The UV-visible absorption cross-sections of IONO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;

Mössinger, J.; Rowley, D. M.; Cox, R. A.

doi:10.5194/acpd-2-765-2002

Cited by 3 publications

(3 citation statements)

References 14 publications

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“…The kinetics for the photolytic Reactions (R2), and (R6), as well as for Reaction (R4) are updated from Bösch et al (2003) through the JPL-2006 recommendation. IONO 2 photolysis (Reaction R7) has been subject of a recent study by Joseph et al (2007) implying that IONO 2 photolysis can be an order of magnitude slower than currently recommended by the study of Mössinger et al (2002) merged into JPL-2006. Further, Kaltsoyannis and Plane (2008) suggest that IONO 2 could rapidly react with I implying a reduction of the IONO 2 lifetime.…”

Section: Modelling Inorganic Iodine Chemistrymentioning

confidence: 99%

Constraints on inorganic gaseous iodine in the tropical upper troposphere and stratosphere inferred from balloon-borne solar occultation observations

Butz¹,

Bösch²,

Camy‐Peyret³

et al. 2009

Preprint

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Abstract. We report upper limits of IO and OIO in the tropical upper troposphere and stratosphere inferred from solar occultation spectra recorded by the LPMA/DOAS (Limb Profile Monitor of the Atmosphere/Differential Optical Absorption Spectroscopy) payload during two stratospheric balloon flights from a station in Northern Brazil (5.1° S, 42.9° W). In the tropical upper troposphere and lower stratosphere, upper limits for both, IO and OIO, are below 0.1 ppt. Photochemical modelling is used to estimate the compatible upper limits for the total gaseous inorganic iodine burden (Iy) amounting to 0.09 to 0.16 (+0.10/−0.04) ppt in the tropical lower stratosphere (21.0 km to 16.5 km) and 0.17 to 0.35 (+0.20/−0.08) ppt in the tropical upper troposphere (16.5 km to 13.5 km). In the middle stratosphere, upper limits increase with altitude as sampling sensitivity decreases. Our findings imply that the amount of gaseous iodine transported into the stratosphere through the tropical tropopause layer is small and that iodine-mediated ozone loss plays only a minor role for stratospheric photochemistry. However, photochemical modelling uncertainties are large and iodine might be transported into the stratosphere in particulate form.

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Section: Modelling Inorganic Iodine Chemistrymentioning

confidence: 99%

Constraints on inorganic gaseous iodine in the tropical upper troposphere and stratosphere inferred from balloon-borne solar occultation observations

Butz¹,

Bösch²,

Camy‐Peyret³

et al. 2009

Preprint

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“…7, For the yield, see Davis et al [1996]. 8, The recently measured IONO 2 cross section from Mössinger et al [2002] is used. 9, Absorption cross section according to Rowley et al [1999].…”

Section: Adopted Chemistry Of Stratospheric Iodinementioning

confidence: 99%

“…At stratospheric temperatures, the rate coefficient for reaction (R10) is uncertain by a factor of 2, i.e., for p = 100 mbar, and T = 220 K, the error limits given by DeMore et al [1997] suggest a rate coefficient in the range of 2.3 to 8.5 × 10 −12 cm 3 /s with a recommended value of 4.6 × 10 −12 cm 3 /s. Here the recently measured IONO 2 spectrum from Mössinger et al [2002] is taken, and the combined uncertainties of the cross section and actinic flux is taken into account by tuning its photolysis rate by ±50% in the model. Evidently, the combined uncertainties of the formation reaction (R10) and photolysis determine the IONO 2 /IO ratio with the lower photolysis rate and the upper limit of reaction (R10) determining the inferred I y upper limits.…”

Section: Modeling Stratospheric Iodine Chemistrymentioning

confidence: 99%

Upper limits of stratospheric IO and OIO inferred from center‐to‐limb‐darkening‐corrected balloon‐borne solar occultation visible spectra: Implications for total gaseous iodine and stratospheric ozone

