Title: Aerosol Chemical Composition determined using the PILSIC on the G1 during 2005 MASE
1Aerosol Chemical Composition determined using the
PILS-IC on the G1 during 2005 MASE
- Yin-Nan Lee
- Atmospheric Sciences Division
- Brookhaven National Laboratory
- Stephen Springston, BNL
- Gunnar Senum, BNL
- John Hubbe, PNNL
- John Jayne, Aerodyne
- Mike Alexander, PNNL
- Jian Wang, BNL
- Peter Daum, BNL
- Jim Hudson, DRI
- Atmospheric Science Program Science Meeting
- Oct. 31 - Nov. 1, 2005
2Objectives
- To understand the aerosol-CCN-cloud-precipita
tion system and its radiative effects in a
coastal marine environment by investigating - Aerosol optical properties as a function of size
and chemical composition - Relationship between CCN properties and aerosol
size and chemical composition - Relationship between cloud microphysics and
aerosol properties - Relationship between drizzle formation and cloud
microphysics - Radiative properties of marine stratus and extent
of human influences
32005 Marine Stratus Experiment
- A field campaign in California supported by ARM
and ASP - ARM Mobile Facility - Point Reyes
- SIRPAS Twin Otter Marina
- DOE G1 Rancho Cordova
- G1 conducted 12 research flights between 7/6 and
7/27 - Measurements made on the G1
- Aerosol number concentration, size distribution,
light scattering, light absorption, CCN
concentration and spectrum - Aerosol bulk (PILS-IC) and size resolved (AMS)
chemical composition - Cloud droplet size distribution, liquid water
content - Met and aircraft parameters
4Products of the PILS-IC analysis during 2005 MASE
- Anions Cl-, NO3-, SO42-, CH3SO3-,
formate/acetate, oxalate - Cations Na, NH4, Mg2, K, Ca2
- Time resolution 4.0 min
- Sample integration time 4.0 min nominal
- Limit of detection 0.05 µg m-3
- Measurement uncertainty 7-15
5Distributions of aerosol ionic Species (marine
only)
Na
Cl
NH4
SO4
MSA
NO3
Mg
6Examining the observed compositionregarding
- Sources
- Effects on optical properties
- Possible cloud effects on aerosol measurements
- Organic content, distribution and role
7Total ion concentration and the contribution of
NaCl
Total ion concentration, µg/m3
NaCl mass fraction,
Wind speed, m/s Alt lt 100 m
8Ion and Charge Balance
9Comparison of SSA and seawater composition
10Comparison of NH4 to SO42- and NO3-
11Vertical distributions of O3 and SO2
12Vertical distributions of aerosol ionic species
13Relationship between light scattering coefficient
and pcasp number concentration
14Aerosol light scattering coefficient as a
function of number concentration and NaCl content
15Aerosol light scattering in cloud vs free air
16Relationship among light scattering, number
concentration and light absorption
17Relationship between light scattering coefficient
and ion mass concentration
18Relationship among light scattering, number
concentration and organic concentration
19Correlations of organics and inorganic
ions(cloud free air only)
20Tentative Remarks
- NaCl contributes significantly to aerosol
inorganic ionic mass over the marine environment. - SSA particles are important contributors to light
scattering due primarily to their large sizes. - Inferred organic component comprises an important
portion of the aerosol mass. - Because both particle numbers and the organic
mass were significantly reduced in cloud, organic
aerosol particles appear to play an important
role as CCN.