A comprehensive reappraisal of long-term aerosol characteristics, trends, and variability in Asia

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(14), С. 8187 - 8210

Опубликована: Июль 24, 2023

Abstract. Changes in aerosol loadings and properties are important for the understanding of atmospheric environment climate change. This study investigates characteristics long-term trends aerosols different sizes types Asia from 2000 to 2020 by considering multi-source data novel analysis methods perspectives, all which provides groundwork promoting acquisition new discoveries that past. The geometric mean aggregation method is applied, serial autocorrelation considered avoid overestimation trend significance. Among regions Asia, high values optical depth (AOD) mainly concentrated East (EA) South (SA) closely related population density. AOD EA showed most significant negative trend, with a value -5.28×10-4 per year, owing decreases organic carbon (OC), black (BC), dust aerosols. It also worth noting this observed large-scale decrease OC BC unique phenomenon region around China. In contrast, concentrations SA generally show positive an increased 1.25 × 10−3 year. increase due large emissions fine-mode aerosols, such as sulfate aerosol. Additionally, loading northern has lower variability when compared China Plain, revealing relatively more persistent air pollution situation. Over whole percentage changes seen increases (6.23 %) (17.09 AOD, together (−5.51 %), (−3.07 sea salt (−9.80 AOD. Except anthropogenic emissions, wildfires found summer, whereas differently sized only shows slight small-sized (−3.34 total did not suggests that, perspective, recent years have mostly been offsetting earlier over Asia. To summarize, above findings analyse comprehensive distributions reappraise parameters, will greatly enhance regional global climatology, addition filling gaps breaking through limitations past knowledge.

Язык: Английский

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Reconstructing MODIS aerosol optical depth and exploring dynamic and influential factors of AOD via random forest at the global scale

Atmospheric Environment, Год журнала: 2023, Номер 315, С. 120159 - 120159

Опубликована: Окт. 18, 2023

Язык: Английский

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Towards long-term, high-accuracy, and continuous satellite total and fine-mode aerosol records: Enhanced Land General Aerosol (e-LaGA) retrieval algorithm for VIIRS

ISPRS Journal of Photogrammetry and Remote Sensing, Год журнала: 2024, Номер 214, С. 261 - 281

Опубликована: Июль 1, 2024

Язык: Английский

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Research on Time Series Interpolation and Reconstruction of Multi-Source Remote Sensing AOD Product Data Using Machine Learning Methods

Atmosphere, Год журнала: 2025, Номер 16(6), С. 655 - 655

Опубликована: Май 28, 2025

The satellite remote sensing of Aerosol Optical Depth (AOD) products is crucial in environmental monitoring and atmospheric pollution research. However, data gaps AOD from satellites like Fengyun significantly hinder continuous, seamless capabilities, posing challenges for the long-term analysis trends, responses to sudden ecological events, disaster management. This study aims develop a high-precision method fill spatial missing values generate daily full-coverage Beijing–Tianjin–Hebei region 2021 by integrating multi-dimensional data, including meteorological models, multi-source sensing, surface conditions, nighttime light parameters, applying machine learning methods. A comparison five models showed that random forest model performed optimally inversion, achieving root mean square error (RMSE) 0.11 coefficient determination (R2) 0.93. Seasonal evaluation further indicated model’s simulation was best winter. Variable importance identified relative humidity (RH) as most critical factor influencing results. reconstructed product exhibited distribution trend higher southern plain areas compared mountainous regions, consistent with actual aerosol patterns area. Moreover, demonstrated overall smoothness high accuracy. research lays foundation establishing long-term, 1 km resolution, spatially continuous beyond, providing more robust support addressing regional larger-scale challenges.

Язык: Английский

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Evaluation and analysis of long-term MODIS MAIAC aerosol products in China

The Science of The Total Environment, Год журнала: 2024, Номер 948, С. 174983 - 174983

Опубликована: Июль 22, 2024

Язык: Английский

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How is the spatiotemporal representativeness of ground- and satellite-based aerosol optical depth (AOD) measurements over Asia?

Atmospheric Research, Год журнала: 2024, Номер unknown, С. 107857 - 107857

Опубликована: Дек. 1, 2024

Язык: Английский

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Emission Reductions Significantly Reduce the Hemispheric Contrast in Cloud Droplet Number Concentration in Recent Two Decades

Journal of Geophysical Research Atmospheres, Год журнала: 2023, Номер 128(2)

Опубликована: Янв. 7, 2023

Abstract Anthropogenic activities have drastically impacted the climate system since Industrial Revolution. However, to what extent anthropogenic emissions influence cloud droplet number concentration ( N d ), critical parameter for understanding aerosol‐cloud interactions, is poorly known on hemispheric scale due considerable retrieval uncertainty. We employed multiple widely used sampling methods evaluate long‐term trend in contrast (Δ d(NH‐SH) ) between Northern Hemisphere (NH) and Southern (SH). Here we show that Δ was halved from 2003 2020 using different channels, even though range of magnitudes large. Such dramatic changes are dominated by significantly decreased over NH (∼20%) emission reductions compared relatively stable pristine nature SH. Aerosol optical depth (AOD) aerosol index (AI) correlate with based trends, they replicate trends. This poor correlation partly contributed stratospheric smoke wildfires Australia had little The northwest Atlantic shows largest contribution, ∼38%, trend, whereas Pacific dominates change AOD AI, contributing more than 60% ∼50% AI NH. Our results imply reduced provide strong observational evidence extensively altered liquid clouds last two decades.

