TY  - JOUR
AU  - Vogel, Bärbel
AU  - Günther, G.
AU  - Müller, Rolf
AU  - Grooss, Jens-Uwe
AU  - Riese, M.
TI  - Impact of different Asian source regions on the composition of the Asian monsoon anticyclone and on the extratropical lowermost stratosphere
JO  - Atmospheric chemistry and physics / Discussions
VL  - 15
IS  - 7
SN  - 1680-7375
CY  - Katlenburg-Lindau
PB  - EGU
M1  - FZJ-2015-06457
SP  - 9941 - 9995
PY  - 2015
AB  - The impact of different boundary layer source regions in Asia on the chemical composition of the Asian monsoon anticyclone, considering its intraseasonal variability in 2012, is analysed by CLaMS simulations using artificial emission tracers. Our simulations show that the Asian monsoon anticyclone is highly variable in location and shape and oscillates between 2 states: first a symmetric anticyclone and second, an asymmetric anticyclone either elongated or split in two smaller anticyclones. A maximum in the distribution of air originating from Indian/Chinese boundary layer sources is usually found in the core of the symmetric anticyclone, in contrast the asymmetric state is characterised by a double peak structure in the horizontal distribution of air originating from India and China. The simulated horizontal distribution of artificial emission tracers for India/China is in agreement with patterns found in satellite measurements of O3 and CO by the Aura Microwave Limb Sounder (MLS). The contribution of different boundary source regions to the Asian monsoon anticyclone strongly depends on its intraseasonal variability and is therefore more complex than hitherto believed, but in general the highest contributions are from North India and Southeast Asia at 380 K. In the early (June to mid-July) and late (mid-August to October) period of the monsoon 2012, contributions of emissions from Southeast Asia are highest and in the intervening period (≈ mid-July to mid-August) emissions from North India have the largest impact. Further, our simulations confirm that the thermal tropopause above the anticyclone constitutes a vertical transport barrier. Enhanced contributions of emission tracers for Asia are found at the northern flank of the Asian monsoon anticyclone between double tropopauses indicating an isentropic transport from the anticyclone into the lowermost stratosphere.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.5194/acpd-15-9941-2015
UR  - https://juser.fz-juelich.de/record/256583
ER  -