1. Lead Fluxes Andreas Held, Caroline Leck, Ian Brooks, Barbara Brooks, Sarah Norris

2. SOURCES TRANSPORTDRY DEPOSITION open sea sea-ice lead TRANSFORMATION surface albedo cloud albedo CCN scattering & absorption WET DEPOSITION Simplified Arctic Aerosol Life Cycle

3. Open Lead Flux System 1)Gill sonic anemometer 2)CLASP optical particle counter (0.24 < D p < 18.5 µm) 3)CPC 3760A condensation particle counter (D p > 11 nm) 4)LICOR 7500 CO 2 /H 2 O analyzer 5)MOXA datalogger CLASP units LiCOR 7500 sonic anemometer Examine the capacity of the open leads to emit particles to the air by eddy covariance measurements: fully battery operated (low power consumption) located close to the ice edge ~2 m above the surface, near bubble camera site

4. Neutral Case z/L=0 z 0 =0.001 m, σ v / u* = 2 z m =1, 2, 3 m wind 10 20 50 100 m Photo: H.J. Zwally, NASA Goddard Footprint Analysis of Open Lead Flux System FSAM (Schmid, 1994)

5. Pump Sensing head 25 cm 16 channels - 0.24 to 18.5  m diameter Flow rate 3 l/min – high sampling statistics allows 10 Hz temporal resolution Compact (25 x 8 x 6 cm) – allows collocation with sonic anemometer, short inlet tube and low flow distortion, & installation in balloon instrument package and on buoy CLASP Instrument

6. Total particle number concentration for D p > 11 nm Flow rate 1.5 l/min – good counting statistics 10 Hz sampling, but actual time response is slower Provides additional size bin from 10 nm to 240 nm in combination w/ CLASP Condensation Particle Counter

7. Spray Sampler for Filter Collection and Electron Microscopy Stockholm prototype: artificial bubble generation below water surface adjustable bubble diameter to generate film/jet droplets spray collection w/ filter sampler for off-line analysis spray collection on EM grid for electron microscopy free floating on water height adjustment of bubbler & sampler