Aerosol optical depth retrieval over the city of Abu Dhabi, United Arab Emirates (UAE) using Landsat-8 OLI images

Aerosol is an essential parameter for assessing the atmospheric environmental quality, and accurate monitoring of the aerosol optical depth (AOD) is of great significance in climate research and environmental protection. Based on Landsat 8 Operational Land Imager (OLI) images and MODIS09A1 surface reflectance products under clear skies with limited cloud cover, we retrieved the AODs in Nanjing City from 2017 to 2018 using the combined Dark Target (DT) and Deep Blue (DB) methods. The retrieval accuracy was validated by in-situ CE-318 measurements and MOD04_3K aerosol products. Furthermore, we analyzed the spatiotemporal distribution of the AODs and discussed a case of high AOD distribution. The results showed that: (1) Validated by CE-318 and MOD04_3K data, the correlation coefficient (R), root mean square error (RMSE), and mean absolute error (MAE) of the retrieved AODs were 0.874 and 0.802, 0.134 and 0.188, and 0.099 and 0.138, respectively. Hence, the combined DT and DB algorithms used in this study exhibited a higher performance than the MOD04_3K-obtained aerosol products. (2) Under static and stable meteorological conditions, the average annual AOD in Nanjing was 0.47. At the spatial scale, the AODs showed relatively high values in the north and west, low in the south, and the lowest in the center. At the seasonal scale, the AODs were highest in the summer, followed by spring, winter, and autumn. Moreover, changes were significantly higher in the summer than in the other three seasons, with little differences among spring, autumn, and winter. (3) Based on the spatial and seasonal characteristics of the AOD distribution in Nanjing, a case of high AOD distribution caused by a large area of external pollution and local meteorological conditions was discussed, indicating that it could provide extra details of the AOD distribution to analyze air pollution sources using fine spatial resolution like in the Landsat 8 OLI.

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Aerosol Optical Depth Retrieval over Bright Areas Using Landsat 8 OLI Images

Remote Sensing ◽

10.3390/rs8010023 ◽

2015 ◽

Vol 8 (1) ◽

pp. 23 ◽

Cited By ~ 53

Author(s):

Lin Sun ◽

Jing Wei ◽

Muhammad Bilal ◽

Xinpeng Tian ◽

Chen Jia ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Landsat 8 ◽

Landsat 8 Oli

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Monitoring the Spatial Variation of Aerosol Optical Depth and Its Correlation with Land Use/Land Cover in Wuhan, China: A Perspective of Urban Planning

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031132 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1132

Author(s):

Qijiao Xie ◽

Qi Sun

Keyword(s):

Land Use ◽

Air Quality ◽

Urban Planning ◽

Land Cover ◽

Aerosol Optical Depth ◽

Optical Depth ◽

Water Bodies ◽

Landsat 8 ◽

Land Use Land Cover ◽

The Impact

Aerosols significantly affect environmental conditions, air quality, and public health locally, regionally, and globally. Examining the impact of land use/land cover (LULC) on aerosol optical depth (AOD) helps to understand how human activities influence air quality and develop suitable solutions. The Landsat 8 image and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products in summer in 2018 were used in LULC classification and AOD retrieval in this study. Spatial statistics and correlation analysis about the relationship between LULC and AOD were performed to examine the impact of LULC on AOD in summer in Wuhan, China. Results indicate that the AOD distribution expressed an obvious “basin effect” in urban development areas: higher AOD values concentrated in water bodies with lower terrain, which were surrounded by the high buildings or mountains with lower AOD values. The AOD values were negatively correlated with the vegetated areas while positively correlated to water bodies and construction lands. The impact of LULC on AOD varied with different contexts in all cases, showing a “context effect”. The regression correlations among the normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), normalized difference water index (NDWI), and AOD in given landscape contexts were much stronger than those throughout the whole study area. These findings provide sound evidence for urban planning, land use management and air quality improvement.

