Aerosol Direct Radiative Effects under Cloud-Free Conditions over Highly-Polluted Areas in Europe and Mediterranean: A Ten-Years Analysis (2007–2016)

Landi, Tony Christian; Bonasoni, Paolo; Brunetti, Michele; Campbell, James; Marquis, Jared W.; Girolamo, Paolo Di; Lolli, Simone

doi:10.3390/rs13152933

Cited by 9 publications

(5 citation statements)

References 55 publications

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“…We use SZA for each box at noon local time of the 15th day of that month. Following the approach used in Landi et al (2021), we applied a constant (wavelength-independent) albedo value of 0.12 for urban environments, 0.15 for vegetated areas, and 0.37 for desertic regions (obtained integrating the hemispherical directional reflectance, Strahler et al, 1999) while the infrared surface emissivity is set to a constant value of 0.98.…”

Section: Drf Hr Flg Totalsky − Flg Pristinementioning

confidence: 99%

Radiative Impacts of Aerosols During COVID-19 Lockdown Period Over the Indian Region

Bhawar

Kumar

Rahul

et al. 2021

Front. Environ. Sci.

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The COVID-19 lockdown restrictions influenced global atmospheric aerosols. We report aerosol variations over India using multiple remote sensing datasets [Moderate Resolution Imaging Spectroradiometer (MODIS), Ozone Monitoring Instrument (OMI), Cloud-Aerosol Lidar, and Infrared Pathfinder (CALIPSO)], and model reanalysis [Copernicus Atmosphere Monitoring Service (CAMS)] during the lockdown implemented during the COVID-19 pandemic outbreak period from March 25 to April 14, 2020. Our analysis shows that, during this period, MODIS and CALIPSO showed a 30–40% reduction in aerosol optical depth (AOD) over the Indo-Gangetic Plain (IGP) with respect to decadal climatology (2010–2019). The absorbing aerosol index and dust optical depth measurements also showed a notable reduction over the Indian region, highlighting less emission of anthropogenic dust and also a reduced dust transport from West Asia during the lockdown period. On the contrary, central India showed an ∼12% AOD enhancement. CALIPSO measurements revealed that this increase was due to transported biomass burning aerosols. Analysis of MODIS fire data product and CAMS fire fluxes (black carbon, SO2, organic carbon, and nitrates) showed intense fire activity all over India but densely clustered over central India. Thus, we show that the lockdown restrictions implemented at the government level have significantly improved the air quality over northern India but fires offset its effects over central India. The biomass-burning aerosols formed a layer near 2–4 km (AOD 0.08–0.1) that produced heating at 3–4 K/day and a consequent negative radiative forcing at the surface of ∼−65 W/m2 (±40 W/m2) over the central Indian region.

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Section: Drf Hr Flg Totalsky − Flg Pristinementioning

confidence: 99%

Radiative Impacts of Aerosols During COVID-19 Lockdown Period Over the Indian Region

Bhawar

Kumar

Rahul

et al. 2021

Front. Environ. Sci.

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“…Barcelona, Spain, is in a large coastal metropolitan area in the Mediterranean region (41.384 • N, 2.120 • E, 115 m a.s.l. ), a region where climate is changing at a fast pace [30]. The measurement site is highly affected by urban and marine particles, Barcelona's local aerosols, and transported desert dust outbreaks and biomass burning from forest fires in the summer due to vegetation dryness [31].…”

Section: Characterization Of the Measurement Sitementioning

confidence: 99%

Evaluation of the Accuracy of the Aerosol Optical and Microphysical Retrievals by the GRASP Algorithm from Combined Measurements of a Polarized Sun-Sky-Lunar Photometer and a Three-Wavelength Elastic Lidar

