Retrieval of High Temporal Resolution Aerosol Optical Depth Using the GOCI Remote Sensing Data

High temporal resolution aerosol optical depth (AOD) products are very important for the studies of atmospheric environment and climate change. Geostationary Ocean Color Imager (GOCI) is a suitable data source for AOD retrieval, as it can monitor hourly aerosol changes and make up for the low temporal resolution deficiency of polar orbiting satellite. In this study, we proposed an algorithm for retrieving high temporal resolution AOD using GOCI data and then applied the algorithm in the Yangtze River Delta, a typical region suffering severe air pollution issues. Based on Moderate-resolution Imaging Spectroradiometer (MODIS) surface reflectance determined by MODIS V5.2 algorithm and MODIS Bidirectional Reflectance Distribution Function (BRDF) data, after spectral conversion between MODIS and GOCI, the GOCI surface reflectance at different solar angles were obtained and used to retrieve AOD. Five indicators including correlation coefficient (R), significant level of the correlation (p value), mean absolute error (MAE), mean relative error (MRE) and root mean square error (RMSE) were employed to analyze the errors between the Aerosol Robotic Network (AERONET) observed AOD and the GOCI retrieved AOD. The results showed that the GOCI AOD retrieved by the continental aerosol look-up table was consistent with the AERONET AOD (R > 0.7, p ≤ 0.05). The highest R value of Taihu Station and Xuzhou CUMT Station are both 0.84 (8:30 a.m.); the minimum RMSE at Taihu and Xuzhou-CUMT stations were 0.2077 (11:30 a.m.) and 0.1937 (10:30 a.m.), respectively. Moreover, the results suggested that the greater the solar angle of the GOCI sensor, the higher the AOD retrieval accuracy, while the retrieved AOD at noon exhibited the largest error as assessed by MAE and MRE. We concluded that the inaccurate estimation of surface reflectance was the root cause of the retrieval errors. This study has implications in providing a deep understanding of the effects of solar angle changes on retrieving AOD using GOCI.

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A multi-angle aerosol optical depth retrieval algorithm for geostationary satellite data over the United States

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-12519-2011 ◽

2011 ◽

Vol 11 (4) ◽

pp. 12519-12560

Author(s):

H. Zhang ◽

A. Lyapustin ◽

Y. Wang ◽

S. Kondragunta ◽

I. Laszlo ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Atmospheric Correction ◽

The United States ◽

Retrieval Algorithm ◽

High Temporal Resolution ◽

Surface Reflectance ◽

Western Us ◽

Moderate Resolution Imaging Spectroradiometer ◽

Polar Orbiting Satellite

Abstract. Aerosol optical depth (AOD) retrieval from geostationary satellites has high temporal resolution compared to the polar orbiting satellites and thus enables us to monitor aerosol motion. However, current Geostationary Operational Environmental Satellites (GOES) have only one visible channel for retrieving aerosol and hence the retrieval accuracy is lower than those from the multichannel polar-orbiting satellite instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS). The operational GOES AOD retrieval algorithm (GOES Aerosol/Smoke Product, GASP) uses 28-day composite images from the visible channel to derive surface reflectance, which can produce large uncertainties. In this work, we develop a new AOD retrieval algorithm for the GOES imager by applying a modified multi-angle Implementation of Atmospheric Correction (MAIAC) algorithm. The algorithm assumes the surface Bidirectional Reflectance Distribution Function (BRDF) at channel 1 of GOES is proportional to seasonal average BRDF in the 2.1 μm channel from MODIS. The ratios between them are derived through time series analysis of the GOES visible channel images. The results of the AOD and surface reflectance retrievals are evaluated through comparison against those from Aerosol Robotic Network (AERONET), GASP, and MODIS. The AOD retrievals from the new algorithm demonstrate good agreement with AERONET retrievals at several sites across the US. They are comparable to the GASP retrievals in the eastern-central sites and are more accurate than GASP retrievals in the western sites. In the western US where surface reflectance is high, the new algorithm also produces larger AOD retrieval coverage than both GASP and MODIS.