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Nine years of UV aerosol optical depth measurements at Thessaloniki, Greece

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-2091-2007 ◽

2007 ◽

Vol 7 (8) ◽

pp. 2091-2101 ◽

Cited By ~ 90

Author(s):

S. Kazadzis ◽

A. Bais ◽

V. Amiridis ◽

D. Balis ◽

C. Meleti ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Back Trajectories ◽

Air Masses ◽

North Eastern ◽

Range Transport ◽

Air Quality Monitoring Stations ◽

Pm 10 ◽

The City

Abstract. Spectral measurements of the aerosol optical depth (AOD) and the Ångström coefficient were conducted at Thessaloniki, Greece (40.5° N, 22.9° E) between January 1997 and December 2005 with a Brewer MKIII double-monochromator spectroradiometer. The dataset was compared with collocated measurements of a second spectroradiometer (Brewer MKII) and a CIMEL sun-photometer, showing correlations of 0.93 and 0.98, respectively. A seasonal variation of the AOD was observed at Thessaloniki, with AOD values at 340 nm of 0.52 and 0.28 for August and December respectively. Back trajectories of air masses for up to 4 days were used to assess the influence of long-range transport from various regions to the aerosol load over Thessaloniki. It is shown that part of the observed seasonality can be attributed to air masses with high AOD originating from North-Eastern and Eastern directions during summertime. The analysis of the long-term record (9 years) of AOD showed a downward tendency. A similar decreasing tendency was found in the record of the PM$_{10}$ aerosol measurements, which are conducted near the surface at 4 air-quality monitoring stations in the area of the city of Thessaloniki.

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Thermal Remote Sensing: A tool to Determine Temporal Land Surface Temperature in Hawassa City, Ethiopia

10.21203/rs.3.rs-63046/v1 ◽

2020 ◽

Author(s):

Mikias Biazen Molla

Keyword(s):

Remote Sensing ◽

Standard Deviation ◽

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Urban Expansion ◽

Landsat 8 ◽

Landsat 8 Oli ◽

Thermal Remote Sensing ◽

The City

Abstract This investigation was conducted for the estimation of the temporal land surface temperature value using thermal remote sensing of Landsat-8 (OLI) Data in Hawassa City Administration, Ethiopia. Satellite datasets of Landsat-7 (ETM+) for 22nd March 2002 and Landsat-8 (OLI) of 22nd March 2019 were taken for this study. Different algorisms were used to estimate the Normalized Difference Vegetation Index threshold from the Red and Near-Infrared band and the ground earth's surface emissivity esteem is legitimately recovered from the thermal infrared by coordinating with the outcome got from MODIS information. The land use land cover map of the city was prepared with better accuracy using the on-screen classification technique. The spatial distribution of surface temperature of the city range from 6.62°C to 22.54°C with a mean of 14.58°C and a standard deviation of 11.25 in the year of march 22nd 2002. The LST result derived from Landsat 8 for March 22nd, 2019, ranges from 11.97°C to 35.5°C with a mean of 23.735 °C and a standard deviation of 16.64. In both years the higher LST values correspond to built-up/settlement and bare/open lands of the city; whereas, lower LST values were observed in vegetation (trees/woodlot, shrubs, and grass forested) area. Urban expansion (built-up area roads, and another impervious surface), decline in vegetation levels due to deforestation and increasing population density. Increasing an evergreen tree and green space coverage, design and develop city parks and rehabilitate the existing degraded natural environments are among the recommended strategy to reduce the rate of LST.

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Land cover analysis using object based image analysis based on Landsat 8 OLI images in the city of Jember

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/747/1/012047 ◽

2021 ◽

Vol 747 (1) ◽

pp. 012047

Author(s):

E I Pangastuti ◽

Y Wijayanto

Keyword(s):

Image Analysis ◽

Land Cover ◽

Landsat 8 ◽

Landsat 8 Oli ◽

Object Based Image Analysis ◽

Object Based ◽

The City

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Caracterização detalhada das unidades de relevo do município de Jaguari (RS), Brasil / Detailed characterization of units relief in city of Jaguari (RS), Brazil

Caderno de Geografia ◽

10.5752/p.2318-2962.2016v26n46p404 ◽

2016 ◽

Vol 26 (46) ◽

pp. 404

Author(s):

Bruno Zucuni Prina ◽

Romario Trentin

Keyword(s):

