Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/100027
Title: Borneo vortex and mesoscale convective rainfall
Authors: Koseki, Shunya
Koh, Tieh Yong
Teo, Chee Kiat
Keywords: DRNTU::Science::Physics::Meteorology and climatology
Issue Date: 2014
Source: Koseki, S., Koh, T. Y., & Teo, C. K. (2014). Borneo vortex and mesoscale convective rainfall. Atmospheric Chemistry and Physics, 14(9), 4539-4562.
Series/Report no.: Atmospheric chemistry and physics
Abstract: We have investigated how the Borneo vortex develops over the equatorial South China Sea under cold surge conditions in December during the Asian winter monsoon. Composite analysis using reanalysis and satellite data sets has revealed that absolute vorticity and water vapour are transported by strong cold surges from upstream of the South China Sea to around the Equator. Rainfall is correspondingly enhanced over the equatorial South China Sea. A semi-idealized experiment reproduced the Borneo vortex over the equatorial South China Sea during a "perpetual" cold surge. The Borneo vortex is manifested as a meso-α cyclone with a comma-shaped rainband in the northeast sector of the cyclone. Vorticity budget analysis showed that the growth/maintenance of the meso-α cyclone was achieved mainly by the vortex stretching. This vortex stretching is due to the upward motion forced by the latent heat release around the cyclone centre. The comma-shaped rainband consists of clusters of meso-β-scale rainfall cells. The intense rainfall in the comma head (comma tail) is generated by the confluence of the warmer and wetter cyclonic easterly flow (cyclonic southeasterly flow) and the cooler and drier northeasterly surge in the northwestern (northeastern) sector of the cyclone. Intense upward motion and heavy rainfall resulted due to the low-level convergence and the favourable thermodynamic profile at the confluence zone. In particular, the convergence in the northwestern sector is responsible for maintenance of the meso-α cyclone system. At both meso-α and meso-β scales, the convergence is ultimately caused by the deviatoric strain in the confluence wind pattern but is significantly self-enhanced by the nonlinear dynamics.
URI: https://hdl.handle.net/10356/100027
http://hdl.handle.net/10220/19656
ISSN: 1680-7324
DOI: 10.5194/acp-14-4539-2014
Rights: © Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:EOS Journal Articles
SPMS Journal Articles
TL Journal Articles

Files in This Item:
File Description SizeFormat 
Borneo vortex and mesoscale convective rainfall.pdf8.68 MBAdobe PDFThumbnail
View/Open

SCOPUSTM   
Citations

18
checked on Sep 6, 2020

WEB OF SCIENCETM
Citations

17
checked on Sep 22, 2020

Page view(s)

625
checked on Sep 25, 2020

Download(s)

802
checked on Sep 25, 2020

Google ScholarTM

Check

Altmetric


Plumx

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.