Air-sea gas exchange of long-lived semivolatile organic compounds

Air-sea gas exchange of long-lived semivolatile organic compounds & PAH photochemistry / formation of nitro-PAHs G. Lammel, B. Vrana, Z. Kitanovski, P. Kukučka, P. Příbylová, R. Prokeš, P. Shahpoury Max Planck Institute for Chemistry, Multiphase Chemistry Dept, , Mainz, Germany Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, Czech Republic pe es icid st

Formation of NPAHs from PAHs in the marine atmosphere and intercontinental transport ? Site Sample Marine 2012 Cont’l 2013 background polluted all subset(n) (23) (2 a) (2 b) (22) FLT 226 189 330 342 PYR 158 118 245 226 0. 053 <0. 16 0. 36 0. 034 0. 64 0. 22 2. 04 1. 1 (0. 5%) (0. 41%) Primary all (0. 49%) (0. 75%) 8. 0 3. 8 8. 2 15 (3. 5%) (5. 3%) (4. 5%) (4. 4%) 2. 2 0. 87 4. 6 1. 3 (1. 4%) (1. 9%) (0. 6%) Primary and 2 NFLN c secondary Secondary 1 NPYR 2 NFLT d (yield) 2 NPYR ag from impactor PUF samples, p from high-vol (Digitel) QFF samples b samples g: I 6 N 1, I 6 D 1, I 8 D 2, p: H 7 N, H 7 D, H 10 D, H 12 D c samples g: I 1, I 7 N 2, I 8 D 2, p: H 1, H 2, H 9 N, H 10 N, H 12 N d also formed heterogeneously; Jariyasopit et al. EST 2014 e co-eluted with 3 NFLT, assuming c 3 NFLT = 0 Lamm el et al. ACPD 2017

Observed air concentrations at source (Urla /Izmir) and receptor (background site Finokalia /Crete) summer 2012 Izmir Finokalia Tracking of urban influence in air mass history: Time series of urban dose, Du, of samples collected at the receptor site Finokalia /Crete Lammel et al. ACPD 2017

deposition volatilisation RV Urania 27. 8. -12. 9. 2010, air-sea exchange of PAHs Faw (ng m-2 d-2) of fluoranthene, pyrene and retene. Error bars indicate sea water concentration cw

RV Urania 27. 8. -12. 9. 2010, air-sea exchange of PAHs 2 -box model for retene cycling b [µg m-2], part. mass fractions dba/dt = Fem/ha + Fvolbw/ha – a bavdep/ha + kvolcw – (1 - a) k. OHca dbw/dt = w vexpbw/hw – (1 - w) Fvolbw/hw + a bavdep/hw – kocbw Model predicted diffusive air-sea exchange flux, Faw, of retene (ng m-2 d-1; downward upward) for the Eastern Mediterranean (28 -45°N/8 -30°E), hourly means. Data filtered against off-shore winds. 1. 1. 2005 -31. 12. 2010 27. 8. -9. 9. 2010 (Mulder et al. , ACP 2014)

Aegean, Cretan coast July 2012 Volatilisation of POPs from sea surface Mostly Gradient method (eddy covariance) 2 -13 July PHE, ACE, FLT, PYR, Pe. CB, HCB, - and -HCH, PCB 28, -52 and -101 p, p’-DDE Gaseous ↓ ↕ ↑ ACE, FLN, FLT, PYR, Pe. CB, HCB, - and -HCH, PCB 52, BDE 47 Particulate phase ↑ ↓ FLT, PYR, BDE 47, -99 FLT, PYR Sign/direction of flux fluctuates for most substances Lammel et al. ACP 2016

Model predicted concentrations in air and diffusive air-sea exchange flux, Faw, of OCPs, PCBs (pg m-2 d-1; downward upward) for the Aegean (Ta, Tw, hmix) hourly means (Tw AVHRR, hmix ECMWF/FLEXPART). d. MBL = variable Aegean, 6 -10 July 2012, homogeneous advection (1 air mass, northerly advected)

‚Water sampling‘: enrichment of dissolved trace substances in an organic sampling medium i. e. , silicon rubber sheet fixed in a water jet on Iona: pumped through pipe in the moon pool from under keel → time resolution: 1 sample / 3 -5 days Transects across the Black Sea RV Mare Nigrum 2016, unpublished data Vrana et al.

RV Meteor Cape Town → Rio de Janeiro 1 -18 March 2016 Air samples, gaseous and particulate phases: 19 (16× 24 h, 1× 22 h, 2× 12 h = 220 -300 km) + 6 blanks Water samples, dissolved phase: 5 (4× 85 h, 1× 54 h = 800 -1450 km) + 4 blanks

PAH photochemistry - Results and conclusions • NPAHs are formed from PAHs within 6 -30 h (Aegean Sea, summer) • NPAHs go into long-range and intercontinental transport (E Mediterranean, summer) Air-sea gas exchange - Results and conclusions • Air-sea exchange is a source of POPs in air in the remote marine environment of the Mediterranean. During one episode (uniform air mass), the diurnal variation of contaminant concentrations in the marine BL is explained by the combination of atmospheric mixing depth, d. MBL, and diffusive air sea exchange. Volatilisation of pollutants (PAHs, PCBs, OCPs) also during night-time. • The direction of diffusive air-sea exchange of several PAHs and OCPs may fluctuate within days (Castro-Jiménez et al. , 2012; Lammel et al. , 2016), or in response to seasonal trends (Mulder et al. , 2014)

SW monsoon AQABA aims: • NPAH formation / levels in the Persian Gulf ? • anthropogenic POP sources Kairo, Kuwait/Basra/Khoramschar/Abadan ? • direction of air-sea exchange of OCPs in the N Indian Ocean and Arabian Sea under very clean (SW monsoon) conditions ? Requirements: • deploy 1 -2 high-volume air samplers (filter or impactor cascade + PUF plug) 75 kg 2 k. W/220 V on top of a container on the main deck; • ‘water sampling’ in 200 L barrel on deck close to moon pool, water pumped through pipe from immersed pump >1 m under keel, with temperature sensor • space: 1 m lab-type work bench 2 -5 times 15 -30 min per day, personnel: Roman Prokeš on the leg Kuwait-Suez