Airborne in-situ measurements of transported mineral dust aerosols in the Mediterranean region 1 Cyrielle Denjean *, Paola Formenti, Claudia Di Biagio, Servanne Chevaillier, Sylvain Triquet, Noel Grand, Pascal Zapf - LISA, * TROPOS Benjamin Torres, Luc Blarel - LOA Thierry Bourrianne, Gérault Momboisse - CNRM Karine Sellegri, Evelyn Freney, Alfons Schwarzenbock - LaMP Marc Mallet - LA

Scientific objectives Describe the vertical profile of mineral dust aerosols in the Western Mediterranean Characterize the physical, chemical and optical properties of transported mineral dust aerosols Comparison with properties observed in the source regions 2

3 Algeria Tunisia Granada Minorca Corsica Lampedusa F30 F31 F29 F33F34 F35-36 F38-39 F41-42 F32 Vertical profiles Backward trajectories Source regions ADRIMED airborne campaign 14 June-04 July 2013

Aerosol instrumentation

5 Aerosol transport above the boundary layer

6 Changes in size distribution within the elevated layers Dust clearly transported above ~3000 m

7 Volume distribution in the elevated layers

Concentration of the fine mode variable, related to different concentrations of anthropogenic particles Si/Al=2.6 V/Si=0.05 Si/Al=2.5 V/Si=0.02 Si/Al=2.5 V/Si=0.008 Si/Al=2.6 V/Si= Volume distribution in the elevated layers

Coarse mode centered between 8 and 21 µm in diameter 9 Volume distribution in the elevated layers

10 How vary the volume distribution after transport ?

11 Evolution of the volume median diameter with the residence time

Variability of single scattering albedo (z > 3500 m asl)

Range of variability in African source regions (not necessarily the right ones) Formenti et al, 2011; Schladitz et al., 2009; Redmond et al., 2010

Tunisia: 2 days of transport (F35) Algeria: 4 days of transport (F42) Changes in size distribution within the elevated layers 14

Physico-chemical properties in the elevated layers Si/Al = Fe/Ca = V/Si = Si/Al = 2.55 Fe/Ca = 0.59 V/Si =

Physico-chemical properties in the elevated layers Si/Al = 2.8 Fe/Ca = ND V/Si = No sampling Si/Al = Fe/Ca = V/Si = Si/Al = 2.55 Fe/Ca = 0.59 V/Si =

Differences in the optical properties of elevated layers F33 F34 F41 F38 F42 F35 17

Conclusions and perspectives Large variability of vertical transport of mineral dust in the Western Mediterranean Dust transported above ~ 1500 m asl, in layers of varying size distribution, mixing state and optical properties Layers above ~3000m asl exhibit coarse mode particles and SSA(530nm) similar as those in source regions Layers between ~1500 and ~3000 m asl might be mixtures of mineral dust and pollution Finalize the study of the chemical composition Finalize the analysis of the PLASMA data Need modelling to trace back the origin of mineral dust Paper in preparation 18

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F29F30 F31F32 F34 F35 F38 F41 F42 20

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Z > 1.6 km Tau = 0.08 Z > 1.6 km Tau = 0.14 Differences in the optical properties Tunisia: 2 days of transport (F35) Algeria: 4 days of transport (F42) 22

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France Spain AlgeriaTunisia Italia Cagliari Corsica Granada Lampedusa Minorca

Mineral dust transport towards the Central and Western Mediterranean basin MODIS, 6 October 2001 MODIS, 19 August MODIS, 22 March 2000 MODIS, 30 October 2001

26 Intense radiative effect Lampedusa Direct radiative effect (Wm -2 ) (daily average) di Sarra et al., JGR, 2011 Lampedusa Clear sky Mineral dust Central Mediterranean Solaire Infrarouge Total

Which are the optical properties of mineral dust in the Western Mediterranean? Meloni et al., Juillet 16 Juillet Profil mesuré  (500 nm) = 0.227,  = 0.08,  0 = 0.96* "Prior to 14 July the air mass passed over the central Sahara, and large dust particles were present mainly above 1.5 km"  (500 nm) = 0.227,  = 0.698,  0 = 0.88* "The air mass arriving at Lampedusa on 16 July had spent the last 1–2 days over North- Western Africa, previously originating from the North Atlantic and Europe, and the aerosol was presumably a mixture of continental/maritime and dust particles." 27

 Aircraft: SAFIRE ATR-42 Base airport: Cagliari (Italy) Flight altitude: ~ m Max aircraft endurance: 4h  Flight operations: tests flights 16 scientific flights  Flight strategy: High level exploration Vertical soundings ≠ straight levelled runs within aerosol layer ATR-42 take-off at Lampedusa 28 ADRIMED airborne campaigns from 14 June to 04 July 2013