scholarly journals Long-term Variation of Absorption and Total Aerosol Optical Properties over Typical Provinces of China from Satellite Observations

2022 ◽  
Vol 2152 (1) ◽  
pp. 012001
Author(s):  
Heng Li
Keyword(s):  
Optical Properties ◽  
Atmospheric Aerosols ◽  
Guangdong Province ◽  
Shandong Province ◽  
Gansu Province ◽  
Monthly Variation ◽  
Aerosol Optical Properties ◽  
Aerosol Emission ◽  
Earth’S Climate

Abstract Increase of atmospheric aerosols has a profound impact on the Earth’s climate. It’s also one of the crucial factors that cuasesd more fequent air pollution events in China. Monthly average Aerosol Optical Depth (AOD) from MODIS and UltraViolet Absorbing aerosol Index (UVAI) from OMI during 2011 to 2019 are used to analyse the trend of absorption and total aerosol optical properties over three typical provinces of China, namely Shandong, Gansu and Guangdong provinces. The results show the average annual AOD of the three provinces are all decreasing while UVAI rises during this period. In addition, the monthly variation of AOD and UVAI are also obviously different over these provinces. In particular, the peak value of AOD appeared in July and the trough appeared in December over Shandong Province. And the peak appeared in April over Gansu Province, but AOD decrease slower then over Shandong Province. And there were two peaks in April and August over Guangdong Province. For UVAI, the peaks over Shandong and Gansu provinces both occur in January, while that over Guangdong Province appears in March. Above mentioned differences in the long-term trend and monthly variation of AOD and UVAI might be closely related to the meteorological conditions and aerosol emission of these three provinces.

Long-term observations of aerosol optical properties at three GAW regional sites in the Central Mediterranean

2020 ◽  
Vol 241 ◽  
pp. 104976 ◽  
Author(s):  
Antonio Donateo ◽  
Teresa Lo Feudo ◽  
Angela Marinoni ◽  
Claudia Roberta Calidonna ◽  
Daniele Contini ◽  
...  
Keyword(s):  
Optical Properties ◽  
Aerosol Optical Properties ◽  
Central Mediterranean

Aerosol optical properties at urban and coastal sites in Shandong Province, Northern China

2017 ◽  
Vol 188 ◽  
pp. 39-47 ◽  
Author(s):  
Weida Yan ◽  
Lingxiao Yang ◽  
Jianmin Chen ◽  
Xinfeng Wang ◽  
Liang Wen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Northern China ◽  
Shandong Province ◽  
Aerosol Optical Properties

scholarly journals An assessment of aerosol optical properties from remote-sensing observations and regional chemistry–climate coupled models over Europe

2018 ◽  
Vol 18 (7) ◽  
pp. 5021-5043 ◽  
Author(s):  
Laura Palacios-Peña ◽  
Rocío Baró ◽  
Alexander Baklanov ◽  
Alessandra Balzarini ◽  
Dominik Brunner ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Atmospheric Aerosols ◽  
Climate Models ◽  
Regional Climate ◽  
Chemical Properties ◽  
Remote Sensing Data ◽  
Regional Climate Models ◽  
Aerosol Optical Properties ◽  
Coupled Models

Abstract. Atmospheric aerosols modify the radiative budget of the Earth due to their optical, microphysical and chemical properties, and are considered one of the most uncertain climate forcing agents. In order to characterise the uncertainties associated with satellite and modelling approaches to represent aerosol optical properties, mainly aerosol optical depth (AOD) and Ångström exponent (AE), their representation by different remote-sensing sensors and regional online coupled chemistry–climate models over Europe are evaluated. This work also characterises whether the inclusion of aerosol–radiation (ARI) or/and aerosol–cloud interactions (ACI) help improve the skills of modelling outputs.Two case studies were selected within the EuMetChem COST Action ES1004 framework when important aerosol episodes in 2010 all over Europe took place: a Russian wildfire episode and a Saharan desert dust outbreak that covered most of the Mediterranean Sea. The model data came from different regional air-quality–climate simulations performed by working group 2 of EuMetChem, which differed according to whether ARI or ACI was included or not. The remote-sensing data came from three different sensors: MODIS, OMI and SeaWIFS. The evaluation used classical statistical metrics to first compare satellite data versus the ground-based instrument network (AERONET) and then to evaluate model versus the observational data (both satellite and ground-based data).Regarding the uncertainty in the satellite representation of AOD, MODIS presented the best agreement with the AERONET observations compared to other satellite AOD observations. The differences found between remote-sensing sensors highlighted the uncertainty in the observations, which have to be taken into account when evaluating models. When modelling results were considered, a common trend for underestimating high AOD levels was observed. For the AE, models tended to underestimate its variability, except when considering a sectional approach in the aerosol representation. The modelling results showed better skills when ARI+ACI interactions were included; hence this improvement in the representation of AOD (above 30 % in the model error) and AE (between 20 and 75 %) is important to provide a better description of aerosol–radiation–cloud interactions in regional climate models.

