):

M. Kim ◽

K. Cho ◽

H. Kim ◽

Y. Kim

Keyword(s):

High Resolution ◽

Surface Temperature ◽

Brightness Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Urban Areas ◽

Absolute Difference ◽

Landsat 8 ◽

Thermal Images ◽

Urban Regions

Abstract. Obtaining spatially continuous, high resolution thermal images is crucial in order to effectively analyze heat-related phenomena in urban areas and the inherent high spatial and temporal variations. Spatiotemporal Fusion (STF) methods can be applied to enhance spatial and temporal resolutions simultaneously, but most STF approaches for the generation of Land Surface Temperature (LST) have not focused specifically on urban regions. This study therefore proposes a two-phase approach using Landsat 8 and MODIS images acquired on a study area in Beijing to first, investigate the sharpening of the fine resolution image input with urban-related spectral indices and second, to explore the potential of implementing the sharpened results into the Spatiotemporal Adaptive Data Fusion Algorithm for Temperature Mapping (SADFAT) to generate high spatiotemporal resolution LST images in urban areas. For this test, five urban indices were selected based on their correlation with brightness temperature. In the thermal sharpening phase, the Fractional Urban Cover (FUC) index was able to delineate spatial details in urban regions whilst maintaining its correlation with the original brightness temperature image. In the STF phase however, FUC sharpened results returned relatively high levels of correlation coefficient values up to 0.689, but suffered from the highest Root Mean Squared Error (RMSE) and Average Absolute Difference (AAD) values of 4.260 K and 2.928 K, respectively. In contrast, Normalized Difference Building Index (NDBI) sharpened results recorded the lowest RMSE and AAD values of 3.126 K and 2.325 K, but also the lowest CC values. However, STF results were effective in delineating fine spatial details, ultimately demonstrating the potential of using sharpened urban or built-up indices as a means to generate sharpened thermal images for urban areas, as well as for input images in the SADFAT algorithm. The results from this study can be used to further improve STF approaches for daily and spatially continuous mapping of LST in urban areas.

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Impact of COVID-19-Related Traffic Slowdown on Urban Heat Characteristics

Atmosphere ◽

10.3390/atmos12020243 ◽

2021 ◽

Vol 12 (2) ◽

pp. 243

Author(s):

Bernardo Teufel ◽

Laxmi Sushama ◽

Vincent Poitras ◽

Tarek Dukhan ◽

Stéphane Bélair ◽

...

Keyword(s):

Heat Stress ◽

Surface Temperature ◽

Urban Areas ◽

Heavy Traffic ◽

Urban Climate ◽

Surface Wind ◽

Warm Season ◽

Well Being ◽

Urban Centre ◽

Near Surface

Governments around the world have implemented measures to slow down the spread of COVID-19, resulting in a substantial decrease in the usage of motorized transportation. The ensuing decrease in the emission of traffic-related heat and pollutants is expected to impact the environment through various pathways, especially near urban areas, where there is a higher concentration of traffic. In this study, we perform high-resolution urban climate simulations to assess the direct impact of the decrease in traffic-related heat emissions due to COVID-19 on urban temperature characteristics. One simulation spans the January–May 2020 period; two additional simulations spanning the April 2019–May 2020 period, with normal and reduced traffic, are used to assess the impacts throughout the year. These simulations are performed for the city of Montreal, the second largest urban centre in Canada. The mechanisms and main findings of this study are likely to be applicable to most large urban centres around the globe. The results show that an 80% reduction in traffic results in a decrease of up to 1 °C in the near-surface temperature for regions with heavy traffic. The magnitude of the temperature decrease varies substantially with the diurnal traffic cycle and also from day to day, being greatest when the near-surface wind speeds are low and there is a temperature inversion in the surface layer. This reduction in near-surface temperature is reflected by an up to 20% reduction in hot hours (when temperature exceeds 30 °C) during the warm season, thus reducing heat stress for vulnerable populations. No substantial changes occur outside of traffic corridors, indicating that potential reductions in traffic would need to be supplemented by additional measures to reduce urban temperatures and associated heat stress, especially in a warming climate, to ensure human health and well-being.