Bösch

2003

J. Geophys. Res.

118

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[1] We report upper limits of lower stratospheric IO (inferred lowest values: 0.10 ppt, 0.07 ppt, and 0.06 ppt at 20, 15, and 12.5 km, respectively) and OIO (inferred lowest values: 0.10 ppt, 0.06 ppt, and 0.04 ppt at 20, 15, and 12.5 km, respectively) inferred from balloon-borne solar occultation UV/visible spectroscopy. The spectra were recorded during a series of Laboratoire de Physique Moléculaire et Applications/ differential optical absorption spectroscopy (LPMA/DOAS) balloon flights that were conducted at different geophysical conditions, i.e., inside the Arctic winter vortex, at midlatitudes, and at high latitudes in spring, summer, and fall. Photochemical modeling that accounts for the iodine partitioning during the observations allows us to infer upper limits of total inorganic gas-phase iodine (I y ), i.e., I y (<20 km) of 0.10 ± 0.02 ppt and 0.07 ± 0.01 ppt, taking into account and neglecting OIO photolysis, respectively. For the middle stratosphere, the inferred upper limits of total I y are larger because of the smaller detection sensitivity there. These observations suggest that either much less iodine enters the stratosphere than the amount expected from the stratospheric entry level iodine concentrations (primarily the tropical upper troposphere) or it resides in other minor gaseous species or, eventually, in a nongaseous, i.e., particulate, form in the stratosphere. The implications of our iodine measurements for stratospheric ozone are also briefly assessed using a two-dimensional model. For the assumed loading of 0.1 ppt I y the modeled ozone reduction was small compared to a model run without iodine, with a maximum decrease of around 1% in midlatitudes to high latitudes when OIO photolysis is included. (3334); KEYWORDS: solar occultation spectroscopy, iodine chemistry, stratospheric ozone, center-to-limb-darkening correction, differential optical absorption spectroscopy Citation: Bösch, H., C. Camy-Peyret, M. P. Chipperfield, R. Fitzenberger, H. Harder, U. Platt, and K. Pfeilsticker, Upper limits of stratospheric IO and OIO inferred from center-to-limb-darkening-corrected balloon-borne solar occultation visible spectra: Implications for total gaseous iodine and stratospheric ozone,

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Reaction of phenylperoxy radicals with NO2 at 298 K

Jagiella

Zabel

2007

Phys. Chem. Chem. Phys.

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In the present work, phenylperoxy radicals were generated by stationary 254 nm photolysis of iodobenzene and nitrosobenzene in the presence of O(2) and NO(2) at 298 K and a total pressure of 1 bar (M = N(2)). Experiments were performed on time scales of seconds or minutes in a temperature controlled photoreactor made of quartz (v = 209 L). Major gas phase products identified and quantified in situ by long-path IR absorption include N(2)O(5), NO, HONO, HNO(3), CO, and o-nitrophenol. In addition, evidence is presented for the formation of an aerosol consisting of p-nitrophenol. The occurrence of N(2)O(5) as a major product in both reaction systems, the strong loss of NO(2) in the iodobenzene system and the comparison of measured product distributions with the results of numerical model calculations suggest that the reaction C(6)H(5)O(2) + NO(2) --> C(6)H(5)O + NO(3), k(5)occurs in both photolysis systems, a major part of the NO(3) being scavenged as N(2)O(5). The results of ab initio calculations imply that proceeds via a short-lived peroxynitrate intermediate. In the photolysis of nitrosobenzene-NO(2)-O(2)-N(2) mixtures, NO and NO(2) compete for C(6)H(5)O(2) radicals. Comparison of measured and modelled product distributions allows to set a lower limit of k(5) > 1 x 10(-12) cm(3) molecule(-1) s(-1) at 298 K. This lower limit is consistent with the assumption that k(5) is equal to the high pressure recombination rate constant of RO(2) + NO(2) --> RO(2)NO(2) reactions, i.e. with k(5) approximately 7 x 10(-12) cm(3) molecule(-1) s(-1) at 298 K, 1bar.

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The UV-visible absorption cross-sections of IONO<sub>2</sub>

Cited by 3 publications

References 14 publications

Constraints on inorganic gaseous iodine in the tropical upper troposphere and stratosphere inferred from balloon-borne solar occultation observations

Constraints on inorganic gaseous iodine in the tropical upper troposphere and stratosphere inferred from balloon-borne solar occultation observations

Upper limits of stratospheric IO and OIO inferred from center‐to‐limb‐darkening‐corrected balloon‐borne solar occultation visible spectra: Implications for total gaseous iodine and stratospheric ozone

Reaction of phenylperoxy radicals with NO2 at 298 K

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