Comparisons of spectral aerosol single scattering albedo  in Seoul, South Korea

Mok, Jungbin; Krotkov, Nickolay A.; Torres, Omar; Jethva, Hiren; Li, Zhanqing; Kim, Jhoon; Koo, Ja Ho; Go, Sujung; Irie, Hitoshi; Labow, G. J.; Eck, T. F.; Holben, B. N.; Herman, J. R.; Loughman, Robert; Spinei, E.; Lee, Seoung Soo; Khatri, Pradeep; Campanelli, Monica

doi:10.5194/amt-11-2295-2018

Cited by 40 publications

(35 citation statements)

References 85 publications

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“…As has been thoroughly discussed in previous studies [56,58,144], changes in aerosols were responsible for a large part of the long-term changes in the UV irradiance over both sites. In urban environments, absorption in the UV-B region can be much stronger than the absorption in the UV-A [147,158], which could lead to more significant increase of the irradiance at UV-B wavelengths when aerosol load decreases. This behavior is associated with the presence of brown carbon in the urban aerosol mixture [159][160][161].…”

Section: Update For Four Historical European Stationsmentioning

confidence: 99%

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

et al. 2019

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Review of the existing bibliography shows that the direction and magnitude of the long-term trends of UV irradiance, and their main drivers, vary significantly throughout Europe. Analysis of total ozone and spectral UV data recorded at four European stations during 1996–2017 reveals that long-term changes in UV are mainly driven by changes in aerosols, cloudiness, and surface albedo, while changes in total ozone play a less significant role. The variability of UV irradiance is large throughout Italy due to the complex topography and large latitudinal extension of the country. Analysis of the spectral UV records of the urban site of Rome, and the alpine site of Aosta reveals that differences between the two sites follow the annual cycle of the differences in cloudiness and surface albedo. Comparisons between the noon UV index measured at the ground at the same stations and the corresponding estimates from the Deutscher Wetterdienst (DWD) forecast model and the ozone monitoring instrument (OMI)/Aura observations reveal differences of up to 6 units between individual measurements, which are likely due to the different spatial resolution of the different datasets, and average differences of 0.5–1 unit, possibly related to the use of climatological surface albedo and aerosol optical properties in the retrieval algorithms.

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Section: Update For Four Historical European Stationsmentioning

confidence: 99%

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

et al. 2019

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“…The international network for aerosol, clouds, and solar radiation studies and their applications (SKYNET) [22,23] also retrieves SSA at visible wavelengths. Meanwhile, recent efforts have been made to also provide SSA at 340 and 380 nm, though it seems to systematically underestimate compared to UVMFR retrieved SSA, which is linked to the use of very high surface albedo value (0.1) in the current algorithm [20]. Still, datasets of SSA in the UV spectral region retrieved from ground-based measurements are not frequent and usually are available for short periods of time, whilst in scientific literature there are a few publications on the subject [4,7,8,20,[24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

“…Meanwhile, recent efforts have been made to also provide SSA at 340 and 380 nm, though it seems to systematically underestimate compared to UVMFR retrieved SSA, which is linked to the use of very high surface albedo value (0.1) in the current algorithm [20]. Still, datasets of SSA in the UV spectral region retrieved from ground-based measurements are not frequent and usually are available for short periods of time, whilst in scientific literature there are a few publications on the subject [4,7,8,20,[24][25][26][27]. UVMFR measurements are used in some of the above studies to retrieve SSA in UV wavelengths following the methodology as described in Kroktov et al [25,26].…”

Section: Introductionmentioning

confidence: 99%

“…These profiles of the extinction coefficient can be retrieved by airborne in situ vertical profiling of aerosols [16][17][18] but this approach remains very expensive and is rarely used in experimental campaigns. More commonly, retrievals of the mean columnar SSA from sun-photometric instruments are used to scale default climatological profiles used for RTM simulations [19] Measurements of the mean columnar SSA are available from a large number of sites around the globe, though rarely in the UV [8,20].…”