dos Santos Oliveira,

Sicard,

Rodríguez-Gómez

et al. 2023

Remote Sensing

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The versatile Generalized Retrieval of Aerosol and Surface Properties (GRASP) algorithm exploits the advantages of synergic ground-based aerosol observations such as radiometric (sensitive to columnar aerosol optical and microphysical properties) and lidar (sensitive to vertical distribution of the optical properties) observations. The synergy is possible when the complementary data is mutually constrained by GRASP parametrization that includes, for the first time ever, the degree of linear polarization (DoLP) parameter measured by a polarized sun-sky-lunar AERONET photometer (380, 440, 500, 675, 870, 1020, and 1640 nm) in synergy with the vertical profiles from an elastic lidar (355, 532, and 1064 nm). First, a series of numerical tests is performed using simulated data generated using a climatology of data and ground-based measurements. The inversions are performed with and without random noise for five different combinations of input data, starting from the AERONET-like dataset and increasing to the complex one by adding more information for three aerosol scenarios: I—high aerosol optical depth (AOD) with dominant coarse mode; II—low AOD with dominant coarse mode; III—high AOD with dominant fine mode. The inclusion of DoLP improves (i) the retrieval accuracy of the fine-mode properties when it is not dominant; (ii) the retrieval accuracy of the coarse-mode properties at longer wavelengths and that of the fine-mode properties at shorter wavelengths; (iii) the retrieval accuracy of the coarse-mode real part of the refractive index (up to 36% reduction), but has no effect on the retrieval of the imaginary part; (iv) reduces up to 83% the bias of the sphere fraction (SF) retrieval in coarse-mode dominated regimes; and (v) the root mean square error (RMSE) of the retrieval for most of the parameters in all scenarios. In addition, the addition of more photometer channels in synergy with a three-wavelength elastic lidar reduces the RMSE for the real part (67% in the coarse mode) and the imaginary part (35% in the fine mode) of the refractive index, the single scattering albedo (38% in the fine mode), the lidar ratio (20% in the coarse mode), and the SF (43%).

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“…Among all different aerosol species, the detection of biomass burning events [6] and dust outbreaks using multispectral (MS) imagery, particularly in the Mediterranean region, represents a critical area of remote sensing research, as these events are increasingly influencing air quality. The unique geographic and climatic characteristics of the Mediterranean make it susceptible to frequent dust events from the Sahara [7] and biomass burning advections, both of which have significant implications for air quality, climate, and human health. Furthermore, the Mediterranean region is defined as a "climate hotspot", where climate change occurs more rapidly than in other parts of the world [8,9].…”

Section: Introductionmentioning

confidence: 99%

“…Shifting the focus to another major atmospheric issue, dust, primarily from the Sahara, poses a distinct challenge in aerosol monitoring. It significantly impacts air quality, sunlight exposure, and ecosystems [7,13,14]. Sentinel-3, equipped with the Ocean and Land Color Instrument (OLCI) and the Sea and Land Surface Temperature Radiometer (SLSTR), provides important information for identifying and monitoring dust events.…”

Section: Introductionmentioning

confidence: 99%

Characterizing Dust and Biomass Burning Events from Sentinel-2 Imagery

Lolli,

Alparone,

Arienzo

et al. 2024

Atmosphere

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The detection and evaluation of biomass burning and dust events are critical for understanding their impact on air quality, climate, and human health, particularly in the Mediterranean region. This research pioneers an innovative methodology that uses Sentinel-2 multispectral (MS) imagery to meticulously pinpoint and analyze long-transport dust outbreaks and biomass burning phenomena, originating both locally and transported from remote areas. We developed the dust/biomass burning (DBB) composite normalized differential index, a tool that identifies clear, dusty, and biomass burning scenarios in the selected region. The DBB index jointly employs specific Sentinel-2 bands: B2-B3-B4 for visible light analysis, and B11 and B12 for short-wave infrared (SWIR), exploiting the specificity of each wavelength to assess the presence of different aerosols. A key feature of the DBB index is its normalization by the surface reflectance of the scene, which ensures independence from the underlying texture, such as streets and buildings, for urban areas. The differentiation involves the comparison of the top-of-atmosphere (TOA) reflectance values from aerosol events with those from clear-sky reference images, thereby constituting a sort of calibration. The index is tailored for urban settings, where Sentinel-2 imagery provides a decametric spatial resolution and revisit time of 5 days. The average values of DBB achieve a 96% match with the coarse-mode aerosol optical depths (AOD), measured by a local station of the AERONET network of sun-photometers. In future studies, the map of DBB could be integrated with that achieved from Sentinel-3 images, which offer similar spectral bands, albeit with much less fine spatial resolution, yet benefit from daily coverage.

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Aerosol Direct Radiative Effects under Cloud-Free Conditions over Highly-Polluted Areas in Europe and Mediterranean: A Ten-Years Analysis (2007–2016)

Cited by 9 publications

References 55 publications

Radiative Impacts of Aerosols During COVID-19 Lockdown Period Over the Indian Region

Radiative Impacts of Aerosols During COVID-19 Lockdown Period Over the Indian Region

Evaluation of the Accuracy of the Aerosol Optical and Microphysical Retrievals by the GRASP Algorithm from Combined Measurements of a Polarized Sun-Sky-Lunar Photometer and a Three-Wavelength Elastic Lidar

Characterizing Dust and Biomass Burning Events from Sentinel-2 Imagery

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