Annual cycle of aerosol direct radiative effect over southeast Italy and sensitivity studies

Tafuro, A. M.; Kinne, Stefan; Tomasi, F. De; Perrone, M. R.

doi:10.1029/2006jd008265

Cited by 35 publications

(28 citation statements)

References 44 publications

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“…These SSA values are close to those observed in southern Spain (0.86-0.90) by Horvath et al (2002). Over southeastern Italy, Tafuro et al (2007) reported a value of 0.94 during summertime corresponding to anthropogenic particles. Finally, polluted particles transported over the Mediterranean basin also have relatively low values as reported by Markowicz et al (2002) over Crete (0.87) and by Di (0.79-0.83) over Lampedusa for two cases (25 and 27 May 1999) of "aged" anthropogenic aerosols originating from Europe.…”

Section: Mallet Et Al: Overview Of the Charmex/adrimed Summer 201supporting

confidence: 66%

“…Numerous studies have documented the AOD for polluted anthropogenic Mediterranean aerosols at a local scale over southeastern France Roger et al, 2006), Spain Alados-Arboledas et al, 2003, the western Mediterranean (Lyamani et al, 2015), Greece (Chazette and Liousse, 2001;Gerasopoulos et al, 2003), the Greek island of Crete (Fotiadi et al, 2006), and Italy (Tafuro et al, 2007;Ciardini et al, 2012). Under polluted conditions, they report low to moderate AOD values ranging between 0.1 and 0.5 (at visible wavelengths).…”

Section: Mallet Et Al: Overview Of the Charmex/adrimed Summer 201mentioning

confidence: 99%

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Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

et al. 2016

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Abstract. The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region (ADRIMED) project during the Mediterranean dry season over the western and central Mediterranean basins, with a focus on aerosol-radiation measurements and their modeling. The SOP-1a took place from 11 June to 5 July 2013. Airborne measurements were made by both the ATR-42 and F-20 French research aircraft operated from Sardinia (Italy) and instrumented for in situ and remote-sensing measurements, respectively, and by sounding and drifting balloons, launched in Minorca. The experimental setup also involved several ground-based measurement sites on islands including two ground-based reference stations in Corsica and Lampedusa and secondary monitoring sites in Minorca and Sicily. Additional measurements including lidar profiling were also performed on alert during aircraft operations at EARLINET/ACTRIS stations at Granada and Barcelona in Spain, and in southern Italy. Remote-sensing aerosol products from satellites (MSG/SEVIRI, MODIS) and from the AERONET/PHOTONS network were also used. Dedicated meso-scale and regional modeling experiments were performed in relation to this observational effort. We provide here an overview of the different surface and aircraft observations deployed during the ChArMEx/ADRIMED period and of associated modeling studies together with an analysis of the synoptic conditions that determined the aerosol emission and transport. Meteorological conditions observed during this campaign (moderate temperatures and southern flows) were not favorable to producing high levels of atmospheric pollutants or intense biomass burning events in the region. However, numerous mineral dust plumes were observed during the campaign, with the main sources located in Morocco, Algeria and Tunisia, leading to aerosol optical depth (AOD) values ranging between 0.2 and 0.6 (at 440 nm) over the western and central Mediterranean basins. One important point of this experiment concerns the direct observations of aerosol extinction onboard the ATR-42, using the CAPS system, showing local maxima reaching up to 150 M m −1 within the dust plume. Non-negligible aerosol extinction (about 50 M m −1 ) has also been observed within the marine boundary layer (MBL). By combining the ATR-42 extinction coefficient observations with absorption and scattering measurements, we performed a complete optical closure revealing excellent agreement with estimated optical properties. This additional information on extinction properties has allowed calculation of the dust single scattering albedo (SSA) with a high level of confidence over the western Mediterranean. Our results show a moderate variability from 0....

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Section: Mallet Et Al: Overview Of the Charmex/adrimed Summer 201supporting

confidence: 66%

Section: Mallet Et Al: Overview Of the Charmex/adrimed Summer 201mentioning

confidence: 99%

Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

et al. 2016

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“…Although sensitivity studies demonstrated a relatively weak impact of the aerosol vertical distribution on radiative forcing at the surface or at clear-sky conditions (e.g. Tafuro et al, 2007), some impact can be expected under cloudy-skies for ToA DRE a , as (already slightly) absorbing aerosols (e.g. dust and pollution) above lower placed clouds (e.g.…”

Section: Aerosol Vertical Distributionmentioning

confidence: 99%

“…(Paltridge and Platt, 1976) are used. A discussion on the accuracy of individual AERONET retrievals is reported in Dubovik et al ( , 2002 and it is also recalled in Tafuro et al (2007). The number of measurements/month that have been properly weighted to retrieve monthly aerosol optical and microphysical properties at the selected AERONET sites, are given in Table 1.…”

