ACPD

Atmospheric Chemistry and Physics Discussions

ACPD

Atmos. Chem. Phys. Discuss.

1680-7375

Göttingen, Germany

10.5194/acp-2019-743

Influence of Asian Summer Monsoon Anticyclone on the Trace gases and Aerosols over Indian region

Basha

Ghouse

https://orcid.org/0000-0002-1127-7000

¹ Ratnam

M. Venkat

¹ Kishore

Pangaluru

https://orcid.org/0000-0003-0076-5452

² Ravindrababu

https://orcid.org/0000-0002-1313-8864

³ Velicogna

Isabella

https://orcid.org/0000-0002-9020-1898

National Atmospheric Research Laboratory, Department of Space, Gadanki-517112, India

Department of Earth System Science, University of California, Irvine, CA, 92697, USA

Center for Space and Remote Sensing Research, National Central University, No. 300, Jhongda Rd., Jhongli Dist., Taoyuan City 32001, Taiwan

02 12 2019

2019 1 33

2019

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://acp.copernicus.org/preprints/acp-2019-743/

The full text article is available as a PDF file from https://acp.copernicus.org/preprints/acp-2019-743/acp-2019-743.pdf

The Asian Summer Monsoon Anticyclone (ASMA) persisting during monsoon season in the upper troposphere and lower stratosphere (UTLS) region play an important role in confining the trace gases and aerosols for a longer period thus affects regional and global climate. Our understanding on these trace gases and aerosols variability in the ASMA is limited. In this study, the effect of the ASMA on the trace gases (Water Vapour (WV), Ozone (O3), Carbon Monoxide (CO)) and aerosols (Attenuated Scattering Ratio (ASR)) obtained from long-term (2006–2016) satellite measurements is investigated. Since the ASMA is present in the UTLS region, its influence on the tropopause characteristics is also explored. Higher tropopause altitude, WV, CO and ASR confining to the ASMA region is observed, whereas tropopause temperatures and O3 are found low. There exists large inter-annual variation in the ASMA and hence its effect on these trace gases and aerosols are also seen clearly. A significant relationship is also observed between the phases of Quasi-Biannual Oscillation (QBO) and El Niño Southern Oscillation (ENSO) on the trace gases and ASR, including the tropopause when measurements in the ASMA region are subject to multivariate regression analysis. Further, the influence of the Indian summer monsoon (ISM) activity on the ASMA trace gases and aerosols is studied with respect to active and break spells of monsoon, strong and weak monsoon years, strong La Niña, El Niño years. Results show a significant increase in WV, CO and decrease in O3 during the active phase of the ISM, strong monsoon years and strong La Niña years in the ASMA. Enhancement in the ASR values during the strong monsoon years and strong La Niña years is observed. Thus, it is prudent to conclude that the dynamics of the ASMA play an important role in the confinement of several trace gases and aerosols and suggested to consider the activity of summer monsoon while dealing with them at sub-seasonal scales.