Formation of hydroxyl radical from the photolysis of frozen hydrogen peroxide (Journal of Physical Chemistry A (2005) 109A (6269))

Full text of DOI:10.1021/jp800491n

J. Phys. Chem. A 2008, 112, 2747-2748
2747
ADDITIONS AND CORRECTIONS
2
005, Volume 109A
Table 2. Most importantly, our originally reported values for
Alert, Nunavut were based on an incorrect temperature (268 K
instead of the new, and more typical, value of 243 K) and an
actinic flux for the wrong day. Correcting for these errors, the
Liang Chu and Cort Anastasio*: Formation of Hydroxyl
Radical from the Photolysis of Frozen Hydrogen Peroxide
•
new rate constants (and rates) of OH formation from photolysis
Page 6269. There was an error in the original version of
Figure 5, where the scales of the x-axes (wavelength) in the
top two panels did not match the scale of the bottom panel.
This is corrected in the new version shown below. The figure
caption, and its discussion in the text, are correct and remain
unchanged.
-
of HOOH and NO3 are 2.1 and 9.8 times lower, respectively,
than the original values. There were also some minor mistakes
in the modeled actinic fluxes at the other three sites. Fixing
these problems changes the originally reported rate constants
•
and rates for OH formation by -34% to +30%. The correct
values are shown in the table below. Despite these errors, the
conclusions of the original paper are unchanged.
Page 6270. There were a few mistakes in the original
calculations of the rate constants and rates of OH formation in
•
•
-
Figure 5. Action spectra for OH formation from the photolysis of HOOH and NO
3
on ice. The top panel shows molar absorptivities of aqueous
hydrogen peroxide (solid line) and nitrate (dashed line) at 274 K as well as the modeled midday, actinic flux on the summer solstice at Neumayer,
•
Antarctica (70.7 °S, 8.3 °W; dotted line; ref 52). The middle panel shows quantum yields of OH from the photolysis of HOOH (squares; this work)
and nitrate (circles; ref 10) in ice pellets at 263 K. Symbols show data for pellets illuminated with 313 and 334 nm radiation, and the lines represent
the recommended quantum yields at 263 K for each chromophore at λ > 290 nm. The bottom panel shows the wavelength dependence of the rate
•
constants for OH formation from photolysis of HOOH (solid line) and nitrate (dashed line). The area under each curve is the total rate constant
•
•
for OH formation from that chromophore (j(if OH)) at Neumayer under the conditions described above.

2748 J. Phys. Chem. A, Vol. 112, No. 12, 2008
Additions and Corrections
•
TABLE 2: Calculated Rates of Formation of OH from the Photolysis of Snowpack Hydrogen Peroxide and Nitrate at Sites in
the Arctic and Antarctic
•
•
typical surface snowpack
rate constant for OH formation,
rate of OH formation,
concn of chromophore i (µM)c
j(if OH)SUN (10
•
-6 -1
s
)
d
R(if OH)SUN (10 M s-1)
•
-12
fraction of OH
from HOOH
locationa
dateb
HOOH
NO
-
HOOH
NO
-
HOOH
NO
3
-
3
3
Alert, Nunavut
Summit, Greenland
South Pole
Mar 21
Jun 21
Dec 21
6
18
10
4.8
4.2
4
1.6
1.4
0.27
4.3
1.9
0.0060
0.22
0.068
0.28
1.6
77
19
0.025
0.87
0.11
0.39
0.98
0.99
0.99
0.98
Neumayer, Antarctic Dec 21
4.8
23
a
atitudes and longitudes of sampling sites: Alert (82.5 °N, 62.3 °W), Summit (72.6 °N, 38.5 °W), South Pole (90 °S), and Neumayer (70.7 °S,
b
8
.3 °W). Calculations are for midday (solar noon) on the specified date. Temperatures used for calculations at Alert, Summit, South Pole, and
Neumayer were 243, 263, 253, and 268 K, respectively. Values are from Anastasio and Jordan (estimated HOOH) and Toom-Sauntry and Barrie
for Alert, Hutterli et al. and Dibb et al. for Summit, Wolff et al. for South Pole. At Neumayer, we used an average of the typical 0-5 mm values
of Jacob and Klockow (6.0 µM) and that of Riedel (3.5 µM) for HOOH and the average value of Mulvaney et al. (1.9 µM) and Wolff et al.
0.8 µM) for NO
for the snow surface and ozone columns of 306-309 Dobson units. Altitudes used for Alert, Summit, South Pole and Neumayer were 63, 3200,
800, and 45 m, respectively.
c
8
46
7
47
48
4
9
50
51
48
-
d
52
(
3
. The actinic fluxes used in our calculations are from the NCAR TUV model using a wavelength-independent albedo of 0.93
5
3
54
2
10.1021/jp800491n
Published on Web 02/29/2008