A Multisensor Analysis of the Life Cycle of Bow Echo over Indian Region

Devajyoti Dutta,Diganta Kumar Sarma,Sanjay Sharma

doi:10.1155/2014/207064

Abstract

This study deals with the life cycle of bow echo events on October 24 and 26-27, 2006, from Doppler weather radar (DWR) observations supported by Radiosonde and National Centers for Environmental Prediction (NCEP). The cell bow echo (CBE) on October 24 evolved from two small isolated cells with radar reflectivity ≥40 dBZ. The vertical structure consists of one single mature cell with 20 dBZ echoes reaching up to 10 km while 40 dBZ echoes extended uniformly from ground to ∼5 km height. The radial velocity shows a high value >−15 m/s towards the radar at the upper height (about 6 to 11 km); the lower height is predominant with velocity away from the radar (about 5 to 15 m/s). The squall line bow echo on October 26 and 27 has its origin over ocean and moved towards the radar site and decayed thereafter. The radar reflectivity pattern for this squall line showed it to be a trailing stratiform type squall line with length of ∼200 km. The echo top height was more than 12 km in height. Strong inflow cases were observed from both radiosonde and radar.

Highlights

The life cycle of mesoscale convective systems (MCSs) can be studied with the help of on-board IR and microwave sensors as well as ground based Doppler weather radar (DWR) [1]
Life cycles of cell bow echo (CBE) and Squall Line Bow Echo (SLBE) are studied with the DWR observations
The kinematics of the squall line bow echoes are studied with the help of radial velocity from DWR

Summary

Introduction

The life cycle of mesoscale convective systems (MCSs) can be studied with the help of on-board IR and microwave sensors as well as ground based Doppler weather radar (DWR) [1]. The severe weather events are mostly associated with the organized MCSs such as bow echoes and squall lines. Klimowsky et al [14, 15] studied the early evolution of bow echoes from radar observations They observed three initial modes of formation of bow echoes: (i) weakly organized cells, (ii) squall line, and (iii) super cells. The present study deals with the study of the organized MCSs such as “Bow Echoes” with the help of ground based DWR and Radiosonde observations over the Indian region. In this study the evolution and life cycles of two different bow echo events on October 24 and 26-27, 2006, are considered

System Description and Data Used

Case Study

Results and Discussion

Conclusion