1. Eric BOURRIANNE LPC2E - CNRS, ORLEANS
Characterization of the size distribution and nature of the particles detected by the LOAC aerosol counters under tropospheric pressurized balloons
Eric BOURRIANNE
LPC2E - CNRS, ORLEANS

2. LOAC under BPCL for ChArMEx
BPCL : Boundary Layer Pressurized Balloons (Quasi-Lagrangian measurements) 12 flights have been performed from Minorca and Ile du Levant
SOP-2
SOP-1
We focus here on 4 different situations :
Background measurements
Sand events
Salt detection
Carbon detection

3. ChArMEx-S1-B76 – 2 July 2013 Background condition
-o- BPCL
-o- BLD
ascent
Background condition
Changes in the balloon altitude due to the day-night transition
Presence of large particles
(> 20 µm)

4. Background condition in the first part of the flight
ALADIN model 2 July 2013, 18UT
Undefined
ALADIN model 2 July 2013, 42UT
Background condition in the first part of the flight
Sand measurements for the second par of the flight
(Non-lagrangian measurements due to variation of the balloon altitude)

5. Cross-comparison between BPCL and BLD (meteo balloon) measurements at same altitude
Size distribution
Speciation
Very good agreement for the size distribution and for the indication of the nature of the aerosols (no homogenous nature in this case)

6. ChArMEx-S1-B74 – 16 June 2013 – Sand event
-o- BPCL
-o- BLD
Presence of large particles (up to 50 µm)
No strong evolution of the size distribution during the flight

7. The LOAC speciation seems to indicate mixture of sand and salt.
ALADIN model, 16 June 2013, 12UT
The LOAC speciation seems to indicate mixture of sand and salt.

8. Cross-comparison between BPCL and BLD (meteo balloon) measurements at same altitude
Size distribution
Speciation
Good agreement between BPCL and BLD
Speciation : Sand for particles > 2µm, sand and/or salt for particles < 2µm

9. ChArMEx-S1-B75 – 17 June 2013 – Sand event
-o- BPCL
-o- BLD
Presence of large particles (up to 50 µm)
No strong evolution of the size distribution during the flight

10. ChArMEx-S2-B51– 22and23 July 2013 –
-o- BPCL
-o- BLD
low altitude flight (400m)
Detection of salt particles for all sizes
Constant concentrations all along the flight

11. ChArMEx-S1-B80– 28 June 2013
Possible detection of the biomass burning plume

12. Conclusions Main results :
Very good agreement between the BPCL and BLD LOAC measurement at similar time and altitude
LOAC as detected different natures of particles depending on the flights
Detection of large sand particles even after several day of transport
No sedimentation detected during the BPCL flights