TITLE

Synoptic Disturbances over the Equatorial South China Sea and Western Maritime Continent during Boreal Winter

AUTHOR(S)
Chang, C.-P.; Harr, P. A.; Chen, H.-J.
PUB. DATE
March 2005
SOURCE
Monthly Weather Review;Mar2005, Vol. 133 Issue 3, p489
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
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, the 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, the interaction of northeast winds with local topography and the dynamic response to the change in latitude contribute to the 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 cold-surge events, which then produces a secondary impact on the Borneo vortex via interactions between the cold-surge winds and the vortex.
ACCESSION #
16519921

 

Related Articles

  • Upshear and downshear evolution of cloud structure and spectral properties. Vaillancourt, P. A.; Yau, M.K.; Grabowski, W. W. // Journal of the Atmospheric Sciences;5/1/97, Vol. 54 Issue 9, p1203 

    Examines the upshear and downshear evolution of cloud structure and spectral properties by performing two-dimensional simulations of a small nonprecipitating cumulus cloud in the presence of wind shear. Soundings and series of time-lapse pictures of the development of cumulus clouds;...

  • Potential Vorticity Diagnostics of a Mei-Yu Front Case. George Tai-Jen Chen, S.; Chung-Chieh Wang, S.; Stepano Chih-Shin Liu, S. // Monthly Weather Review;Nov2003, Vol. 131 Issue 11, p2680 

    The present study selects the mei-yu frontal case of 12–13 June 1990 over southeastern China, and performs potential vorticity (PV) diagnostic analysis to discuss the mechanism responsible for the intensification and maintenance of frontal vorticity. The mei-yu front had typical...

  • Analysis of Humidity Halos around Trade Wind Cumulus Clouds. Lu, Miao-Ling; Wang, Jian; Freedman, Andrew; Jonsson, Haflidi H.; Flagan, Richard C.; McClatchey, Robert A.; Seinfeld, John H. // Journal of the Atmospheric Sciences;4/15/2003, Vol. 60 Issue 8, p1041 

    Regions of enhanced humidity in the vicinity of cumulus clouds, so-called cloud halos, reflect features of cloud evolution, exert radiative effects, and may serve as a locus for new particle formation. Reported here are the results of an aircraft sampling campaign carried out near Oahu, Hawaii,...

  • Humidity Halos Surrounding Small Cumulus Clouds in a Tropical Environment. Laird, Neil F. // Journal of the Atmospheric Sciences;9/1/2005, Vol. 62 Issue 9, p3420 

    A large dataset of aircraft cloud traverses from the Small Cumulus Microphysics Study (SCMS) was used to add to the existing knowledge of humidity halo characteristics for small cumulus clouds in a tropical environment. The findings from this investigation show a larger frequency of observed...

  • DAYS WITH RECOGNISABLE WIND PATTERNS. Watts, Alan // Instant Wind Forecasting;2005, p76 

    The article presents the characteristics of a day with recognizable wind patterns. It discusses fair weather with cumulus clouds, big cumulus-cumulonimbus and showers, warm days with thunder, and increasing high cloud and backing winds. Zones to seaward and landward of main coastline are also...

  • Regional Climate Model Simulations of U.S. Precipitation and Surface Air Temperature during 1982–2002: Interannual Variation. Jinhong Zhu; Xin-Zhong Liang // Journal of Climate;Jan2007, Vol. 20 Issue 2, p218 

    The fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5)-based regional climate model (CMM5) capability in simulating the interannual variations of U.S. precipitation and surface air temperature during 1982–2002 is evaluated with a continuous baseline...

  • Evidence for Tilted Toroidal Circulations in Cumulus. Damiani, Rick; Vali, Gabor // Journal of the Atmospheric Sciences;Jun2007, Vol. 64 Issue 6, p2045 

    Intense vortical circulations, often organized in counterrotating vortex pairs, were detected in midcontinental cumulus congestus over southeast Wyoming in July 2003. The sampled clouds developed in dry environments and at cold temperatures, and were a few kilometers in depth and width....

  • A novel technique for extracting clouds base height using ground based imaging. Hirsch, E.; Agassi, E.; Koren, I. // Atmospheric Measurement Techniques Discussions;2010, Vol. 3 Issue 5, p4231 

    The article discusses the novel technique for extracting clouds base height which uses a thermal imaging from the ground combined with wind profile data. In here, the method used is being analyzed such as its foundation which is the calculation of the angular velocity of the clouds. It reveals...

  • Simulation of monsoon depressions using MM5: sensitivity to cumulus parameterization schemes. Ratnam, J. Venkata; Cox, E. A. // Meteorology & Atmospheric Physics;Jun2006, Vol. 93 Issue 1/2, p53 

    The sensitivity of the simulation of the monsoon depressions to the cumulus parameterization schemes used in a numerical model is studied using the Pennsylvania State University – National Center for Atmospheric Research (PSU-NCAR) model MM5 version 3.6.2. Three different cases of monsoon...

Share

Read the Article

Courtesy of NEW JERSEY STATE LIBRARY

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics