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

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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