Influences of Halogen Chemistry on Processing of North American
Pollutant Outflow
University of New Hampshire, Mount Washington Observatory
University of VirginiaUniversity of California, San Diego
University of California, Los AngelesUniversity Heidelberg
Goals• To quantify the influences of halogen radicals on ozone
production/destruction in polluted air along the New England east coast during summer.
• To investigate the influence of nocturnal radical chemistry, i.e. NO3 and N2O5, on halogen levels.
• To investigate the role of halogens in the production and chemical evolution of aerosols over the Gulf of Maine.
• To assess potential implications of the outflow on the chemistry in the MBL over the Gulf of Maine.
Location: Shoals Marine Laboratory, Appledore Island
Instrument Overview• O3, CO, NO, VOC (PTRMS), CO2, CH4 through AIRMAP• LP- and MAX-DOAS: O3, NO2, SO2, HCHO, NO3, BrO, IO, OIO, I2• Inorganic gaseous chlorine: HCl* (primarily HCl) and Cl* (including
Cl2 + HOCl), by tandem mist chambers• soluble trace gases (HNO3, NH3, SO2, HCl, HCOOH, and CH3COOH)
by second tandem mist chamber system • Total gaseous inorganic Br and I by daytime/nighttime filter packs • C2-C10 hydrocarbons, C1-C5 alkylnitrates, halocarbons • Organic and inorganic ionic constituents (NO3
–, SO42–, CH3SO3
–, Cl–, Br–, HCOO–, CH3COO–, C2O42–, Na+, K+, Mg2+, and Ca2+) and total Na, Cl, Br, and I in daytime/nighttime size segregated aerosol samples
• Particle number-size distributions (6 to 800 nm) at 40% RH by multistaged particle sizing spectrometer and DMA
• Photolysis rates by spectroradiometer
7/12/2004 08:007/12/2004 12:00
7/12/2004 16:007/12/2004 20:00
7/12/2004 24:00
0.0
5.0x1016
1.0x1017
1.5x1017
0
2
4
6
8
10
12
LP D
OA
S N
O2 (
ppb)
MA
X-D
OA
S N
O2 S
CD
(mol
ec/c
m2 )
UTC
MAX-DOASElevation
1o
3o
5o
15o
Multi Axis DOAS
LP-DOAS / AIRMAP Data Overview
7/9/20047/10/2004
7/11/20047/12/2004
7/13/20047/14/2004
7/15/20047/16/2004
7/17/20047/18/2004
7/19/2004
05
10152002040608002401230
30
600.00.20.40.60.8
0246810
200300
NO
2 (ppb
)
EDT
O3 (p
pb)
HCH
O (p
pb)
AIRMAP
SO
2 (ppb
)
N
O3 (p
pt)
HO
NO
(ppb
)
NO
(ppb
) C
O (p
pb)
Water Soluble Gases7000
6000
5000
4000
3000
2000
1000
0
ppt
v
204202200198196194192190188Julian Day, 2004 (UT)
HClws HNO3 CH3COOH HCOOH NH3
Day 188 = 7/6/2004
SMPS Aerosol Data
Ultrafine Particle CPC
Transition on 7/15/04
7/14/2004 00:00 7/15/2004 00:00 7/16/2004 00:00 7/17/2004 00:00 7/18/2004 00:000
5
100
2040608002401230
5x10-3
1x10-20
90180270360
0246810
200300
051015
NO
2 (ppb
)
EDT
O3 (p
pb)
HCH
O (p
pb)
AIRMAP
SO
2 (ppb
)
J(N
O2) (
s-1)
Win
d D
ir
NO
(ppb
) C
O (p
pb)
Win
d S
peed
Toluene at the Isles of Shoals and Thompson Farm
EDT7/13 7/15 7/17
Tolu
ene
(ppt
v)
0
200
400
600
800
TF IOS
EDT7/13 7/15 7/17
2-B
uON
O2
(ppt
v)
0
2
4
6
8
10
12
14
TF IOS
2-BuONO2 at the Isles of Shoals and Thompson Farm
EDT7/13 7/15 7/17
C2C
l 4 (pp
tv)
0
10
20
30
40
50
IOS
C2Cl4 at the Isles of Shoals
Back-TrajectoriesClean Period
8am EDT 7/15/04Polluted Nocturnal Period
9pm EDT 7/15/04
Halocarbons at the Isles of Shoals
EDT7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18
CH
3I, p
ptv
0
1
2
3
4
5
CH
Br3 (pptv)
0
10
20
30
40
CH3I CHBr3
Morning 7/15
Halocarbons at the Isles of Shoals
EDT7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18
CH
2Br 2
(ppt
v)
0
1
2
3
4
5
6
7
8
CH
Br3 (pptv)
0
10
20
30
40CH2Br2CHBr3
CHBr3 / CH2Br2 correlation
CH2Br2
0 2 4 6 8
CH
Br 3
0
10
20
30
40
TFIOS
7/14 & 7/15 IOS
Reactive Halogens ?
7/15/2004 06:00 7/15/2004 12:00 7/15/2004 18:0001230
204060800
2
4
05x10-3
1x10-20
90180270360
0123
051015
012
NO
2 (ppb
)
EDT
O3 (p
pb)
Tentative !
AIRMAP
IO (p
pt)
J(N
O2) (
s-1) W
ind
Dir
NO
(ppb
) W
ind
Spee
d
(m/s
) T
ide
(m)
Morning 7/15
CH2ClI in Chromatograms
C2C
l 4
i-PrO
NO
2
CH
2Br 2
CH
BrC
l 2
CH
2ClI
n-P
rON
O2
?
Conclusions• Measurements show periods of clean marine
influence and polluted continental air
• Clean periods (7/14 & 7/15) show elevated halocarbons, tentatively reactive iodine and precursors
• Night of 7/16 the Boston/NYC plume was observed, with high VOC, O3, NOx, NO3, soluble gases, and aerosol
The CHAiOS CrewChemistry of Halogens at the Isles of Shoals