scholarly journals Simulation of aerosol optical properties over a tropical urban site in India using a global model and its comparison with ground measurements

2011 ◽  
Vol 29 (5) ◽  
pp. 955-963 ◽  
Author(s):  
D. Goto ◽  
K. V. S. Badarinath ◽  
T. Takemura ◽  
T. Nakajima
Keyword(s):  
Optical Properties ◽  
General Circulation ◽  
Three Dimensional ◽  
Temporal Distribution ◽  
Circulation Model ◽  
Global Model ◽  
Atmospheric Environment ◽  
Urban Site ◽  
Aerosol Optical Properties ◽  
Aerosol Emission

Abstract. Aerosols have great impacts on atmospheric environment, human health, and earth's climate. Therefore, information on their spatial and temporal distribution is of paramount importance. Despite numerous studies have examined the variation and trends of BC and AOD over India, only very few have focused on their spatial distribution or even correlating the observations with model simulations. In the present study, a three-dimensional aerosol transport-radiation model coupled with a general circulation model. SPRINTARS, simulated atmospheric aerosol distributions including BC and aerosol optical properties, i.e., aerosol optical thickness (AOT), Ångström Exponent (AE), and single scattering albedo (SSA). The simulated results are compared with both BC measurements by aethalometer and aerosol optical properties measured by ground-based skyradiometer and by satellite sensor, MODIS/Terra over Hyderabad, which is a tropical urban area of India, for the year 2008. The simulated AOT and AE in Hyderabad are found to be comparable to ground-based measured ones. The simulated SSA tends to be higher than the ground-based measurements. Both these comparisons of aerosol optical properties between the simulations with different emission inventories and the measurements indicate that, firstly the model uncertainties derived from aerosol emission inventory cannot explain the gaps between the simulations and the measurements and secondly the vertical transport of BC and the treatment of BC-containing particles can be the main issue in the global model to solve the gap.

scholarly journals Measurement report: Long-term changes in black carbon and aerosol optical properties from 2012 to 2020 in Beijing, China

2022 ◽  
Vol 22 (1) ◽  
pp. 561-575
Author(s):  
Jiaxing Sun ◽  
Zhe Wang ◽  
Wei Zhou ◽  
Conghui Xie ◽  
Cheng Wu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Black Carbon ◽  
Seasonal Variations ◽  
Radiative Forcing ◽  
Action Plan ◽  
Aerosol Optical Properties ◽  
Long Term Changes ◽  
Clean Air ◽  
Beijing China

Abstract. Atmospheric aerosols play an important role in the radiation balance of the earth–atmosphere system. However, our knowledge of the long-term changes in equivalent black carbon (eBC) and aerosol optical properties in China is very limited. Here we analyze the 9-year measurements of eBC and aerosol optical properties from 2012 to 2020 in Beijing, China. Our results showed large reductions in eBC by 71 % from 6.25 ± 5.73 µg m−3 in 2012 to 1.80 ± 1.54 µg m−3 in 2020 and 47 % decreases in the light extinction coefficient (bext, λ = 630 nm) of fine particles due to the Clean Air Action Plan that was implemented in 2013. The seasonal and diurnal variations of eBC illustrated the most significant reductions in the fall and at nighttime, respectively. ΔeBC / ΔCO also showed an annual decrease from ∼ 7 to 4 ng m−3 ppbv−1 and presented strong seasonal variations with high values in spring and fall, indicating that primary emissions in Beijing have changed significantly. As a response to the Clean Air Action Plan, single-scattering albedo (SSA) showed a considerable increase from 0.79 ± 0.11 to 0.88 ± 0.06, and mass extinction efficiency (MEE) increased from 3.2 to 3.8 m2 g−1. These results highlight the increasing importance of scattering aerosols in radiative forcing and a future challenge in visibility improvement due to enhanced MEE. Brown carbon (BrC) showed similar changes and seasonal variations to eBC during 2018–2020. However, we found a large increase of secondary BrC in the total BrC in most seasons, particularly in summer with the contribution up to 50 %, demonstrating an enhanced role of secondary formation in BrC in recent years. The long-term changes in eBC and BrC have also affected the radiative forcing effect. The direct radiative forcing (ΔFR) of BC decreased by 67 % from +3.36 W m−2 in 2012 to +1.09 W m−2 in 2020, and that of BrC decreased from +0.30 to +0.17 W m−2 during 2018–2020. Such changes might have important implications for affecting aerosol–boundary layer interactions and the improvement of future air quality.

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