Section: Surface Propertiesmentioning

confidence: 99%

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Monthly-averaged anthropogenic aerosol direct radiative forcing over the Mediterranean based on AERONET aerosol properties

et al. 2008

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Abstract. The all-sky direct radiative effect by anthropogenic aerosol (DRE a ) is calculated in the solar (0.3-4 µm) and infrared (4-200 µm) spectral ranges for six Mediterranean sites. The sites are differently affected by pollution and together reflect typical aerosol impacts that are expected over land and coastal sites of the central Mediterranean basin. Central to the simulations are aerosol optical properties from AERONET sun-/sky-photometer statistics for the year 2003. A discussion on the variability of the overall (natural + anthropogenic) aerosol properties with site location is provided. Supplementary data include MODIS satellite sensor based solar surface albedos, ISCCP products for high-mid-and low cloud cover and estimates for the anthropogenic aerosol fraction from global aerosol models. Since anthropogenic aerosol particles are considered to be smaller than 1 µm in size, mainly the solar radiation transfer is affected with impacts only during sun-light hours. At all sites the (daily average) solar DRE a is negative all year round at the top of the atmosphere (ToA). Hence, anthropogenic particles produce over coastal and land sites of the central Mediterranean a significant cooling effect. Monthly DRE a values vary from site to site and are seasonally dependent as a consequence of the seasonal dependence of available sun-light and microphysical aerosol properties. At the ToA the monthly average DRE a is −(4±1) W m −2 during spring-summer (SS, AprilSeptember) and −(2±1) W m −2 during autumn-winter (AW, October-March) at the polluted sites. In contrast, it varies between −(3±1) W m −2 and −(1±1) W m −2 on SS and AW, respectively at the less polluted site. Due to atmospheric absorption the DRE a at the surface is larger than at the ToA. At the surface the monthly average DRE a varies between the most and the least polluted site between −(7±1) W m −2 and −(4±1) W m −2 during SS, and between −(4±3) W m −2Correspondence to: M. R. Perrone (perrone@le.infn.it) and −(1±1) W m −2 during AW. The DRE a at infrared wavelengths is positive but negligible, especially at the ToA (<0.3 W m −2 ). The average of DRE a monthly-means referring to all sites has allowed getting a ToA-and sfc-DRE a yearly-mean value of −(3±2) and −(5±3) W m −2 , respectively at solar wavelengths. Last data, even if refer to a particular year, indicate that the radiative energy-balance of Central Mediterranean land and coastal sites is quite affected by anthropogenic particles.

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Estimation of mineral dust direct radiative forcing at the European Aerosol Research Lidar NETwork site of Lecce, Italy, during the ChArMEx/ADRIMED summer 2013 campaign: Impact of radiative transfer model spectral resolutions

Barragán

Romano

Sicard

et al. 2016

J. Geophys. Res. Atmos.

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A field campaign took place in the western and central Mediterranean basin on June–July 2013 in the framework of the ChArMEx (Chemistry‐Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr/)/ADRIMED (Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region, http://adrimed.sedoo.fr/) project to characterize the aerosol direct radiative forcing (DRF) over the Mediterranean. This work focuses on the aerosol DRF estimations at Lecce (40.33°N; 18.11°E; 30 m above sea level) during the Saharan dust outbreak that affected southern Italy from 20 to 24 June 2013. The Global Atmospheric Model (GAME) and the Two‐Stream (TS) model were used to calculate the instantaneous aerosol DRF in the short‐wave (SW) and long‐wave (LW) spectral ranges, at the surface and at the top of the atmosphere (TOA). The main differences between the two models were due to the different numerical methods to solve the radiative transfer (RT) equations and to the more detailed spectral resolution of GAME compared to that of TS. 167 and 115 subbands were used by GAME in the 0.3–4 and 4–37 µm spectral ranges, respectively. Conversely, the TS model used 8 and 11 subbands in the same spectral ranges, respectively. We found on 22 June that the SW‐DRFs from the two models were in good agreement, both at the TOA and at the surface. The instantaneous SW‐DRFs at the surface and at the TOA varied from −50 to −34 W m−2 and from −6 to +8 W m−2, respectively, while the surface and TOA LW‐DRFs ranged between +3.5 and +8.0 W m−2 and between +1.7 and +6.9 W m−2, respectively. In particular, both models provided positive TOA SW‐DRFs at solar zenith angles smaller than 25° because of the mixing of the desert dust with anthropogenic pollution during its transport to the study site. In contrast, the TS model overestimated the GAME LW‐DRF up to about 5 and 7.5 times at the surface and at the TOA, respectively, when the dust particle contribution was largest. The low spectral resolution of the real (n) and imaginary (k) refractive index values was mainly responsible for the LW‐DRF overestimates of the TS model. However, we found that the “optimization” of the n and k values at 8.75 and 11.5 µm was sufficient in this study to obtain a satisfactory agreement between the LW‐DRFs from the two models, both at the TOA and at the surface. The impact of the spectral dependence of the water vapor absorption coefficients on the estimation of the flux without aerosol has also been addressed. Paper results did not reveal any significant impact due to the different numerical methods used by the two models to solve the RT equations.

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Annual cycle of aerosol direct radiative effect over southeast Italy and sensitivity studies

Cited by 35 publications

References 44 publications

Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

Monthly-averaged anthropogenic aerosol direct radiative forcing over the Mediterranean based on AERONET aerosol properties

Estimation of mineral dust direct radiative forcing at the European Aerosol Research Lidar NETwork site of Lecce, Italy, during the ChArMEx/ADRIMED summer 2013 campaign: Impact of radiative transfer model spectral resolutions

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