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A Building-Block Urban Meteorological Observation Experiment (BBMEX) Campaign in Central Commercial Area in Seoul

Atmosphere ◽

10.3390/atmos11030299 ◽

2020 ◽

Vol 11 (3) ◽

pp. 299

Author(s):

Moon-Soo Park ◽

Jae-Young Byon ◽

Baek-Jo Kim ◽

Woosuk Choi ◽

Kwang-Min Myung ◽

...

Keyword(s):

High Resolution ◽

Surface Temperature ◽

Building Blocks ◽

Meteorological Observation ◽

Night Time ◽

3 Dimensional ◽

High Rise ◽

Air Temperatures ◽

Commercial Area ◽

Wave Event

High-resolution meteorological information is essential for attaining sustainable and resilient cities. To elucidate high-resolution features of surface and air temperatures in high-rise building blocks (BBs), a 3-dimensional BB meteorological observation experiment (BBMEX) campaign was designed. The campaign was carried out in a central commercial area in Seoul during a heat-wave event period (5−6 August) in 2019. Several types of fixed instrument were deployed, a mobile meteorological observation cart (MOCA) and a vehicle were operated periodically. The surface temperature was determined to be strongly dependent on the facial direction of a building, and sunlit or shade by surrounding obstacles. Considerable increases in surface temperature on the eastern facades of buildings before noon, on horizontal surfaces near noon, and on the western facades in the afternoon could provide more energy in BBs than over a flat surface. The air temperatures in the BB were higher than those at the Seoul station by 0.1−2.2 °C (1.1−1.9 °C) in daytime (night-time). The MOCA revealed that the surface and air temperatures in a BB could be affected by many complex factors, such as the structure of the BBs, shades, as well as the existence of facilities that mitigate heat stresses, such as ground fountains and waterways.

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High-Resolution Urban Observation Network for a User-Specific Meteorological Information Service in the Seoul Metropolitan Area, Korea

10.5194/amt-2016-278 ◽

2016 ◽

Author(s):

Moon-Soo Park ◽

Sung-Hwa Park ◽

Jung-Hoon Chae ◽

Min-Hyeok Choi ◽

Yunyoung Song ◽

...

Keyword(s):

Boundary Layer ◽

High Resolution ◽

Surface Energy Balance ◽

Information Service ◽

Meteorological Observation ◽

Weather Information ◽

Seoul Metropolitan Area ◽

Observation Network ◽

Quality Check ◽

Meteorological Models

Abstract. To improve our knowledge of urban meteorology, including those processes applicable to high-resolution meteorological models in the Seoul Metropolitan Area, a Weather Information Service Engine urban meteorological observation system network (UMS-Seoul) has been designed and installed. The network incorporates 14 surface energy balance (EB) systems, 7 surface-based 3-dimensional meteorological observation (3D) systems, and applied meteorological observation (AP) systems, as well as the existing surface-based meteorological observation network. The EB system consists of a radiation balance system, sonic anemometers, infrared CO2/H2O gas analyzers, and many sensors to measure wind speed and direction, temperature and humidity, precipitation, and air pressure, etc. The EB-produced radiation, meteorological, and turbulence data will be used to quantify the surface energy balance according to land use, and improve the boundary layer and surface processes in meteorological models. The 3D system, composed of wind lidar, a microwave radiometer, an aerosol lidar, or a ceilometer, produces vertical profiles of backscatter by aerosols or water vapor, cloud height, wind speed and direction, temperature, humidity, and liquid water content. It will be used for high-resolution reanalysis data based on observations as well as for improvement of the boundary layer, radiation, and microphysics processes in meteorological models. The AP system includes road weather information, mosquito activity, and water quality observation instruments. The standardized metadata for networks and stations are documented and renewed periodically to provide a detailed observation environment. The UMS-Seoul data are designed to support real-time acquisition, as well as display and automatically quality check the data within 10 minutes of observation. After the quality check, data can be distributed to relevant potential users such as researchers and policy makers.