Section: Introductionmentioning

confidence: 99%

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Single Scattering Albedo’s Spectral Dependence Effect on UV Irradiance

et al. 2018

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The absorbing and scattering nature of aerosols affects the total radiative forcing and is quantified by single scattering albedo (SSA), which is defined as the absorption to total extinction ratio. There are limited measurements of SSA in the ultraviolet (UV) irradiance spectrum, hence, the influence of SSA on incoming UV irradiance has not been explored in great depth. In the present study, UV irradiance was calculated and compared using different SSA datasets retrieved at Athens, Greece during 2009–2014; including SSA time series from Ultraviolet Multi-Filter Radiometer (UVMFR) at 332 and 368 nm, SSA from AERONET at 440 nm, from OMI satellite at 342.5 nm and AeroCom climatological database at 300 nm. Irradiances were estimated using a radiative transfer model (RTM). Comparisons of these results revealed that relative differences of UVA and UVB could be as high as 20%, whilst average relative differences varied from 2% to 8.7% for the entire experimental period. Both UVA and UVB drop by a rate of ~12% for 0.05 aerosol absorption optical depth in comparison to ones estimated with the use of SSA at visible range. Brewer irradiance measurements at 324 nm were used to validate modeled monochromatic irradiances and a better agreement was found when UVMFR SSAs were used with an average difference of 0.86%. However, when using visible or climatological input, relative differences were estimated +4.91% and +4.15% accordingly.

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“…The k f has critical importance for monitoring the role of carbonaceous aerosols in tropospheric photochemistry and air quality (e.g., Castro et al, 2001;Dickerson et al, 1997;He & Carmichael, 1999). Particularly, absorbing components of organic aerosols (or sometimes called as brown carbon) have significant light absorption efficiency in the UV with strong wavelength dependence, which result in high UV absorption compared to visible or infrared wavelengths in various field and laboratory measurements (e.g., Chen & Bond, 2010;Kirchstetter et al, 2004;Martins et al, 2009;Mok et al, 2016Mok et al, , 2018Saleh et al, 2013;Zhong & Jang, 2014). Mok et al (2016) retrieved spectral ω 0 from UV to near infrared using combined data set from AERONET, MFRSR, and Pandora and quantified effects of the brown carbon on ozone photochemistry in the Amazon Basin.…”

Section: 1029/2019jd032088mentioning

confidence: 99%

The SMART‐s Trace Gas and Aerosol Inversions: I. Algorithm Theoretical Basis for Column Property Retrievals

et al. 2020

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The SMART‐s (Spectral Measurements for Atmospheric Radiative Transfer—spectroradiometer) acquires Sun/sky observations for retrieving optimal information on trace gases and aerosols with minimal assumptions. Overall, the algorithm of SMART‐s incorporates a series of retrievals, from fundamental quantities (i.e., column abundance of trace gases and aerosol loading) to higher‐order geophysical parameters (e.g., aerosol physicochemical properties and vertical profiles), utilizing Sun/sky spectral radiance measurements. This paper describes the theoretical basis for column retrievals of trace gases and aerosols. Associated profile retrievals will be presented in follow‐up papers. The current algorithm retrieves the fine/coarse mode of the particle size distribution and spectral complex index of refraction and, thereby, the spectral aerosol single‐scattering albedo ω0. SMART‐s retrieval is unique particularly in its high spectral resolution of the complex index of refraction and ω0 from near‐ultraviolet to near‐infrared wavelengths, which is pivotal information for atmospheric chemistry, climate and other inversions. We theoretically assessed information content and retrieval accuracy of the algorithm and compared different type of measurements including the Aerosol Robotic Network (AERONET) and standard Pandora. For the same levels of radiometric accuracy, SMART‐s measurements provide the most informative aerosol retrievals based on theoretical error analyses. Higher spectral resolution measurements are particularly beneficial for particle size distribution and fine‐mode refractive index retrievals. We applied this algorithm to the AERONET Sun/sky measurements at Kanpur, India, in 2016 to assess algorithm consistency. Even with different assumptions and numerical methods for the inversion, SMART‐s retrieved aerosol parameters agreed well with the AERONET operational products (e.g., absolute mean bias errors less than 0.01 for ω0).

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Comparisons of spectral aerosol single scattering albedo in Seoul, South Korea

Cited by 40 publications

References 85 publications

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

Single Scattering Albedo’s Spectral Dependence Effect on UV Irradiance

The SMART‐s Trace Gas and Aerosol Inversions: I. Algorithm Theoretical Basis for Column Property Retrievals

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