Synoptic disturbances over the equatorial South China Sea and western Maritime Continent during boreal winter
MetadataShow full item record
During boreal winter, the Maritime Continent is a region of deep cumulus convection and heavy precipitation systems that play a major role in several global- and regional-scale processes. Over the western part of this region, the synoptic-scale Borneo vortex and northeast cold surge and the intraseasonal Madden Julian Oscillation (MJO) contribute to the variability in deep convection. This work studies the impact on deep convection due to interactions among these three different motion systems. Furthermore, the role of the unique topography of the region is examined with respect to the variability in the synoptic-scale cold surge and Borneo vortex. On the synoptic scale, interaction of northeast winds with local topography and dynamic response to the change in latitude contribute to turning of the winds and localized patterns of deep convection. In days without a Borneo vortex, deep convection tends to be suppressed over the South China Sea and Borneo and enhanced downstream over the landmasses on the western and southern peripheries of the equatorial South China Sea. The pattern is reversed in days with a vortex. The presence of a cold surge enhances this contrast. The surge also interacts with the Borneo vortex, in that the vortex is strengthened and the vortex center shifts from over the South China Sea to be located over the western coast of Borneo. The frequency of cold surges and vortex days is reduced during periods when the MJO is present. Composites of large-scale circulation and outgoing longwave radiation are used to show that often the MJO-related circulation patterns oppose the synoptic-scale cold surge and vortex circulations. Thus, a primary impact of the MJO is to inhibit weak 2 cold surge events, which then produces a secondary impact on the Borneo vortex via interactions between the cold surge winds and the vortex.
Mon. Wea. Rev., 133, 489-503. (Manuscript)
Showing items related by title, author, creator and subject.
Observations of the temporal variability in aerosol properties and their relationships to meteorology in the summer monsoonal South China Sea/East Sea: the scale-dependent role of monsoonal flows, the Madden-Julian Oscillation, tropical cyclones, squall lines and cold pools Reid, J.S.; Lagrosas, N.D.; Jonsson, H.H.; Reid, E.A.; Sessions, W.R.; Simpas, J.B.; Uy, S.N.; Boyd, T.J.; Atwood, S.A.; Blake, D.R.; Campbell, J.R.; Cliff, S.S.; Holben, B.N.; Holz, R.E.; Hyer, E.J.; Lynch, P.; Meinardi, S.; Posselt, D.J.; Richardson, K.A.; Salinas, S.V.; Smirnov, A.; Wang, Q.; Yu, L.; Zhang, J. (2015);In a joint NRL/Manila Observatory mission, as part of the Seven SouthEast Asian Studies program (7- SEAS), a 2-week, late September 2011 research cruise in the northern Palawan archipelago was undertaken to observe the ...
Combining New Satellite Tools and Models to Examine Role of Mesoscale Interactions in Formation and Intensification of Tropical Cyclones Simpson, Joanne; Pierce, H.; Ritchie, L.; Liu, T.; Brueske, K.; Velden, C.; Halverson, J.; Einaudi, Franco (Technical Monitor) (2001-01);The objective of this research is to start filling the mesoscale gap to improve understanding and probability forecasts of formation and intensity variations of tropical cyclones. Sampling by aircraft equipped to measure ...
McNitt, James A. (1984-12);The Marginal Ice Zone Experiment (MIZEX-83) conducted in the Arctic during the summer of 1983 is summarized and the mesoscale features and atmospheric refraction conditions described. The three case studies examined are: ...