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High-resolution urban observation network for user-specific meteorological information service in the Seoul Metropolitan Area, South Korea

Atmospheric Measurement Techniques ◽

10.5194/amt-10-1575-2017 ◽

2017 ◽

Vol 10 (4) ◽

pp. 1575-1594 ◽

Cited By ~ 19

Author(s):

Moon-Soo Park ◽

Sung-Hwa Park ◽

Jung-Hoon Chae ◽

Min-Hyeok Choi ◽

Yunyoung Song ◽

...

Keyword(s):

Boundary Layer ◽

High Resolution ◽

Information Service ◽

Meteorological Observation ◽

Weather Information ◽

Seoul Metropolitan Area ◽

Observation Network ◽

Observation Systems ◽

Quality Check ◽

Meteorological Models

Abstract. To improve our knowledge of urban meteorology, including those processes applicable to high-resolution meteorological models in the Seoul Metropolitan Area (SMA), the Weather Information Service Engine (WISE) Urban Meteorological Observation System (UMS-Seoul) has been designed and installed. The UMS-Seoul incorporates 14 surface energy balance (EB) systems, 7 surface-based three-dimensional (3-D) meteorological observation systems and applied meteorological (AP) observation systems, and the existing surface-based meteorological observation network. The EB system consists of a radiation balance system, sonic anemometers, infrared CO2/H2O gas analyzers, and many sensors measuring the wind speed and direction, temperature and humidity, precipitation, and air pressure. The EB-produced radiation, meteorological, and turbulence data will be used to quantify the surface EB according to land use and to improve the boundary-layer and surface processes in meteorological models. The 3-D system, composed of a wind lidar, microwave radiometer, aerosol lidar, or ceilometer, produces the cloud height, vertical profiles of backscatter by aerosols, wind speed and direction, temperature, humidity, and liquid water content. It will be used for high-resolution reanalysis data based on observations and for the improvement of the boundary-layer, radiation, and microphysics processes in meteorological models. The AP system includes road weather information, mosquito activity, water quality, and agrometeorological observation instruments. The standardized metadata for networks and stations are documented and renewed periodically to provide a detailed observation environment. The UMS-Seoul data are designed to support real-time acquisition and display and automatically quality check within 10 min from observation. After the quality check, data can be distributed to relevant potential users such as researchers and policy makers. Finally, two case studies demonstrate that the observed data have a great potential to help to understand the boundary-layer structures more deeply, improve the performance of high-resolution meteorological models, and provide useful information customized based on the user demands in the SMA.

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The importance of changing urban scenery in the assessment of citizens’ soundscape perception. On the need for different time-related points of view

Noise Mapping ◽

10.1515/noise-2021-0011 ◽

2021 ◽

Vol 8 (1) ◽

pp. 138-161

Author(s):

Jerónimo Vida Manzano ◽

José Antonio Almagro Pastor ◽

Rafael García Quesada

Keyword(s):

Urban Areas ◽

Noise Exposure ◽

Noise Control ◽

Action Plan ◽

Heavy Traffic ◽

Legal Protection ◽

Complementary Method ◽

Reduction Strategies ◽

The Right ◽

The City

Abstract The city of Granada is experimenting a big urban transformation, attending national and international commitments on clean air, energy efficiency and savings linked to greenhouse gases reduction strategies and sustainable development action plans. This situation constitutes a good scenario for new noise control approaches that take into account the sound variable and citizens empowering in urban design, such as the soundscape assessment of urban territory. In this way, soundscape tools have been used in Granada as a complementary method for environmental noise characterisation where traditional noise control techniques are difficult to be carried out or give limited results. After 2016 strategic noise map and in the preparation of the new noise action plan, the city came across a great acoustic challenge in a new area located outskirts characterised by growing urbanisation, still under development, the greatest legal protection because of sensitive teaching and hospital buildings and the greatest noise exposure from nearby ring-way supporting heavy traffic flow. As quiet urban areas are not characterised by the absence of noise but for the presence of the right noise, this research intended to provide the local administration with results and proposals to transform this conflict area in a pleasant or quiet urban place. Main results came from important and significative differences in morning and evening characterisation, as great differences appear in soundscape assessment over the day and along the soundwalk path, indicating the importance of time and local issues to adequately characterised citizens perception to be considered by administration in the development of strategies and effective noise control actions.

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