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ASCOS Planned Aerosol Instrumentation Aboard Oden
Douglas Orsini
Jost HeintzenbergLeibniz Institute for Tropospheric Research
Leipzig, Germany
Motivation
To contribute to measured physical and chemical properties of the marine aerosol ( especially Dp < 1 um) and to target biological particles
Three instruments:
1. DMPS
1. VTDMA
1. Water Cyclone
DMPS
Differential Mobility Particle Sizer
Goal: To measure the aerosol size distribution
Particle size range: 3 nm < Dp < 800 nm
Sample Flow Rate: 1 lpm
Measurement Rate: Semi-continuous every 10 min.
VTDMA
Volatility Tandem Differential Mobility Particle Analyzer
Goal: To infer composition and mixing state based on reference volatility measurements
1. Select particle size (30 nm < Dp < 300 nm; 1 lpm)
2. Heat the selected aerosol size ( 3 temperatures possible )
3. Re-measure the aerosol size
VTDMA
Volatility Tandem Differential Mobility Particle Sizer
Some reference temperatures:
• ~ 150 - 200 oC ( H2SO4, (NH4)HSO4, (NH4)2SO4 )
• ~ 300 oC ( volatile OC )
• ~ 600 - 800 oC ( less volatile OC + NaCl )
• ~ ? ( viruses, bacteria, cell material )
- fine marine aerosols exist capable of surviving at 300oC (Clarke, 1999, Clarke et al., 2003)
- little data on volatility of viruses and bacteria as ambient particles
To Be Determined: selected sizes + heating temperatures
Time permitting: prelimin. tests of bubbled microlayer water to determine temperatures.
Water Cyclone
Collects bulk aerosol into liquid (insoluble + soluble)
Sample flow rate: 17 lpm continuous
Liquid sample flow: 24 hours: 100 - 1000 ml of sample liquid for analysis
Consumables: 0.02 ultrapure water : 5 liters / day
Liquid Sample Analysis
Water Cyclone
On-Board
Biological Enumeration
Storage for Post Analysis
Chemical and Biological
Water Cyclone
On-Board Biological Enumeration
Ship-board analysis of aerosol sample: (pending fluorescence microscope)
1. Concentrate sample liquid on .02 filter substrate (start with 24 hr. sample)
2. Stain with Sybr-Green/Gold which binds to nucleic acid
3. Enumerate biological particles (based on known protocol) with microscope
Post Analysis
Water Cyclone
microlayer liquid & bubbled microlayer
aerosol collection into liquid
Coordinate similar sample preparation and storage protocols
e.g.: TOC
Basic ions
Amino acids
EPS gels
flow cytometry
.
.
.
.
What is possible for consistent analysis ?
microlayer liquid & bubbled microlayer
aerosol collection into liquid
fogwateraerosol
impactors
Coordinate parallel sample storage and protocols
An upper Dp size cut-off ?
e.g. :
Water Cyclone
PM10 aerosol
impactor
Dp < 100 nmcollection into liquid
Counting Protocol for Marine Samples