Corrigendium to “Estimation of the 2002 mount etna eruption cloud radiative forcing from meteosat-7 data” [Remote Sensing of Environment 87 (2003) 257–272]

Abstract. In this paper we combine SO2 and ash plume dispersion modelling with satellite and surface remote sensing observations to study the regional influence of a relatively weak volcanic eruption from Mount Etna on the optical and micro-physical properties of Mediterranean aerosols. We analyse the Mount Etna eruption episode of 25–27 October 2013. The evolution of the plume along the trajectory is investigated by means of the FLEXible PARTicle Lagrangian dispersion (FLEXPART) model. The satellite data set includes true colour images, retrieved values of volcanic SO2 and ash, estimates of SO2 and ash emission rates derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations and estimates of cloud top pressure from SEVIRI (Spinning Enhanced Visible and InfraRed Imager). Surface remote sensing measurements of aerosol and SO2 made at the ENEA Station for Climate Observations (35.52° N, 12.63° E; 50 m a.s.l.) on the island of Lampedusa are used in the analysis. The combination of these different data sets suggests that SO2 and ash, despite the initial injection at about 7.0 km altitude, reached altitudes around 10–12 km and influenced the column average aerosol particle size distribution at a distance of more than 350 km downwind. This study indicates that even a relatively weak volcanic eruption may produce an observable effect on the aerosol properties at the regional scale. The impact of secondary sulfate particles on the aerosol size distribution at Lampedusa is discussed and estimates of the clear-sky direct aerosol radiative forcing are derived. Daily shortwave radiative forcing efficiencies, i.e. radiative forcing per unit AOD (aerosol optical depth), are calculated with the LibRadtran model. They are estimated between −39 and −48 W m−2 AOD−1 at the top of the atmosphere and between −66 and −49 W m−2 AOD−1 at the surface, with the variability in the estimates mainly depending on the aerosol single scattering albedo. These results suggest that sulfate particles played a large role in the transported plume composition and radiative forcing, while the contribution by ash particles was small in the volcanic plume arriving at Lampedusa during this event.

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Synergistic use of Lagrangian dispersion modelling, satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-31335-2015 ◽

2015 ◽

Vol 15 (21) ◽

pp. 31335-31383 ◽

Cited By ~ 3

Author(s):

P. Sellitto ◽

A. di Sarra ◽

S. Corradini ◽

M. Boichu ◽

H. Herbin ◽

...

Keyword(s):

Remote Sensing ◽

Size Distribution ◽

Volcanic Eruption ◽

Radiative Forcing ◽

Dispersion Model ◽

Mount Etna ◽

Aerosol Size Distribution ◽

Dispersion Modelling ◽

Lagrangian Dispersion ◽

The Impact

Abstract. In this paper we combine SO2/ash plume dispersion modelling, satellite and surface remote sensing observations to study the regional influence of a relatively weak volcanic eruption from Mount Etna on the optical and micro-physical properties of Mediterranean aerosols. We analyse the Mount Etna eruption episode of 25–27 October 2013. The evolution of the plume along the trajectory is investigated by means of the FLEXPART (FLEXible PARTicle dispersion model) Lagrangian dispersion model. The satellite dataset includes true colour images, retrieved values of volcanic SO2 and ash, and estimates of SO2 and ash emission rates derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations, and estimates of cloud top pressure from SEVIRI (Spinning Enhanced Visible and InfraRed Imager). Surface remote sensing measurements of aerosol and SO2 made at the ENEA Station for Climate Observations (35.52° N, 12.63° E, 50 m a.s.l.) on the island of Lampedusa are used in the analysis. The combination of these different datasets suggests that SO2 and ash, despite the initial injection occurred at about 7.0 km altitude, reached altitudes around 10–12 km and influenced the aerosol size distribution at a distance more than 350 km downwind. This study indicates that even a relatively weak volcanic eruption may produce an observable effect on the aerosol properties at the regional scale. The impact of secondary sulphate particles on the aerosol size distribution at Lampedusa is discussed, and estimates of the clear sky direct aerosol radiative forcing are derived. Daily shortwave radiative forcing efficiencies are calculated with the LibRadtran model. They are estimated between −39 and −48 W m−2 AOD−1 at the top of the atmosphere, and between −66 and −49 W m−2 AOD−1, at the surface, with the variability in the estimates mainly depending on the aerosol single scattering albedo. These results suggest that sulphate particles played a large role, while the contribution by ash particles was small in the volcanic plume arriving at Lampedusa during this event.

