The Impact of Dust Storms on Aerosol Optical Depth and Radiative Forcing

2020 ◽  
Vol 16 (1) ◽  
pp. 1-14
Author(s):  
Monim Jiboori ◽  
Nadia Abed ◽  
Mohamed Abdel Wahab
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Dust Storms ◽  
The Impact

The Impact of Dust Storms on Aerosol Optical Depth and Radiative Forcing

2020 ◽  
Vol 16 (1) ◽  
pp. 1-14
Author(s):  
Monim Jiboori ◽  
Nadia Abed ◽  
Mohamed Abdel Wahab
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Dust Storms ◽  
The Impact

scholarly journals Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect

2013 ◽  
Vol 13 (15) ◽  
pp. 7895-7901 ◽  
Author(s):  
A. Arola ◽  
T. F. Eck ◽  
J. Huttunen ◽  
K. E. J. Lehtinen ◽  
A. V. Lindfors ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Radiative Effect ◽  
Diurnal Variability ◽  
Diurnal Cycles ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Impact

Abstract. The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was typically around 0.1–0.2 W m−2 (both positive and negative) in absolute values, 5–10% in relative ones.

scholarly journals Modelled and observed changes in aerosols and surface solar radiation over Europe between 1960 and 2009

2015 ◽  
Vol 15 (9) ◽  
pp. 13457-13513 ◽  
Author(s):  
S. T. Turnock ◽  
D. V. Spracklen ◽  
K. S. Carslaw ◽  
G. W. Mann ◽  
M. T. Woodhouse ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Sulfate Aerosol ◽  
Anthropogenic Aerosols ◽  
Surface Solar Radiation ◽  
Aerosol Mass ◽  
The Impact ◽  
Aerosol Radiative

Abstract. Substantial changes in anthropogenic aerosols and precursor gas emissions have occurred over recent decades due to the implementation of air pollution control legislation and economic growth. The response of atmospheric aerosols to these changes and the impact on climate are poorly constrained, particularly in studies using detailed aerosol chemistry climate models. Here we compare the HadGEM3-UKCA coupled chemistry-climate model for the period 1960 to 2009 against extensive ground based observations of sulfate aerosol mass (1978–2009), total suspended particle matter (SPM, 1978–1998), PM10 (1997–2009), aerosol optical depth (AOD, 2000–2009) and surface solar radiation (SSR, 1960–2009) over Europe. The model underestimates observed sulfate aerosol mass (normalised mean bias factor (NMBF) = −0.4), SPM (NMBF = −0.9), PM10 (NMBF = −0.2) and aerosol optical depth (AOD, NMBF = −0.01) but slightly overpredicts SSR (NMBF = 0.02). Trends in aerosol over the observational period are well simulated by the model, with observed (simulated) changes in sulfate of −68% (−78%), SPM of −42% (−20%), PM10 of −9% (−8%) and AOD of −11% (−14%). Discrepancies in the magnitude of simulated aerosol mass do not affect the ability of the model to reproduce the observed SSR trends. The positive change in observed European SSR (5%) during 1990–2009 ("brightening") is better reproduced by the model when aerosol radiative effects (ARE) are included (3%), compared to simulations where ARE are excluded (0.2%). The simulated top-of-the-atmosphere aerosol radiative forcing over Europe under all-sky conditions increased by 3 W m−2 during the period 1970–2009 in response to changes in anthropogenic emissions and aerosol concentrations.

scholarly journals Radiative impact of an extreme Arctic biomass-burning event

2018 ◽  
Vol 18 (12) ◽  
pp. 8829-8848 ◽  
Author(s):  
Justyna Lisok ◽  
Anna Rozwadowska ◽  
Jesper G. Pedersen ◽  
Krzysztof M. Markowicz ◽  
Christoph Ritter ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Biomass Burning ◽  
Radiative Forcing ◽  
Radiation Budget ◽  
Plane Parallel ◽  
Direct Radiative Forcing ◽  
The Mean ◽  
The Impact

