Sensitivity of Arctic ozone loss to stratospheric H₂O

Abstract

[1] Likely causes of a future increase in stratospheric H 2 O are a rise in tropospheric CH 4 and H 2 leakages from an increased integration of hydrogen into the energy supply system. Here we evaluate the impact of potential future stratospheric H 2 O increases on Arctic ozone loss by comparing ozone loss proxies based on two different mechanisms of chlorine activation. In particular, the H 2 O dependence of the volume of air is analyzed where temperatures are low enough to form nitric acid trihydrate, denoted as V PSC , and for Cl activation on liquid sulfate aerosols, denoted as V ACl . We show that V ACl increases faster than V PSC with increasing H 2 O mixing ratios in the altitude range of 400 K to 550 K potential temperature. As a consequence, the additional ozone column loss is expected to be most pronounced for cold winters and large H 2 O increases and to be significantly higher when V ACl is used as a proxy. Citation: Feck, T., J.-U. Grooß, and M. Riese (2008)

The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

“…It is expected that when this technology comes into wide use, it will lead to leakage of H 2 into the atmosphere, which may lead to considerably increased atmospheric H 2 levels. This may affect the atmosphere's oxidative capacity and stratospheric ozone levels (Schultz et al, 2003;Warwick et al, 2004;Tromp et al, 2003;Feck et al, 2008). A number of global H 2 budget estimates have been made (Novelli et al, 1999;Hauglustaine and Ehhalt, 2002;Sanderson et al, Bousquet et al, 2011;Pieterse et al, 2011Pieterse et al, , 2012.…”

Impact of a possible future global hydrogen economy on Arctic stratospheric ozone loss

“…This study has been assessed to be unrealistic due to the high leakage rate assumed. 1,2,4,6,47 In contrast, Warwick et al 4 (2004) used only a 5% leakage rate, but the same assumption about the production rates. A scenario proposed by Schultz et al 2 (2003) assumes that only 50% of current fossil-fuel-based technologies will be replaced by hydrogen and estimate a leakage rate between 3% and 10%.…”

“…Because of the uncertainties discussed above, in most studies the impact of a future hydrogen-based economy on the atmosphere is analyzed using scenarios reflecting low, intermediate, and/or very high (worst-case) hydrogen emission rates. 2,3,6,56,57 Fig . 2 shows the range of projected hydrogen production rates with the ''IIASA-SRES B1-H2'' scenario as a clear upper limit.…”

“…The latter scenario is regarded as more realistic compared to the previous scenarios and indicates that H 2 at the Earth's surface is raised to 1.1 ppmv. 2,6 To estimate a reliable magnitude of future hydrogen production in a hydrogen-based economy, the future economic and population growth will have to be taken into account. A scenario considering the future hydrogen production until 2100 ''IIASA-SRES B1-H2'' performed by the International Institute for Applied Systems Analysis (IIASA) is based on the ''IIASA-SRES B1'' simulation published by the Intergovernmental Panel on Climate Change (IPCC).…”

“…However, H 2 leakages caused by a possible future global hydrogen economy [1][2][3][4][5][6][7][8] could yield a significant increase in stratospheric water vapor concentrations. 9 An increase of stratospheric water vapor has, in turn, an impact on surface climate and the stratospheric ozone layer, which is of societal relevance.…”