PCASP-100X and FSSP-300 Aerosol Spectrometer Probes
Purpose of Participation
- determine total number concentration and size distribution of aerosol particles in the accumulation and coarse mode size range (in situ measurement) in the dry state (PCASP-100X) and in the ambient state (FSSP-300), determine lateral and vertical distribution of the optically active aerosol in the Arctic troposphere
- estimate humidity related growth of aerosols in the overlap size range of both probes
- contribute to characterization of Arctic aerosol in terms of physical and properties, temporal aerosol evolution, origin and transport pathways
- contribute to closure study by providing data necessary to calculate optical properties from physical properties
Instrument description
Species Number concentration and size distribution of accumulation and coarse mode aerosol particles, in situ
| Species | Aerosols and trace gases |
| Method | The measurement principle of optical aerosol spectrometer probes is based on the detection of light scattered by a single aerosol particle passing through a laser beam. The amount of light scattered is related to the particle size (depending on particle refractive index and particle shape). |
| Quantity primary | PCASP-100X: Number concentration of aerosol particles (dry state) in 15 size bins between 120 nm and 3 µm; |
| FSSP-300: Number concentration of aerosol particles (ambient state) in 31 size bins between 0.3 nm and 20 µm | |
| Quantity secondary | number size distribution, surface size distribution, volume size distribution |
| Measurement range | n/a |
| Altitude range | altitude range of the aircraft (in general: all troposphere and lower stratosphere) |
| Vertical resolution | depends on climb/descend rate of the aircraft, typically >5 m |
| Temporal resolution | depends strongly on aerosol load: 1-20 seconds for total concentration, approx. 10 s up to 5 min for size distribution |
| Operation | operated continuously during flight |
| Precision | depends strongly on counting statistics: ±5-100% |
| Preliminary data | Quicklooks and preliminary data 30 min after flight |
| Final data | 2-6 months |
Specific remarks
- The two aerosol spectrometer probes form part of an extensive aerosol payload on-board the Polar 4 aircraft, which is dedicated to a comprehensive physical aerosol characterization (including complete size distribution). See elsewhere: DMA system, CPSA.
References
Petzold et al., Vertical variability of aerosol properties observed at a continental site during LACE 98, J. Geophys. Res., 107 (D21) 8128 10.1029/2001JD001043, 2002.
Fiebig et al., Optical closure for an aerosol column: method, accuracy, and inferable properties, applied to a biomass burning aerosol and its radiative forcing, J. Geophys. Res., 107 (D21) 8130 10.1029/2000JD000192, 2002.