System Modeling ◽

Spatial Location ◽

Landsat 8 ◽

Landsat 8 Oli ◽

Erosion Processes ◽

Topographic Attributes ◽

Methodological Procedures ◽

The City ◽

Methodological Paper

Nesse trabalho realizou-se um mapeamento das unidades de relevo no município de Jaguari/RS, com base na análise de atributos topográficos, entre eles, com destaque a hipsometria, a declividade, o plano de curvatura e o perfil de curvatura. O objetivo geral do trabalho é o de realizar o mapeamento das unidades de relevo na área de estudo e, posteriormente, identificar as características particulares e a localização espacial dessas unidades. Todos os procedimentos metodológicos foram realizados com a utilização do aplicativo ArcGIS®, junto a utilização de uma cena da imagem SRTM, bem como com uma imagem do Landsat 8 OLI e TIRS, ambas obtidas por meio do sítio do USGS. As rotinas metodológicas do trabalho podem ser sintetizadas com a análise da relação entre a distribuição das unidades de relevo com os distintos usos da terra (classificação digital realizada junto a imagem Landsat 8 OLI e TIRS). Ainda, verificou-se a tendência da área quanto a prováveis processos erosivos, assim sendo, cerca de 64% da área ficou englobada dentro de uma classificação de "alta tendência" a ocorrência de processos erosivos. Com a análise acerca da correlação entre uso da terra com as unidades de relevo, verificou-se que as áreas consideradas como de "alta tendência" a processos erosivos, estão dispostas, principalmente nos locais da superfície caracterizados como "solo exposto", maximizando o alerta à área no que se refere a prováveis futuros problemas quanto a perda de solo.Palavras-chaves: Sistema de Informações Geográficas, Modelagem, Geomorfologia, Jaguari/RS.AbstractIn the present paper was performed a mapping of relief units in the city of Jaguari/Brazil, based on the analysis topographic attributes, for example: the altimetry, slope, curvature plan and curvature profile. The general aim this paper is to perform the mapping of relief units in the study area and, thereafter, identify the characteristics and the spatial location these units. All the methodological procedures were performed using the ArcGIS®, and with a scene SRTM image, and with one image of Landsat 8 OLI and TIRS, both obtained through USGS site. The methodological paper routines can be synthesized with analysis of the interaction between distributions of relief units together with different land uses (digital classification conducted using image Landsat 8 OLI and TIRS). It should be noted that was further analyzed the tendency of the study area as the likely occurrence of erosion processes, therefore, was found 64% of the area is characterized with labeling of "high trend" the occurrence of erosion. Analyzing the data refers to correlation between land use with relief units, was observed that the areas considered as "high trend" the occurrence of erosion, are located, mainly the local surface classified as "exposed soil" increasing the concern in these area as regards probable future problems with the loss of soil (erosion).Keywords: Geographic Information System, Modeling, Geomorphology, Jaguari/RS

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Aerosol forcing efficiency in the UVA region from spectral solar irradiance measurements at an urban environment

Annales Geophysicae ◽

10.5194/angeo-27-2515-2009 ◽

2009 ◽

Vol 27 (6) ◽

pp. 2515-2522 ◽

Cited By ~ 29

Author(s):

S. Kazadzis ◽

N. Kouremeti ◽

A. Bais ◽

A. Kazantzidis ◽

C. Meleti

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Radiative Transfer Model ◽

Transfer Model ◽

Model Calculations ◽

Aerosol Forcing ◽

Aerosol Absorption ◽

Absorbing Aerosols ◽

Spectral Solar Irradiance ◽

The City

Abstract. Spectral Ultraviolet (UV) measurements using a Brewer MKIII double spectroradiometer were used for the determination of the aerosol forcing efficiency (RFE) under cloud free conditions at Thessaloniki, Greece for the period 1998–2006. Using measured spectral UVA irradiance in combination with synchronous aerosol optical depth (AOD) measurements at 340 nm, we calculated the seasonal and the percent RFE changes with the help of radiative transfer model calculations used for cloud and aerosol free conditions reference. The calculated RFE for the 325–340 nm wavelength integral was found to be −0.71±0.30 W m−2/τs340 nm and corresponds to a mean calculated RFE% value of −15.2%±3.8% (2 σ) per unit of τs340 nm, for the whole period. This indicates a mean reduction of 15.2% of the 325–340 nm irradiance for a unit of aerosol optical depth slant column increase. Lower RFE% was found during summertime, which is a possible indication of lower absorbing aerosols. Mean AOD slant at 340 nm for the city of Thessaloniki were processed in combination with RFE% and a mean monthly UVA attenuation of ~10% for the whole period was revealed. The nine years' analysis results showed a reduction in RFE%, which provides a possible indication of the changes in the optical properties over the city area. If such changes are only due to changes in the aerosol absorbing properties, the above finding suggests a 2% per decade increase in UVA due to changes in the aerosol absorption properties, in addition to the calculated increase by 4.2%, which is attributed only to AOD decrease at Thessaloniki area over the 1998–2006 period.

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