Long-range transport pathways of tropospheric source gases originating in Asia into the northern lower stratosphere during the Asian monsoon season 2012

Abstract

Abstract. Global simulations with the Chemical

A comprehensive overview of the climatological composition of the Asian summer monsoon anticyclone based on 10 years of Aura Microwave Limb Sounder measurements

“…Detrainment in monsoon outflow plumes and subsequent long‐range transport in the upper troposphere export pollution from the ASM region to the Middle East, Africa, the Mediterranean, Europe, North America, and the Southern Hemisphere [e.g., Scheeren et al , ; Jiang et al , ; Liang et al , ; Barret et al , ; Lawrence and Lelieveld , ; Rogal et al , ; Vogel et al , , , ; Müller et al , ; Rauthe‐Schöch et al , ]. The monsoon circulation plays a key role in stratosphere‐troposphere exchange during northern summer [e.g., Chen , ; Dunkerton , ; Dethof et al , ].…”

“…Monsoon‐induced horizontal advection of extratropical stratospheric air into the tropical tropopause region (in‐mixing) wanes in October [e.g., Konopka et al , ; Ploeger et al , ; Abalos et al , ], although a residual imprint of its cumulative effects is still evident in the ozone distributions at 390 and 410 K (Figures and S8). The anticyclonic vortex breaks up, and air parcels formerly confined inside it are released and spread along the subtropical westerly jet, from which isentropic filaments subsequently carry monsoon air into the northern middle and high latitudes; substantial horizontal transport into the tropics also occurs, such that the entire Northern Hemisphere UTLS is gradually flooded with monsoon air masses as they irreversibly mix into the background air [ Ploeger et al , ; Vogel et al , , ]. A small amount of cross‐equatorial ASM outflow reaches into the southern midlatitudes as well [ Rogal et al , ; Ploeger et al , ; Vogel et al , ].…”

MIPAS IMK/IAA carbon tetrachloride (CCl4) retrieval and first comparison with other instruments

“…This pattern was also seen in HCFC-22 (Chirkov et al, 2016) and could be linked to the Asian monsoon. Calculations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) by Vogel et al (2016) show that there indeed exists a mechanism which can produce local maxima in the upper troposphere in 2-D distributions of source gases. So, the monsoon might offer an explanation for the patterns seen in CCl 4 around these atmospheric regions as well.…”

Water vapor increase in the northern lower stratosphere by the Asian monsoon anticyclone observed during TACTS/ESMVal campaigns

“…These different artificial tracers are freshly emitted every 24 h in the boundary layer and their concentrations in the atmosphere 25 represents the airmass contributions from the respective source regions. For more details see Vogel et al (2015Vogel et al ( , 2016. Vogel et al (2015) showed that the emission tracers for India and eastern China are correlated to AURA-MLS (Livesey et al, 2011) satellite measurements of potential vorticity (PV), O 3 , and CO.…”

“…This tracer marks young air masses that are confined during summer in the AMA and air masses from southeast Asia and the tropical Pacific Ocean influenced by the large-scale flow around the anticyclone in the UTLS. All other source regions can be neglected, since it is shown in Vogel et al (2016), that these regions do not significantly contribute to flooding of the lower stratosphere with young tropospheric air masses in summer and autumn 5 2012.…”