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A multi-angle aerosol optical depth retrieval algorithm for geostationary satellite data over the United States

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-11977-2011 ◽

2011 ◽

Vol 11 (23) ◽

pp. 11977-11991 ◽

Cited By ~ 27

Author(s):

H. Zhang ◽

A. Lyapustin ◽

Y. Wang ◽

S. Kondragunta ◽

I. Laszlo ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Atmospheric Correction ◽

Correlation Coefficients ◽

The United States ◽

Retrieval Algorithm ◽

High Temporal Resolution ◽

Surface Reflectance ◽

Moderate Resolution Imaging Spectroradiometer ◽

Polar Orbiting Satellite

Abstract. Aerosol optical depth (AOD) retrievals from geostationary satellites have high temporal resolution compared to the polar orbiting satellites and thus enable us to monitor aerosol motion. However, current Geostationary Operational Environmental Satellites (GOES) have only one visible channel for retrieving aerosols and hence the retrieval accuracy is lower than those from the multichannel polar-orbiting satellite instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS). The operational GOES AOD retrieval algorithm (GOES Aerosol/Smoke Product, GASP) uses 28-day composite images from the visible channel to derive surface reflectance, which can produce large uncertainties. In this work, we develop a new AOD retrieval algorithm for the GOES imager by applying a modified Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm. The algorithm assumes the surface Bidirectional Reflectance Distribution Function (BRDF) in the channel 1 of GOES is proportional to seasonal average MODIS BRDF in the 2.1 μm channel. The ratios between them are derived through time series analysis of the GOES visible channel images. The results of AOD and surface reflectance retrievals are evaluated through comparisons against those from Aerosol Robotic Network (AERONET), GASP, and MODIS. The AOD retrievals from the new algorithm demonstrate good agreement with AERONET retrievals at several sites across the US with correlation coefficients ranges from 0.71 to 0.85 at five out of six sites. At the two western sites Railroad Valley and UCSB, the MAIAC AOD retrievals have correlations of 0.8 and 0.85 with AERONET AOD, and are more accurate than GASP retrievals, which have correlations of 0.7 and 0.74 with AERONET AOD. At the three eastern sites, the correlations with AERONET AOD are from 0.71 to 0.81, comparable to the GASP retrievals. In the western US where surface reflectance is higher than 0.15, the new algorithm also produces larger AOD retrieval coverage than both GASP and MODIS.

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High temporal resolution estimates of columnar aerosol microphysical parameters from spectrum of aerosol optical depth by linear estimation: application to long-term AERONET and star-photometry measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-8-3117-2015 ◽

2015 ◽

Vol 8 (8) ◽

pp. 3117-3133 ◽

Cited By ~ 18

Author(s):

D. Pérez-Ramírez ◽

I. Veselovskii ◽

D. N. Whiteman ◽

A. Suvorina ◽

M. Korenskiy ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Temporal Resolution ◽

High Temporal Resolution ◽

Linear Estimation ◽

Night Time ◽

Microphysical Properties ◽

Fine Mode ◽

Using Data ◽

Aerosol Types

Abstract. This work deals with the applicability of the linear estimation technique (LE) to invert spectral measurements of aerosol optical depth (AOD) provided by AERONET CIMEL sun photometers. The inversion of particle properties using only direct-sun AODs allows the evaluation of parameters such as effective radius (reff) and columnar volume aerosol content (V) with significantly better temporal resolution than the operational AERONET algorithm which requires both direct sun and sky radiance measurements. Sensitivity studies performed demonstrate that the constraints on the range of the inversion are very important to minimize the uncertainties, and therefore estimates of reff can be obtained with uncertainties less than 30 % and of V with uncertainties below 40 %. The LE technique is applied to data acquired at five AERONET sites influenced by different aerosol types and the retrievals are compared with the results of the operational AERONET code. Good agreement between the two techniques is obtained when the fine mode predominates, while for coarse mode cases the LE results systematically underestimate both reff and V. The highest differences are found for cases where no mode predominates. To minimize these biases, correction functions are developed using the multi-year database of observations at selected sites, where the AERONET retrieval is used as the reference. The derived corrections are tested using data from 18 other AERONET stations offering a range of aerosol types. After correction, the LE retrievals provide better agreement with AERONET for all the sites considered. Finally, the LE approach developed here is applied to AERONET and star-photometry measurements in the city of Granada (Spain) to obtain day-to-night time evolution of columnar aerosol microphysical properties.