Язык: Английский

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Evaluation and Comparison of Multi-Satellite Aerosol Optical Depth Products over East Asia Ocean

Toxics, Год журнала: 2023, Номер 11(10), С. 813 - 813

Опубликована: Сен. 26, 2023

The atmosphere over the ocean is an important research field that involves multiple aspects such as climate change, atmospheric pollution, weather forecasting, and marine ecosystems. It of great significance for global sustainable development. Satellites provide a wide range measurements aerosol optical properties are very to study characteristics ocean. In this study, depth (AOD) data from seventeen AERONET (Aerosol Robotic Network) stations were used benchmark comprehensively evaluate accuracy six thickness products 2013 2020, including MODIS (Moderate-resolution Imaging Spectrometer), VIIRS (Visible Infrared Radiometer Suite), MISR (Multi-Angle OMAERO (OMI/Aura Multi-wavelength algorithm), OMAERUV Near UV CALIPSO (Cloud-Aerosol Lidar Pathfinder Satellite Observation) in East Asian Ocean. Asia Sea, AOD generally have higher correlation coefficient (R), expected error within ratio (EE within), lower root mean square (RMSE), median bias (MB) than products. retrieval highest spring. showed EE other Ocean but also exhibited systematic underestimation. most cases, product better quality OMAERO, overestimates throughout year. apparent underestimation different seasons Below = 58.98%), when small (0 < 0.1), compared with satellite under range. South China has MISR, while Bohai-Yellow Sea Japan, western Pacific Ocean, best accuracy. show similar trends R, within, MB, RMSE influence AOD, Angstrom exponent (AE), precipitable water. on temporal spatial distribution shows annual variation sea areas, coastal area greatly affected by land-based pollution. contrast, values offshore areas lower, type mainly clean aerosol. These findings can help researchers choose accurate reliable aerosols' impact trends.

Язык: Английский

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Assessment and characteristics of S-NPP VIIRS Deep Blue and Dark Target aerosol properties under clean, polluted and fire scenarios over the Amazon

Atmospheric Environment, Год журнала: 2024, Номер 323, С. 120398 - 120398

Опубликована: Фев. 12, 2024

Язык: Английский

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First retrieval of daily 160 m aerosol optical depth over urban areas using Gaofen-1/6 synergistic observations: Algorithm development and validation

ISPRS Journal of Photogrammetry and Remote Sensing, Год журнала: 2024, Номер 211, С. 372 - 391

Опубликована: Апрель 22, 2024

The satellite-based aerosol optical depth (AOD), which can provide continuous spatial observations of loadings, is widely adopted to estimate atmospheric environmental quality and evaluate its risk for human health. However, current satellite-retrieved AOD products characterized by a comparatively coarse resolution (≥1 km) hardly analyze the structure pollution or correlation with urban landscapes over populated areas. Existed studies have tried address this deficiency retrieving high-resolution using Landsat images, whose long revisit period (16 days nominally), however, largely limits applications related air research. To achieve both high expected from satellite observation, in study, comprehensive retrieval framework developed Wide-Field-of-View (WFV) sensors yield daily dataset areas 160 m resolution, based on Gaofen-1 Gaofen-6 synergistic observations. crucial challenge that complex landscape contribute dramatic variation land surface bidirectional reflectance, Simulated-Annealing-coupled Semiempirical Modified Rahman-Pinty-Verstraete (SAS-MRPV) scheme proposed model reflectance (LSR) framework, where SAS-MRPV implemented simulated annealing iteration initialized distribution function (BRDF) Moderate Resolution Imaging Spectrometer (MODIS) as priori knowledge. validation results demonstrate Gaofen WFV retrievals exhibit good agreement ground-based AErosol RObotic NETwork (AERONET) SONET (Sun-sky radiometer Observation NETwork) AOD, demonstrating coefficient error (EE)±(0.05 + 0.15AODAERONET/SONET) ratio respectively reaching up 0.97 80 %, only slight bias fluctuations are found under different cover types, loading, seasonal conditions. Moreover, retrievals, LSR estimated scheme, MODIS BRDF Products, Minimum Reflectance Technique (MRT) method, better accuracy completeness SAS-MPRV natural impervious surfaces, indicating stability reliability determination retrieval. In addition that, analyses control effective necessary guarantee estimation identifying excluding pixels unsuitable modeling, mitigates uncertainty final products. Furthermore, inter-comparison between WFV-derived against operational Deep Blue (10 km), Dark Target (3 Multi-Angle Implementation Atmospheric Correction (MAIAC, 1 demonstrates basis obtaining similar overall descriptions possess capability characterize at finer scale smoother clean polluted With outstanding reliable performance, exhibits substantial potential observations, could be directly applied other supporting further emission management health assessment extra-fine scale.

Язык: Английский

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