Global modelling of H2 mixing ratios and isotopic compositions with the TM5 model
| Autor: | Pieterse, G., Krol, M.C., Batenburg, A.M., Steele, L.P., Krummel, P.B., Langenfelds, R.L., Röckmann, T. |
|---|---|
| Přispěvatelé: | Marine and Atmospheric Research, Afd Marine and Atmospheric Research, Sub Atmospheric physics and chemistry |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Meteorologie en Luchtkwaliteit
atmospheric chemistry WIMEK Meteorology and Air Quality molecular-hydrogen general-circulation model lcsh:QC1-999 lcsh:Chemistry lcsh:QD1-999 photochemical data transport impact tropospheric photolysis rates lowermost stratosphere european photoreactor facility dry deposition parameterization lcsh:Physics |
| Zdroj: | Atmospheric Chemistry and Physics, Vol 11, Iss 14, Pp 7001-7026 (2011) Atmospheric Chemistry and Physics, 11(14), 7001-7026 Atmospheric Chemistry and Physics 11 (2011) 14 |
| ISSN: | 1680-7324 1680-7316 7001-7026 |
| Popis: | The isotopic composition of molecular hydrogen (H2) contains independent information for constraining the global H2 budget. To explore this, we have implemented hydrogen sources and sinks, including their stable isotopic composition and isotope fractionation constants, into the global chemistry transport model TM5. For the first time, a global model now includes a simplified but explicit isotope reaction scheme for the photochemical production of H2. We present a comparison of modelled results for the H2 mixing ratio and isotope composition with available measurements on seasonal to inter annual time scales for the years 2001–2007. The base model results agree well with observations for H2 mixing ratios. For δD[H2], modelled values are slightly lower than measurements. A detailed sensitivity study is performed to identify the most important parameters for modelling the isotopic composition of H2. The results show that on the global scale, the discrepancy between model and measurements can be closed by adjusting the default values of the isotope effects in deposition, photochemistry and the stratosphere-troposphere exchange within the known range of uncertainty. However, the available isotope data do not provide sufficient information to uniquely constrain the global isotope budget. Therefore, additional studies focussing on the isotopic composition near the tropopause and on the isotope effects in the photochemistry and deposition are recommended. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|