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Seasonal cloud-radiative forcing over land and ocean derived from ERBE satellites

10.2514/6.1991-52 ◽

1991 ◽

Author(s):

EDWIN HARRISON ◽

GARY GIBSON

Keyword(s):

Radiative Forcing ◽

Cloud Radiative Forcing

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Improvement of Cloud Radiative Forcing and Its Impact on Weather Forecasts

The Open Atmospheric Science Journal ◽

10.2174/1874282301307010001 ◽

2013 ◽

Vol 7 (1) ◽

pp. 1-13 ◽

Cited By ~ 4

Author(s):

Qiying Chen ◽

Xin-Zhong Liang ◽

Min Xu ◽

Tiejun Ling ◽

Julian X.L. Wang

Keyword(s):

Radiative Forcing ◽

Cloud Radiative Forcing ◽

Weather Forecasts

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Reduction of surface radiative forcing observed from remote sensing data during global COVID-19 lockdown

Atmospheric Research ◽

10.1016/j.atmosres.2021.105729 ◽

2021 ◽

pp. 105729

Author(s):

Usman Mazhar ◽

Shuanggen Jin ◽

Muhammad Bilal ◽

Md. Arfan Ali ◽

Rehana Khan

Keyword(s):

Remote Sensing ◽

Radiative Forcing ◽

Remote Sensing Data ◽

Sensing Data

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Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7155-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 7155-7170 ◽

Cited By ~ 26

Author(s):

Y. Liu ◽

W. Wu ◽

M. P. Jensen ◽

T. Toto

Keyword(s):

Radiative Forcing ◽

Climate Models ◽

Cloud Fraction ◽

Shortwave Radiation ◽

Cloud Radiative Forcing ◽

Analytical Expression ◽

Cloud Albedo ◽

Annual Variations ◽

Hourly Data ◽

Radiation Parameterizations

Abstract. This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997–2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

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Relationship between Shortwave Cloud Radiative Forcing and Local Meteorological Variables Compared in Observations and Several Global Climate Models

Journal of Climate ◽

10.1175/jcli3875.1 ◽

2006 ◽

Vol 19 (17) ◽

pp. 4344-4359 ◽

Cited By ~ 12

Author(s):

Markus Stowasser ◽

Kevin Hamilton

Keyword(s):

Relative Humidity ◽

Vertical Velocity ◽

Radiative Forcing ◽

Large Scale ◽

Climate Models ◽

Grid Point ◽

Global Climate Models ◽

Coupled Models ◽

Cloud Radiative Forcing ◽

Cloud Forcing

Abstract The relations between local monthly mean shortwave cloud radiative forcing and aspects of the resolved-scale meteorological fields are investigated in hindcast simulations performed with 12 of the global coupled models included in the model intercomparison conducted as part of the preparation for Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). In particular, the connection of the cloud forcing over tropical and subtropical ocean areas with resolved midtropospheric vertical velocity and with lower-level relative humidity are investigated and compared among the models. The model results are also compared with observational determinations of the same relationships using satellite data for the cloud forcing and global reanalysis products for the vertical velocity and humidity fields. In the analysis the geographical variability in the long-term mean among all grid points and the interannual variability of the monthly mean at each grid point are considered separately. The shortwave cloud radiative feedback (SWCRF) plays a crucial role in determining the predicted response to large-scale climate forcing (such as from increased greenhouse gas concentrations), and it is thus important to test how the cloud representations in current climate models respond to unforced variability. Overall there is considerable variation among the results for the various models, and all models show some substantial differences from the comparable observed results. The most notable deficiency is a weak representation of the cloud radiative response to variations in vertical velocity in cases of strong ascending or strong descending motions. While the models generally perform better in regimes with only modest upward or downward motions, even in these regimes there is considerable variation among the models in the dependence of SWCRF on vertical velocity. The largest differences between models and observations when SWCRF values are stratified by relative humidity are found in either very moist or very dry regimes. Thus, the largest errors in the model simulations of cloud forcing are prone to be in the western Pacific warm pool area, which is characterized by very moist strong upward currents, and in the rather dry regions where the flow is dominated by descending mean motions.

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Transmission of solar radiation through clouds on melting glaciers: a comparison of parameterizations and their impact on melt modelling

Journal of Glaciology ◽

10.3189/002214311796406013 ◽

2011 ◽

Vol 57 (202) ◽

pp. 367-381 ◽

Cited By ~ 42

Author(s):

Francesca Pellicciotti ◽

Thomas Raschle ◽

Thomas Huerlimann ◽

Marco Carenzo ◽

Paolo Burlando

Keyword(s):

Solar Radiation ◽

Air Temperature ◽

Radiative Forcing ◽

Model Performance ◽

Horizontal Resolution ◽

Swiss Alps ◽

Cloud Radiative Forcing ◽

Correct Definition ◽

Diurnal Range ◽

The Impact

AbstractWe explore the robustness and transferability of parameterizations of cloud radiative forcing used in glacier melt models at two sites in the Swiss Alps. We also look at the rationale behind some of the most commonly used approaches, and explore the relationship between cloud transmittance and several standard meteorological variables. The 2 m air-temperature diurnal range is the best predictor of variations in cloud transmittance. However, linear and exponential parameterizations can only explain 30–50% of the observed variance in computed cloud transmittance factors. We examine the impact of modelled cloud transmittance factors on both solar radiation and ablation rates computed with an enhanced temperature-index model. The melt model performance decreases when modelled radiation is used, the reduction being due to an underestimation of incoming solar radiation on clear-sky days. The model works well under overcast conditions. We also seek alternatives to the use of in situ ground data. However, outputs from an atmospheric model (2.2 km horizontal resolution) do not seem to provide an alternative to the parameterizations of cloud radiative forcing based on observations of air temperature at glacier automatic weather stations. Conversely, the correct definition of overcast conditions is important.

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