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Validation, comparison, and integration of GOCI, AHI, MODIS, MISR, and VIIRS aerosol optical depth over East Asia during the 2016 KORUS-AQ campaign

Atmospheric Measurement Techniques ◽

10.5194/amt-12-4619-2019 ◽

2019 ◽

Vol 12 (8) ◽

pp. 4619-4641 ◽

Cited By ~ 14

Author(s):

Myungje Choi ◽

Hyunkwang Lim ◽

Jhoon Kim ◽

Seoyoung Lee ◽

Thomas F. Eck ◽

...

Keyword(s):

Air Quality ◽

East Asia ◽

Aerosol Optical Depth ◽

Optical Depth ◽

Temporal Resolution ◽

High Accuracy ◽

The Yellow Sea ◽

High Temporal Resolution ◽

Earth Orbit ◽

Satellite Sensors

Abstract. Recently launched multichannel geostationary Earth orbit (GEO) satellite sensors, such as the Geostationary Ocean Color Imager (GOCI) and the Advanced Himawari Imager (AHI), provide aerosol products over East Asia with high accuracy, which enables the monitoring of rapid diurnal variations and the transboundary transport of aerosols. Most aerosol studies to date have used low Earth orbit (LEO) satellite sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging Spectroradiometer (MISR), with a maximum of one or two overpass daylight times per day from midlatitudes to low latitudes. Thus, the demand for new GEO observations with high temporal resolution and improved accuracy has been significant. In this study the latest versions of aerosol optical depth (AOD) products from three LEO sensors – MODIS (Dark Target, Deep Blue, and MAIAC), MISR, and the Visible/Infrared Imager Radiometer Suite (VIIRS), along with two GEO sensors (GOCI and AHI), are validated, compared, and integrated for a period during the Korea–United States Air Quality Study (KORUS-AQ) field campaign from 1 May to 12 June 2016 over East Asia. The AOD products analyzed here generally have high accuracy with high R (0.84–0.93) and low RMSE (0.12–0.17), but their error characteristics differ according to the use of several different surface-reflectance estimation methods. High-accuracy near-real-time GOCI and AHI measurements facilitate the detection of rapid AOD changes, such as smoke aerosol transport from Russia to Japan on 18–21 May 2016, heavy pollution transport from China to the Korean Peninsula on 25 May 2016, and local emission transport from the Seoul Metropolitan Area to the Yellow Sea in South Korea on 5 June 2016. These high-temporal-resolution GEO measurements result in more representative daily AOD values and make a greater contribution to a combined daily AOD product assembled by median value selection with a 0.5∘×0.5∘ grid resolution. The combined AOD is spatially continuous and has a greater number of pixels with high accuracy (fraction within expected error range of 0.61) than individual products. This study characterizes aerosol measurements from LEO and GEO satellites currently in operation over East Asia, and the results presented here can be used to evaluate satellite measurement bias and air quality models.

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Validation of JAXA Himawari-8 Aerosol Optical Depth Products over China with AERONET and CARSNET Observations

10.5194/egusphere-egu2020-18695 ◽

2020 ◽

Author(s):

