Closure of the total hydrogen budget of the northern extratropical lower stratosphere

Hurst, D. F.; Dutton, G. S.; Romashkin, P. A.; Wamsley, P. R.; Moore, F. L.; Elkins, James W.; Hintsa, E. J.; Weinstock, E. M.; Herman, R. L.; Moyer, E. J.; Scott, David C.; May, R. D.; Webster, C. R.

doi:10.1029/1998jd100092

Cited by 42 publications

(63 citation statements)

References 32 publications

(15 reference statements)

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“…These values differ from our findings in the box model approach. Our estimated γ H2O is smaller and our γ H2 is larger than estimated by Hurst et al (1999). As noted before, by using observational data it is not possible to distinguish between H 2 from 20 the troposphere and H 2 produced by H from CH 4 , which results in this rather low net production of H 2 .…”

contrasting

confidence: 38%

“…The current study focuses on stratospheric water vapour (SWV), which is by itself an influential driver of climate change. SWV, for example, induces a reduction of using a specifically introduced CH 4 tracer (by applying the CH4 submodel) according to: calculated by Hurst et al (1999) and the yield of le Texier et al (1988) also do not agree well in the lower stratosphere, which can indeed be explained by the indistinguishable inputs from H 2 and CH 4 oxidation in observations as stated before. Yet, this does also indicate that the yield from CH 4 oxidation itself must be even lower than suggested by the net production, which is calculated based on observations.…”

Section: Introductionmentioning

confidence: 82%

“…A different approach than the first two presented ones to determine γ H2O in the stratosphere is to use the fact that the vertical 25 profile of the H content in terms of atoms is fairly constant above the tropopause (see Fig. 12 …”

Section: Ratio Of H:h 2 :H 2 Omentioning

confidence: 99%

“…In further sensitivity simulations with CAABA, OH is initialized with the reference from EMAC multiplied with constants 25 and kept constant throughout the simulation. This introduces an additional prescribed hydrogen carrying species, which introduces or withdraws hydrogen to or from the system.…”

Section: Sensitivity With Respect To Ohmentioning

confidence: 99%

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Investigating the yield of H2O and H2 from methane oxidation in the stratosphere

Frank¹,

Jöckel²,

Gromov³

et al. 2018

Preprint

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Abstract. An important driver of climate change is stratospheric water vapour (SWV), which in turn is influenced by the oxidation of atmospheric methane (CH 4 ). In order to parameterize the production of water vapour (H 2 O) from CH 4 oxidation, it is often assumed that the oxidation of one CH 4 molecule yields exactly two molecules of H 2 O. However, this assumption is based on an early study, which also gives evidence, that this is not true at all altitudes.In the current study we re-evaluate this assumption with a comprehensive systematic analysis using a state-of-the art Chemistry- 5Climate model (CCM), namely the ECHAM/MESSy Atmospheric Chemistry (EMAC) model, and present three approaches to investigate the yield of H 2 O and hydrogen gas (H 2 ) from CH 4 oxidation. We thereby make use of Module Efficiently Calculating the Chemistry of the Atmosphere (MECCA) in a box model and global model configuration. Furthermore, we use the kinetic chemistry tagging technique (MECCA-TAG) to investigate the chemical pathways between CH 4 , H 2 O and H 2 , by being able to distinguish hydrogen atoms stemming from CH 4 and other sources. 10We apply three approaches, which all agree that assuming a yield of 2 overestimates the production of H 2 O in the lower stratosphere (calculated as 1.5-1.7). Additionally, transport and subsequent photochemical processing of longer-lived intermediates raise the local yield values in the upper stratosphere and lower mesosphere above 2 (maximum > 2.2). In the middle and upper mesosphere, the influence of loss and recycling of H 2 O increases, making it a crucial factor in the parameterization of the yield of H 2 O from CH 4 oxidation. An additional sensitivity study with the Chemistry As A Boxmodel Application (CAABA) shows

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contrasting

confidence: 38%

Section: Introductionmentioning

confidence: 82%

Section: Ratio Of H:h 2 :H 2 Omentioning

confidence: 99%

Section: Sensitivity With Respect To Ohmentioning

confidence: 99%

See 2 more Smart Citations

Investigating the yield of H2O and H2 from methane oxidation in the stratosphere

Frank¹,

Jöckel²,

Gromov³

et al. 2018

Preprint

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“…Stars: Balloon-borne MIPAS data inside the Arctic vortex at 68 • N (Stowasser et al, 1999 Hanson and Robinson (1989). More recent in situ measurements indicated higher values of 1.94±0.27 (Dessler et al, 1994) 1996), 1.973±0.003 (Hurst et al, 1999), and 1.975±0.030 (Zöger et al, 1999) Yang and Tung (1996), other numbers are model results. Consider moreover, that the influence of in-situ H 2 O production due to CH 4 oxidation on δD(H 2 O) is small below ∼30 km, too.…”

Section: 4)mentioning

confidence: 75%

Modelling the budget of middle atmospheric water vapour isotopes

Zahn¹,

Franz

Bechtel

et al. 2006

Atmos. Chem. Phys.

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Abstract.A one-dimensional chemistry model is applied to study the stable hydrogen (D) and stable oxygen isotope ( 17 O, 18 O) composition of water vapour in stratosphere and mesosphere. In the troposphere, this isotope composition is determined by "physical" fractionation effects, that are phase changes (e.g. during cloud formation), diffusion processes (e.g. during evaporation from the ocean), and mixing of air masses. Due to these processes water vapour entering the stratosphere first shows isotope depletions in D/H relative to ocean water, which are ∼5 times of those in 18 In the stratosphere the known mass-independent fractionation (MIF) signal in O 3 is in a first step transferred to the NO x family and only in a second step to HO x and H 2 O. In contrast to CO 2 , O( 1 D) only plays a minor role in this MIF transfer. The major uncertainty in our calculation arises from poorly quantified isotope exchange reaction rate coefficients and kinetic isotope fractionation factors.

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OBSERVATIONS FOR CHEMISTRY (IN SITU) | Water Vapor Sondes

Weinstock

2003

Encyclopedia of Atmospheric Sciences

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Closure of the total hydrogen budget of the northern extratropical lower stratosphere

Cited by 42 publications

References 32 publications

Investigating the yield of H<sub>2</sub>O and H<sub>2</sub> from methane oxidation in the stratosphere

Investigating the yield of H<sub>2</sub>O and H<sub>2</sub> from methane oxidation in the stratosphere

Modelling the budget of middle atmospheric water vapour isotopes

OBSERVATIONS FOR CHEMISTRY (IN SITU) | Water Vapor Sondes

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Closure of the total hydrogen budget of the northern extratropical lower stratosphere

Cited by 42 publications

References 32 publications

Investigating the yield of H&lt;sub&gt;2&lt;/sub&gt;O and H&lt;sub&gt;2&lt;/sub&gt; from methane oxidation in the stratosphere

Investigating the yield of H&lt;sub&gt;2&lt;/sub&gt;O and H&lt;sub&gt;2&lt;/sub&gt; from methane oxidation in the stratosphere

Modelling the budget of middle atmospheric water vapour isotopes

OBSERVATIONS FOR CHEMISTRY (IN SITU) | Water Vapor Sondes

Contact Info

Product

Resources

About

Investigating the yield of H<sub>2</sub>O and H<sub>2</sub> from methane oxidation in the stratosphere

Investigating the yield of H<sub>2</sub>O and H<sub>2</sub> from methane oxidation in the stratosphere