Lead Fluxes

1
Lead Fluxes

• Andreas Held, Caroline Leck, Ian Brooks,
  Barbara Brooks, Sarah Norris

2
Simplified Arctic Aerosol Life Cycle
cloud albedo
scattering absorption
CCN
TRANSFORMATION
WET DEPOSITION
TRANSPORT
DRY DEPOSITION
SOURCES
surface albedo
open sea sea-ice lead
3
Open Lead Flux System
Examine the capacity of the open leads to emit
particles to the air by eddy covariance
measurements

1. Gill sonic anemometer
2. CLASP optical particle counter
   (0.24 lt Dp lt 18.5 µm)
3. CPC 3760A condensation particle counter (Dp gt 11
   nm)
4. LICOR 7500 CO2/H2O analyzer
5. MOXA datalogger

fully battery operated (low power
consumption) located close to the ice edge 2 m
above the surface, near bubble camera site
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Footprint Analysis of Open Lead Flux System
Neutral Case z/L0 z00.001 m, sv / u 2 zm1,
2, 3 m
FSAM (Schmid, 1994)
10 20 50 100 m
Photo H.J. Zwally, NASA Goddard
5
CLASP Instrument

• 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

6
Condensation Particle Counter

• Total particle number concentration for Dp gt 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

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