arctic atmospheric chemistry: the polar sunrise experiments (pse) jan w. bottenheim 1, paul b....
DESCRIPTION
Relationship between ozone and bromine From: Barrie et al., 1988TRANSCRIPT
Arctic Atmospheric Chemistry: the Polar Sunrise Experiments (PSE)
Jan W. Bottenheim1, Paul B. Shepson2, Jose D. Fuentes3, Leonard A. Barrie4
1Meteorological Service of Canada, Toronto, ON, Canada2Purdue University, West Lafayette, IN, USA3University of Virginia, Charlottesville, VA, USA4WMO, Geneva, Switzerland
Chronology of PSEs:
1988: first PSE
1992, 2000: major campaigns
Yearly small, dedicated campaigns
Relationship between ozone and bromine
From: Barrie et al., 1988
Br + O3 -> BrO + O2
BrO + BrO-> 2 Br + O2
223 2 HOBrOkBrOk
dtOd
BrO + BrO limiting
BrO + HO2 -> HOBr
HOBr + Br- -> 2 Br
From: Foster et al., 2001
From: Hoenninger and Platt, 2002
0
26
28
30
32
34
36
38
40
42
44
ppbv
Seibert et al. Analysis - Alert - O3 (ppbv)00, 12 UTC - 240 Hours
1989 - 2000 : January - February
0
5
10
15
20
25
30
35
40
45
50
ppbv
Seibert et al. Analysis - Alert - O3 (ppbv)00, 12 UTC - 240 Hours
1989 - 2000 : March - April
From: Richter et al., 1998
GOME satellite data
Frequency of depletion episodes is increasing (0.7 % y-1),evidence of climate change?
Most episodes occur where surface temperature is < -20 0C
Frost flower growth is efficient over new sea-ice, at a rate inversely proportional to temperature
Gas-Phase FormaldehydePolar Sunrise Experiment 1998
Day of Year
50 60 70 80 90 100 110[H
CH
O],
ppt
0
50
100
150
200
250
300
350
400
450
500
550
X Axis 2
35860 35880 35900
[Ozo
ne],
ppb
0
10
20
30
40
50
60
50 60 70 80 90 100 110
J HC
HO, s
-1
0.05.0e-61.0e-51.5e-52.0e-52.5e-5
JHCHO
[HCHO], O3 = 0
[HCHO], low O3
[HCHO], O3 > 40 ppb
[Ozone]
The HCHO lifetime changes from ~3 months in the dark, to 0.5 days in sunlightFrom: Sumner and Shepson, 1999
Radical SourceRadical Source
HCHOHCHO ++ hh ••HH HOHO22••
HOHO22•• ++ BrOBrO•• HOBrHOBr ++ OO22
HOBr(HOBr(aqaq) + Br ) + Br - - + H + H++ BrBr22((aqaq) ) Br Br22((gg) + ) + hh 2 2 ••BrBrBromine Radical SinkBromine Radical Sink
••BrBr ++ OO33 BrOBrO•• ++ OO22
BrOBrO•• ++ BrOBrO•• 2 2 ••BrBr ++ OO22
••BrBr + + HCHO HCHO HBrHBr ++ HCOHCO••
Role of Formaldehyde in Ozone Destruction
PSE92
0
100
200
300
400
500
600
700
800
900
12-Apr 13-Apr 14-Apr 15-Apr 16-Apr
Mxi
ing
ratio
(ppt
v)
Ozone (*20) NOy NOx PAN
O3, *20
NOy
PAN
NOx
Vertical HONO profile at SST, 10:00-14:30, 4/24/00.
-10
10
30
50
70
90
110
0 10 20 30 40 50 60 70
HONO, ppt
Hei
ght/D
epth
, cm
Courtesy: X. Zhou, SUNYA
Courtesy: Schroeder and Steffen, MSC
Atmospheric Mercury at Alert 1995-2000
Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01
GEM
(ng
m-3
)
0
1
2
3
4
5
Courtesy: Anlauf and Hayden, MSC
Similarly, ozone depletion in spring is anannually recurring phenomenon
(for a graphic representation contact Dr. K.G. Anlaufat the Meteorological Service of Canada, Toronto, Ontario, Canada)
Conc. (ng/ m3)0.5 1.50.0 1.0 2.0
Heigh
t (cm
)
0
20
40
60
80
100
120
1405/ 8/ 00 14:505/ 8/ 00 15:505/ 8/ 00 16:505/ 8/ 00 17:505/ 8/ 00 19:05
Conc. (ng/ m3)0.5 1.50.0 1.0 2.0
Heigh
t (cm
)
0
20
40
60
80
100
120
140
5/ 8/ 00 14:505/ 8/ 00 15:505/ 8/ 00 16:505/ 8/ 00 17:505/ 8/ 00 19:05
From: Steffen et al., 2002
TGM at Ice Camp
Height (m
)
[O 3] in ppbv0 2 4 6
0.01
0.1
1
10
27 Apr: 4 to 12 h
28 Apr 6 to 16 h
5 May: 0 to 10 h
Ozone Profiles at Ice Camp
Fuentes, unpublished
From: Albert et al., 2002
Ozone fluxes and deposition velocity (Vd)Ice Camp during 26 April to 8 May 2000
Flux
(mol
ec m
-2 s
-1)
[O3],
ppb
v
0
5
10
15Ozone Flux[Ozone]
Time of Day (Hours)4 8 12 16 20 24
Vd (c
m s
-1)
0.000
0.003
0.006
x 1011
0
1
2
3
Vd = 0.002 ± 0.005 cm s-1
Courtesy: Strong and Fuentes
From: Bottenheim et al., 2002
Some future experiments• Detailed chemistry profiles of the lower atmosphere (< 100 m)
• Role of frost flowers on chemical processing
• Laboratory experiments devoted to the heterogeneous chemistry on frozen seawater surfaces
• Other? (discuss at meeting on Saturday evening)
• Three-dimensional studies to investigate the climate impact of ozone depletion
`