TY - JOUR
T1 - High tropospheric ozone in Lhasa within the Asian summer monsoon anticyclone in 2013
T2 - Influence of convective transport and stratospheric intrusions
AU - Li, Dan
AU - Vogel, Barbel
AU - Müller, Rolf
AU - Bian, Jianchun
AU - Günther, Gebhard
AU - Li, Qian
AU - Zhang, Jinqiang
AU - Bai, Zhixuan
AU - Vömel, Holger
AU - Riese, Martin
N1 - Publisher Copyright:
© 2018. This work is distributed under the Creative Commons Attribution 4.0 License.
PY - 2018/12/18
Y1 - 2018/12/18
N2 - Balloon-borne measurements of ozone in Lhasa (29.66ĝ N, 91.14ĝ E; 3650 m above sea level) in August 2013 are investigated using backward trajectory calculations performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS). Measurements show three time periods characterized by high ozone mixing ratios (OMRs) in the troposphere on 8, 11, and 18-20 August 2013 during the Asian summer monsoon (ASM) season. Here, we verified two different sources for the enhanced ozone values in the troposphere. First, transport of polluted air from the boundary layer, and second downward transport from the stratosphere by stratospheric intrusions. Air pollution from South Asia through convective and long-range transport plays a key role in enhancing middle tropospheric OMRs up to 90 % on 8 August and up to 125 % on 11 August 2013 compared to monthly mean ozone of August 2013. Stratospheric air intruded from the northern high-latitudes to the southeastern flank of the ASM anticyclone to the troposphere and is identified as the source of enhanced ozone according to backward trajectory calculation and satellite measurements by the Ozone Monitoring Instrument (OMI) and the Atmospheric Infrared Sounder (AIRS). Air parcels with high ozone moved from the high-latitude lower stratosphere to the middle and upper troposphere. These air parcels are then transported to Lhasa over long distances and enhanced upper and middle tropospheric ozone over Lhasa during 18-20 August 2013. Our findings demonstrate that the strong variability of ozone within the ASM anticyclone in the free troposphere is caused by transport from very different regions of the atmosphere.
AB - Balloon-borne measurements of ozone in Lhasa (29.66ĝ N, 91.14ĝ E; 3650 m above sea level) in August 2013 are investigated using backward trajectory calculations performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS). Measurements show three time periods characterized by high ozone mixing ratios (OMRs) in the troposphere on 8, 11, and 18-20 August 2013 during the Asian summer monsoon (ASM) season. Here, we verified two different sources for the enhanced ozone values in the troposphere. First, transport of polluted air from the boundary layer, and second downward transport from the stratosphere by stratospheric intrusions. Air pollution from South Asia through convective and long-range transport plays a key role in enhancing middle tropospheric OMRs up to 90 % on 8 August and up to 125 % on 11 August 2013 compared to monthly mean ozone of August 2013. Stratospheric air intruded from the northern high-latitudes to the southeastern flank of the ASM anticyclone to the troposphere and is identified as the source of enhanced ozone according to backward trajectory calculation and satellite measurements by the Ozone Monitoring Instrument (OMI) and the Atmospheric Infrared Sounder (AIRS). Air parcels with high ozone moved from the high-latitude lower stratosphere to the middle and upper troposphere. These air parcels are then transported to Lhasa over long distances and enhanced upper and middle tropospheric ozone over Lhasa during 18-20 August 2013. Our findings demonstrate that the strong variability of ozone within the ASM anticyclone in the free troposphere is caused by transport from very different regions of the atmosphere.
UR - https://www.scopus.com/pages/publications/85058862596
U2 - 10.5194/acp-18-17979-2018
DO - 10.5194/acp-18-17979-2018
M3 - Article
AN - SCOPUS:85058862596
SN - 1680-7316
VL - 18
SP - 17979
EP - 17994
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 24
ER -