Quantification of water vapour transport from the Asian monsoon to the stratosphere

Matthias Nützel,Aurélien Podglajen,Felix Ploeger,Hella Garny

doi:10.5194/egusphere-egu2020-9165

Abstract

&lt;p&gt;&lt;span&gt;We use multiannual simulations with the chemistry-transport model CLaMS (Chemical Lagrangian Model of the Stratosphere) to analyze water vapour transport from the Asian monsoon region to the stratosphere. Further, we make comparisons of the transport characteristics from the Asian monsoon to the stratosphere with those of other source regions (e.g. from the tropics). In addition, we characterize the transport efficiency of the monsoon region compared to other source regions and bring our results into context with previous studies, which have focused on water vapour transport from the Asian monsoon to the stratosphere. These analyses are complementing the previously published work by Ploeger et al. (2017), who have analyzed mass transport from the Asian monsoon anticyclone to the stratosphere. &lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;The presented findings have been recently published in Atmospheric Chemistry and Physics (N&amp;#252;tzel et al., 2019).&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;span&gt;

Highlights

Atmospheric water vapour is a key greenhouse gas (e.g. Held and Soden, 2000; Schmidt et al, 2010; Müller et al, 2016)
As proposed by Brewer (1949), tropical tropopause layer (TTL) temperatures strongly influence water vapour abundances in the stratosphere. This can be seen by the so-called water vapour tape recorder (Mote et al, 1996, see Fig. 3), i.e. an annual seesaw of positive and negative water vapour anomalies that ascends in the tropical pipe (Plumb, 1996) and is related to the seasonal cycle of TTL temperatures (e.g. Yulaeva et al, 1994)
E.g. by Bannister et al (2004) and Wright et al (2011), have used tagging approaches for stratospheric water vapour; the water tagging employed here is suited for our research aims, since it allows a decomposition of water origins consistent with the model treatment of water transport and removal through freeze-drying

Summary

Introduction

Atmospheric water vapour is a key greenhouse gas (e.g. Held and Soden, 2000; Schmidt et al, 2010; Müller et al, 2016). Despite the extremely low average water vapour mixing ratios in the stratosphere (considerably below 10 μmol mol−1; see e.g. Hegglin et al, 2013, their Fig. 4) compared to tropospheric abundances (see e.g. Sherwood et al, 2010, their Fig. 2), changes in stratospheric and tropical tropopause layer (TTL; Fueglistaler et al, 2009) humidity can noticeably impact Earth’s surface climate (e.g. Solomon et al, 2010; Riese et al, 2012). As proposed by Brewer (1949), TTL temperatures strongly influence water vapour abundances in the stratosphere. This can be seen by the so-called water vapour tape recorder (Mote et al, 1996, see Fig. 3), i.e. an annual seesaw of positive and negative water vapour anomalies that ascends in the tropical pipe (Plumb, 1996) and is related to the seasonal cycle of TTL temperatures (e.g. Yulaeva et al, 1994)

Objectives

Results

Discussion

Conclusion