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@ARTICLE{Vogel:862877,
author = {Vogel, Bärbel and Müller, Rolf and Günther, Gebhard and
Spang, Reinhold and Hanumanthu, Sreeharsha and Li, Dan and
Riese, Martin and Stiller, Gabriele P.},
title = {{L}agrangian simulations of the transport of young air
masses to the top of the {A}sian monsoon anticyclone and
into the tropical pipe},
journal = {Atmospheric chemistry and physics},
volume = {19},
number = {9},
issn = {1680-7324},
address = {Katlenburg-Lindau},
publisher = {EGU},
reportid = {FZJ-2019-03064},
pages = {6007 - 6034},
year = {2019},
abstract = {We have performed backward trajectory calculations and
simulations with the three-dimensional Chemical Lagrangian
Model of the Stratosphere (CLaMS) for two succeeding monsoon
seasons using artificial tracers of air mass origin. With
these tracers we trace back the origin of young air masses
(age <6 months) at the top of the Asian monsoon
anticyclone and of air masses within the tropical pipe (6
months < age <18 months) during summer 2008. The
occurrence of young air masses (<6 months) at the top of the
Asian monsoon anticyclone up to ∼460 K is in agreement
with satellite measurements of chlorodifluoromethane
(HCFC-22) by the Michelson Interferometer for Passive
Atmospheric Sounding (MIPAS) instrument. HCFC-22 can be
considered as a regional tracer for continental eastern Asia
and the Middle East as it is mainly emitted in this
region.Our findings show that the transport of air masses
from boundary layer sources in the region of the Asian
monsoon into the tropical pipe occurs in three distinct
steps. First, very fast uplift in “a convective range”
transports air masses up to 360 K potential temperature
within a few days. Second, air masses are uplifted from
about 360 K up to 460 K within “an upward spiralling
range” within a few months. The large-scale upward spiral
extends from northern Africa to the western Pacific. The air
masses are transported upwards by diabatic heating with a
rate of up to 1–1.5 K per day, implying strong vertical
transport above the Asian monsoon anticyclone. Third,
transport of air masses occurs within the tropical pipe up
to 550 K associated with the large-scale Brewer–Dobson
circulation within ∼1 year.In the upward spiralling range,
air masses are uplifted by diabatic heating across the
(lapse rate) tropopause, which does not act as a transport
barrier, in contrast to the extratropical tropopause.
Further, in the upward spiralling range air masses from
inside the Asian monsoon anticyclone are mixed with air
masses convectively uplifted outside the core of the Asian
monsoon anticyclone in the tropical adjacent regions.
Moreover, the vertical transport of air masses from the
Asian monsoon anticyclone into the tropical pipe is weak in
terms of transported air masses compared to the transport
from the monsoon anticyclone into the northern extratropical
lower stratosphere. Air masses from the Asian monsoon
anticyclone (India/China) contribute a minor fraction to the
composition of air within the tropical pipe at 550 K
$(6 \%),$ and the major fractions are from Southeast Asia
$(16 \%)$ and the tropical Pacific $(15 \%).$},
cin = {IEK-7},
ddc = {550},
cid = {I:(DE-Juel1)IEK-7-20101013},
pnm = {244 - Composition and dynamics of the upper troposphere and
middle atmosphere (POF3-244)},
pid = {G:(DE-HGF)POF3-244},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000467412800001},
doi = {10.5194/acp-19-6007-2019},
url = {https://juser.fz-juelich.de/record/862877},
}