Abstract. The aim of the presented study was to investigate the impact on the radiation budget of a biomass-burning plume, transported from Alaska to the High Arctic region of Ny-Ålesund, Svalbard, in early July 2015. Since the mean aerosol optical depth increased by the factor of 10 above the average summer background values, this large aerosol load event is considered particularly exceptional in the last 25 years. In situ data with hygroscopic growth equations, as well as remote sensing measurements as inputs to radiative transfer models, were used, in order to estimate biases associated with (i) hygroscopicity, (ii) variability of single-scattering albedo profiles, and (iii) plane-parallel closure of the modelled atmosphere. A chemical weather model with satellite-derived biomass-burning emissions was applied to interpret the transport and transformation pathways. The provided MODTRAN radiative transfer model (RTM) simulations for the smoke event (14:00 9 July–11:30 11 July) resulted in a mean aerosol direct radiative forcing at the levels of −78.9 and −47.0 W m−2 at the surface and at the top of the atmosphere, respectively, for the mean value of aerosol optical depth equal to 0.64 at 550 nm. This corresponded to the average clear-sky direct radiative forcing of −43.3 W m−2, estimated by radiometer and model simulations at the surface. Ultimately, uncertainty associated with the plane-parallel atmosphere approximation altered results by about 2 W m−2. Furthermore, model-derived aerosol direct radiative forcing efficiency reached on average −126 W m-2/τ550 and −71 W m-2/τ550 at the surface and at the top of the atmosphere, respectively. The heating rate, estimated at up to 1.8 K day−1 inside the biomass-burning plume, implied vertical mixing with turbulent kinetic energy of 0.3 m2 s−2.

scholarly journals Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect

2013 ◽  
Vol 13 (4) ◽  
pp. 10327-10344 ◽  
Author(s):  
A. Arola ◽  
T. F. Eck ◽  
J. Huttunen ◽  
K. E. J. Lehtinen ◽  
A. V. Lindfors ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Radiative Effect ◽  
Diurnal Variability ◽  
Diurnal Cycles ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Impact

Abstract. The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability on the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates, while by focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was typically around 0.1–0.2 W m−2 (both positive and negative).

scholarly journals Impact of a Strong Biomass Burning Event on the Radiative Forcing in the Arctic

2017 ◽  
Author(s):  
Justyna Lisok ◽  
Anna Rozwadowska ◽  
Jesper G. Pedersen ◽  
Krzysztof M. Markowicz ◽  
Christoph Ritter ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Biomass Burning ◽  
Radiative Forcing ◽  
Radiation Budget ◽  
The Arctic ◽  
Plane Parallel ◽  
Direct Radiative Forcing ◽  
The Mean ◽  
The Impact

Abstract. The aim of the presented study was to investigate the impact on the radiation budget of biomass burning smoke plume transported from Alaska to high Arctic region (Ny-Alesund, Svalbard) in early July 2015. This high aerosol load event is considered exceptional in the last 25 years with mean aerosol optical depth increased by the factor of 10 in comparison to the average summer background values. We utilised in-situ data with hygroscopic growth equations as well as remote sensing measurements as inputs to radiative transfer models with an objective to estimate biases associated with (i) hygroscopicity, (ii) variability of ω profiles and (iii) plane-parallel closure of the modelled atmosphere. A chemical weather model with satellite-derived biomass burning emissions was used to interpret the transport and transformations pathways. Provided MODTRAN simulations resulted in the mean aerosol direct radiative forcing on the level of −78.9 W m−2 and −47.0 W m−2 at the surface and the top of the atmosphere respectively for the mean value of aerosol optical depth equal to 0.64 at 550 nm. It corresponded to the average clear-sky direct radiative forcing of −43.3 W m−2 estimated by radiometers and model simulations. Furthermore, model-derived aerosol direct radiative forcing efficiency reached on average −126 W m−2 / τ550 and −71 W m−2 / τ550 at the surface and at the top of the atmosphere. Estimated heating rate up to 1.8 K day−1 inside the BB plume implied vertical mixing with the turbulent kinetic energy of 0.3 m2 s−2. Ultimately, uncertainty connected with the plane-parallel atmosphere approximation altered results by about 2 W m−2.

