Study of Stratospheric Sudden Warming (SSW) over the tropical and subtropical regions of India using Rayleigh lidar

ABSTRACT

The Stratospheric Sudden Warming (SSW) is one of the most spectacular phenomena in the atmosphere and has impacts on the Earth’s lower, middle, and upper atmospheres. In this study, two major SSW episodes associated with vortex displacement and vortex splitting that occurred in the years 1998 and 1999, respectively, are investigated for the first time over Mt. Abu using lidar observations. Analyses show that ground-based lidar and satellite observations from the Halogen occultation experiment (HALOE) on board the upper atmospheric research satellite (UARS) can capture the effect of SSW events. Lidar measurements are able to capture SSW warming and its decay very accurately. The impact of SSW is further investigated in the European Centre for Medium-Range Weather Forecasts (ECMWF) Interim-reanalysed potential vorticity. Moreover, a detailed study has been presented to understand the latitudinal variation of SSW warming and the associated mesospheric cooling over the Indian region. The results showed that warming is higher over the northern Indian region (35° N, 77° E) compared with the southern Indian region (5° N, 77° E).

Highlights

• Two major SSW episodes are investigated using lidar observations.

• HALOE on board UARS are able to capture the effect of SSW events.

• Investigate the latitudinal variation of SSW warming and associated mesospheric cooling.

Acknowledgements

The authors are thankful to all the lidar group members for up-keeping the instruments and help in lidar observation at PRL and Gadanki. The authors are grateful to HALOE on board UARS, SABER on board TIMED, and CIRA-86 and MSISE-90 team members for providing valuable temperature data. The global model analysis available from ECMWF Interim is acknowledged with sincere thanks (http://apps.ecmwf.int/). This work was supported by the Department of Space, Government of India. Authors are thankful to Miss Preeti, summer intern at PRL for data analysis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Department of Space, Government of India.