Ling Gao ◽

Chengcai Li ◽

Lin Chen ◽

Jun Li ◽

Huizheng Che

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Southern China ◽

Correlation Coefficients ◽

Northern China ◽

Temporal Variations ◽

Retrieval Algorithm ◽

High Temporal Resolution ◽

Surface Reflectance ◽

Modis Aod

The performance of JAXA Himawari-8 Advanced Himawari Imager (AHI) aerosol optical depth (AOD) products over China is evaluated with ground-based AErosol&#160;RObotic&#160;NETwork (AERONET) and Sun-Sky Radiometer Observation Network (CARSNET) observations as well as the Moderate Resolution Imaging Spectroradiometer (MODIS) AOD products. Considering the quality and quantity of valid data, the study was limited to AOD products from AHI with a Quality Assurance Flag (QA_Flag) of &#8220;good&#8221; and &#8220;very good.&#8221; The spatial distribution of the AHI AOD product is similar to that of the MODIS AOD product. The AOD correlation between AHI and MODIS is better in the morning than in the afternoon after March, however, using MODIS AOD as a reference resulted in underestimation in the morning and overestimation in the afternoon. The bias is also larger in spring and autumn than in summer and winter. Validation with sun-photometer observations indicates good correlation between AHI AOD and ground-based observations with correlation coefficients larger than 0.75 (N>1000) when barren and sparsely vegetated surfaces are excluded. At 02:30 UTC, 53% of the collocated AHI AOD observations fall in the expected error (EE) range and at 5:30 UTC, 59.3% fall above the EE. The AHI AOD overestimation was apparent at the Northern China stations in April and after October, whereas the underestimation was apparent in southern China throughout the year. The temporal variations of AHI and AERONET AOD also show that the overestimation occurred in the afternoon and underestimation occurred in the morning.The assumption that the solar geometries were nearly identical and the surface reflectance unchanged for a month causes the surface reflectance underestimation and leads to the AOD overestimation for barren surfaces in autumn and winter. Because background aerosols were neglected, the surface reflectance was overestimated, leading to AOD underestimation in vegetated surfaces.Overall, the JAXA AOD provides a reliable and high temporal resolution aerosol product for environmental and climate research and the aerosol retrieval algorithm requires improvement.

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High temporal resolution estimates of columnar aerosol microphysical parameters from spectrum of aerosol optical depth by Linear Estimation: application to long-term AERONET and Star-photometry measurements

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-2331-2015 ◽

2015 ◽

Vol 8 (3) ◽

pp. 2331-2378

Author(s):

D. Pérez-Ramírez ◽

I. Veselovskii ◽

D. N. Whiteman ◽

A. Suvorina ◽

M. Korenskiy ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Temporal Resolution ◽

High Temporal Resolution ◽

Linear Estimation ◽

Night Time ◽

Microphysical Properties ◽

Fine Mode ◽

Using Data ◽

Aerosol Types

Abstract. This work deals with the applicability of the Linear Estimation technique (LE) to invert spectral measurements of aerosol optical depth (AOD) provided by AERONET CIMEL sun-photometers. The inversion of particle properties using only direct sun AODs allows the evaluation of parameters such as effective radius (reff) and columnar volume aerosol content (V) with significantly better temporal resolution than the operational AERONET algorithm which requires both direct sun and sky radiance measurements. Sensitivity studies performed demonstrate that the constraints on the range of the inversion are very important to minimize the uncertainties, and therefore estimates of reff can be obtained with uncertainties less than 30% and of V with uncertainties below 40%. The LE technique is applied to data acquired at five AERONET sites influenced by different aerosol types and the retrievals are compared with the results of the operational AERONET code. Good agreement between the two techniques is obtained when the fine mode predominates, while for coarse mode cases the LE results systematically underestimate both reff and V. The highest differences are found for cases where no mode predominates. To minimize these biases, correction functions are developed using the multi-year database of observations at selected sites, where the AERONET retrieval is used as the reference. The derived corrections are tested using data from 18 other AERONET stations offering a range of aerosol types. After correction, the LE retrievals provide better agreement with AERONET for all the sites considered. Finally, the LE approach developed here is applied to AERONET and star-photometry measurements at the city of Granada (Spain) to obtain day-to-night time-evolution of columnar aerosol microphysical properties.

