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CU Aircraft High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS)

Status

Status: 
Operational (Currently fully integrated with EESI-ToF-MS)
Operated By: 
PI

HR-AMS instrument installed on the NASA DC-8 for ATom-1

Principle: The CU aircraft version of the Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) detects non-refractory submicron aerosol composition by impaction on a vaporizer at 600°C, followed by electron ionization and time-of-flight mass spectral analysis. Size-resolved composition can be quantified by measuring the arrival times of the aerosol at the vaporizer.

Aircraft Operation: (1 min cycles, can be adjusted to meet mission goals):
46 s total concentration measurements (1 s resolution, can be increased to up to 10 Hz upon request)
5 s speciated size distribution measurements (with improved S/N detection due to ePToF acquisition)
9 s Background + Overhead
Higher accuracy due to flight day calibrations using built-in system
Custom pressure controlled inlet with confirmed performance up to 45 kft

Real Time Data Products: 
PM1 Aerosol Mass Concentrations:
Organic aerosol (OA) , SO4, NO3, NH4, Chloride 
OA Chemical Markers: f44 (Secondary OA), f57 (hydrocarbon-like OA), f60 (biomass burning OA), f82 (isoprene epoxide-SOA), other fx upon request

More Advanced Products:
- PM1 Seasalt, ClO4, total I, total Br, MSA concentrations
- O/C, H/C, OA/OC, OSc
- Particle organic nitrates (pRONO2)
- Ammonium Balance, estimated pH
- OA components by positive matrix factorization (PMF)
- Particle eddy covariance fluxes of all species
- Speciated Aerosol size distributions

Detection Limits (1s, ng sm-3), (1 min, ng sm-3) from start of the flight (due to custom cryopump):
Sulfate: 40, 15
Nitrate: 15, 6
Ammonium: 3, 1
Chloride: 30, 12
OA: 200, 80
For detailed OA analysis, longer averaging (3-30 s, depending on OA concentration) is needed. A 1 min product is hence provided as well.

 

Instrument Type: 
Spectrometer (in situ)
Measurements: 
Organic Aerosol, NH4, NO3, SO4, NR-Cl, Br-, Iodine, seasalt, MSA, ClO4, pRONO2
Aircraft: 
DC-8 - AFRC, C-130 - NSF, Gulfstream III - LaRC
Recent Missions: 
AEROMMA (DC-8 - AFRC); ASIA-AQ (DC-8 - AFRC); FIREX-AQ (DC-8 - AFRC); ATom (DC-8 - AFRC); KORUS-AQ (DC-8 - AFRC); WINTER (C-130 - NSF)
Complete mission list:
Point(s) of Contact: 
Jose-Luis Jimenez (POC; PI), Pedro Campuzano-Jost (Co-I), Douglas A. Day (Mgr), Hongyu Guo (Mgr), Demetrios Pagonis (Mgr), Dongwook Kim (Mgr), Guy Symonds (Mgr), Melissa Morris (Mgr), Seonsik Yun (Mgr)