scholarly journals The Impact of Dust Storms on Aerosol Optical Depth and Radiative Force

2020 ◽  
Vol 16 (1) ◽  
pp. 1-15
Author(s):  
Monim H. ◽  
Nadia M. ◽  
Mohamed Wahab
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Dust Storms ◽  
Radiative Force ◽  
The Impact

scholarly journals Monitoring the Spatial Variation of Aerosol Optical Depth and Its Correlation with Land Use/Land Cover in Wuhan, China: A Perspective of Urban Planning

2021 ◽  
Vol 18 (3) ◽  
pp. 1132
Author(s):  
Qijiao Xie ◽  
Qi Sun
Keyword(s):  
Land Use ◽  
Air Quality ◽  
Urban Planning ◽  
Land Cover ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Water Bodies ◽  
Landsat 8 ◽  
Land Use Land Cover ◽  
The Impact

Aerosols significantly affect environmental conditions, air quality, and public health locally, regionally, and globally. Examining the impact of land use/land cover (LULC) on aerosol optical depth (AOD) helps to understand how human activities influence air quality and develop suitable solutions. The Landsat 8 image and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products in summer in 2018 were used in LULC classification and AOD retrieval in this study. Spatial statistics and correlation analysis about the relationship between LULC and AOD were performed to examine the impact of LULC on AOD in summer in Wuhan, China. Results indicate that the AOD distribution expressed an obvious “basin effect” in urban development areas: higher AOD values concentrated in water bodies with lower terrain, which were surrounded by the high buildings or mountains with lower AOD values. The AOD values were negatively correlated with the vegetated areas while positively correlated to water bodies and construction lands. The impact of LULC on AOD varied with different contexts in all cases, showing a “context effect”. The regression correlations among the normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), normalized difference water index (NDWI), and AOD in given landscape contexts were much stronger than those throughout the whole study area. These findings provide sound evidence for urban planning, land use management and air quality improvement.

scholarly journals Eurasia large-scale hazes in summer 2016

2019 ◽  
Vol 55 (3) ◽  
pp. 41-51
Author(s):  
G. I. Gorchakov ◽  
S. A. Sitnov ◽  
A. V. Karpov ◽  
I. A. Gorchakova ◽  
R. A. Gushchin ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Large Scale ◽  
Empirical Distribution ◽  
Growth Period ◽  
Maximum Growth ◽  
Qualitative Change ◽  
Smoke Aerosol

Using maximum aerosol optical depth (MAOD) spatial distribution formation technique the optically dense haze expansion scales in period from 15 to 31 July 2016 over Eurasia are estimated in during great Siberian smoke haze (SSH) with the area 16 mln km2 about, smog over the Northern China Plain (2 mln km2), dust haze in Takla Makan desert (0.8 mln km2) and hazes in India and Pakistan (1 mln km2 approximately). Empirical distribution function (EDF) MAOD is received which is approximated by linear function of MAOD logarithm. Aerosol optical depth (AOD) spatial distribution at wavelength 550 nm in SSH is analyzed. Total smoke aerosol mass assessment in SSH (3.2 mln tons) is evaluated. Smoke aerosol (SA) mass during maximum growth period from 22 July to 26 July 2016 over Siberia (50°-70°, 60°-120 °E) was equal 2 mln tons approximately. Aerosol index (AI) temporal variability is illustrated visually SA composition qualitative change in SSH during long-range transport. It is shown that AI variations are correlated with AOD variations. Aerosol radiative forcing (ARF) at the top and the bottom of the atmosphere over Siberia from 22 July to 26 July 2016 is estimated (average ARF are equal –68 and –98 W/m2). EDF AOD and EDF ARF at the top of the atmosphere are approximated by exponential and power function of AOD correspondingly.

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