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Validation, comparison, and integration of GOCI, AHI, MODIS, MISR, and VIIRS aerosol optical depth over East Asia during the 2016 KORUS-AQ campaign

10.5194/amt-2019-46 ◽

2019 ◽

Cited By ~ 1

Author(s):

Myungje Choi ◽

Hyunkwang Lim ◽

Jhoon Kim ◽

Seoyoung Lee ◽

Thomas F. Eck ◽

...

Keyword(s):

Air Quality ◽

East Asia ◽

Aerosol Optical Depth ◽

Optical Depth ◽

Temporal Resolution ◽

High Accuracy ◽

The Yellow Sea ◽

High Temporal Resolution ◽

Earth Orbit ◽

Satellite Sensors

Abstract. Recently launched multi-channel geostationary-Earth-orbit (GEO) satellite sensors such as the Geostationary Ocean Color Imager (GOCI) and the Advanced Himawari Imager (AHI) provide aerosol products over East Asia with high accuracy, which enables the monitoring of rapid diurnal variations and the transboundary transport of aerosols. Most aerosol studies to date have used low-Earth-orbit (LEO) satellite sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging SpectroRadiometer (MISR) with a maximum of one or two overpass daylight times per day at mid- to low latitudes. Thus, the demand for new GEO observations with high temporal resolution and improved accuracy has been significant. In this study the aerosol optical depth (AOD) products from three LEO sensors – MODIS, MISR, and the Visible/Infrared Imager Radiometer Suite (VIIRS) – along with two GEO sensors – GOCI and AHI – are validated, compared and integrated for the period during the Korea–United Sates Air Quality Study (KORUS-AQ) field campaign from 1 May to 12 June 2016 over East Asia. The AOD products analyzed here generally have high accuracy, but their error characteristics differ according to the use of several different surface-reflectance estimation methods plus differences in cloud screening. High-accuracy near-real-time GOCI and AHI measurements facilitate the detection of rapid AOD changes, such as smoke aerosol transport from Russia to Japan on 18–21 May 2016, heavy pollution transport from China to Korea on 25 May 2016, and local emission transport from the Seoul Metropolitan Area to the Yellow Sea in Korea on 5 June 2016. These high-temporal-resolution GEO measurements result in more-representative daily AOD values and make a greater contribution to a combined daily AOD product assembled by median-value selection with a 0.5° × 0.5° grid resolution. The combined AOD is more spatially continuous and of higher accuracy than the individual products. This study characterizes aerosol measurements from LEO and GEO satellites currently in operation over East Asia, and results presented here can be used to evaluate satellite measurement bias and air-quality models.

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Harmonized and high-quality datasets of aerosol optical depth at a US continental site, 1997–2018

Scientific Data ◽

10.1038/s41597-021-00866-2 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Evgueni Kassianov ◽

Erol Cromwell ◽

Justin Monroe ◽

Laura D. Riihimaki ◽

Connor Flynn ◽

...

Keyword(s):

Aerosol Optical Depth ◽

Optical Depth ◽

Temporal Resolution ◽

Wavelength Dependence ◽

High Temporal Resolution ◽

High Quality ◽

Wide Range ◽

Climate Change Assessment ◽

The Individual

AbstractAerosol optical depth (AOD) characterizes the aerosol burden in the atmosphere, while its wavelength dependence is a sign of particle size. Long-term records of wavelength-resolved AOD with high quality and suitable continuity are required for climate change assessment. Typically, climate-related studies use AOD products provided by several, and perhaps different, ground-based instruments. The measurements from these instruments often have different accuracy and temporal resolution. To preserve the advantages of these products (high quality) and to reduce their disadvantages (patchy records), we generate a merged dataset obtained from four instruments deployed at a US continental site in which a nearly-continuous AOD record is found at two wavelengths (500 and 870 nm) with high quality and high temporal resolution (1-min) for a 21-yr period (1997–2018). The combined dataset addresses: (1) varying data quality and resolution mismatch of the individual AOD records, and (2) the uncertainty of the merged AOD and its relevance for user-specified needs. The generated dataset will be beneficial for a wide range of applications including aerosol-radiation interactions.

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