vacc - volatility aerosol composition and concentration
DESCRIPTION
VACC - Volatility Aerosol Composition and Concentration. VACC – Science Summary. Is CN mixed into cloud from above and/or below? Out of cloud deep profiles Porpoise through area to look for variation in CN Characterise CN concentration and composion below and above cloud - PowerPoint PPT PresentationTRANSCRIPT
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
VACC - Volatility Aerosol Composition and Concentration
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
VACC – Science Summary
• Is CN mixed into cloud from above and/or below?– Out of cloud deep profiles – Porpoise through area to look for variation in CN– Characterise CN concentration and composion below
and above cloud
• If isolated cloud available characterise CN concentration and composition of inflow and outflow
– orbits at different levels or straight and level legs perpendicular to wind. (depends on the extent of the cloud)
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
VACC – flight leg requirements• CPC – N (R > 5 nm)
• 10 Hz data• flow controlled at 3 l/min all levels• No special flight requirements
• SMPS – dN/dR (5 nm < R < ~200 nm)• Scan every 2.5 minutes• Sample flow controlled at 1 l/min all levels• Sheath flow controlled at 10 l/min all levels• Flight requirements:
• Constant altitude for duration of scan• Preferably straight but can deal with wide angle turn/orbit
• OPC – Volatility – constant temperature – dN/dR (50 nm < R < 1 µm)• 1 Hz data• Sample flow controlled at 0.12 l/min at all levels• No special flight requirements
• OPC – Volatility – scanning temperature - dN/dR (50 nm < R < 1 µm)• Scan every 8 minutes• Sample flow controlled at 0.12 l/min at all levels• Flight requirements:
• Constant altitude for duration of scan• Preferably straight but can deal with wide angle turn/orbit
• Summary• Flight speed as slow as possible• Altitude profiles of CPC and OPC-volatility-set temperature obtainable• For SMPS or OPC-volatility – scanning temperature: require straight and level or level in slow turn flight legs.• Minimum operational pressure 500 mb ~6000m• Cannot operate in cloud
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
B047 – 09:22 (UTC)
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
No particles R > 0.55μm
75°C100°C
130°C160°C
200°C
230°C
260°C300°C
Sample can be considered dry.
Ammonium Hydrogen Sulphate
Ammonium SulphateSodium Hydrogen Carbonate
Ammonium Nitrate
MSA / Sulphuric acid
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UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
External/Internal Mixing.
T
a
T
b
R1 R2
N2
N1
R1 R2
N2
N1
R1
N
R1
N1
N N = N1 + N2
T a
T b
T T c
T d
T T e
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
N
R1 R2
2N