Environment and Processes for Heavy Rainfall in the Early Morning over the Korean Peninsula during Episodes of Cloud Clusters Associated with Mesoscale Troughs

Shin, Uju; Lee, Tae Young; Park, Sang Hun

doi:10.2151/jmsj.2019-036

Cited by 11 publications

(14 citation statements)

References 24 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8b). Environmental conditions for CCMT-S have already been reported by Shin et al (2019). As regards CCMT-M, an MCS occurred over the Yellow Sea at about 2100 UTC 15 July and developed into a CC after 2300 UTC slowly moving northeastward.…”

Section: Ccmt Case Studymentioning

confidence: 68%

“…It is well known that transport of humid low-level air from the south or southwest by strong low-level wind is a key element for the occurrences of heavy rainfall over the Korean peninsula and southwestern Japan (e.g., Park et al 1983;Ogura et al 1985;Jeong et al 2016;Kato 2018;Shin et al 2019). Ninomiya and Yamazaki (1979) suggested that the generation of convective instability in the heavy rainfall area within the Baiu front was mainly due to the warm-moist advection in the lower layers.…”

Section: Introductionmentioning

confidence: 99%

“…Recent study by Shin et al (2019) showed the presence of elevated convective instability above a shallow convectively stable surface layer upstream of cloud clusters (CCs). The presence of elevated convective instability in the lower troposphere implies the possibility that convection initiation (CI) can occur at elevated levels.…”

Section: Introductionmentioning

confidence: 99%

“…Cloud clusters over the Korean peninsula and the Yellow Sea form mostly in an environment with a relatively weak baroclinicity along the northwestern edge of the western Pacific subtropical high (WPSH). The strong southwesterlies or LLJs along the northwestern edge of the WPSH play a critical role in CC formation (Shin et al 2019) and cause heavy rainfall over the Korean peninsula (e.g., Kim et al 1983;Hwang and Lee 1993;Chen et al 1999, etc.). Shin and Lee (2015) and Shin et al (2019) found that strong southwesterly bands (SWBs; regions wherein southwesterly wind speeds exceed 12.5 m s −1 ) develop along the northwestern edge of the WPSH as mesoscale depressions (i.e., MLs and MTs) appear near or along the edge.…”

Section: Introductionmentioning

confidence: 99%

“…The strong southwesterlies or LLJs along the northwestern edge of the WPSH play a critical role in CC formation (Shin et al 2019) and cause heavy rainfall over the Korean peninsula (e.g., Kim et al 1983;Hwang and Lee 1993;Chen et al 1999, etc.). Shin and Lee (2015) and Shin et al (2019) found that strong southwesterly bands (SWBs; regions wherein southwesterly wind speeds exceed 12.5 m s −1 ) develop along the northwestern edge of the WPSH as mesoscale depressions (i.e., MLs and MTs) appear near or along the edge. Further, they suggested that SWB caused CC development by bringing along a large amount of moisture over the southwestern Korean peninsula along with a zone of significant convergence over its northeastern terminus.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Atmospheric Structure for Convective Development in the Events of Cloud Clusters over the Korean Peninsula

Lee

Shin

Park

2020

Asia-Pacific J Atmos Sci

Self Cite

View full text Add to dashboard Cite

This study examines atmospheric structures causing convective development in the events of cloud cluster (CC) over the Korean peninsula using the analysis and forecast data of National Centers for Environmental Prediction (NCEP) climate forecast system reanalysis (CFSR) and observation data. Two CC types-CCs associated with meso-α-scale lows (CCMLs) and mesoscale troughs (CCMTs)-were investigated. The common atmospheric structure for convective development in CC events is comprised of i) a strong southwesterly band (SWB; a region with southwesterly wind speeds >12.5 m s −1) in the lower troposphere upstream of CCs with a mesoscale convergence zone in its exit area, ii) a layer of high-θ e air in the lower troposphere near the surface extending from the southwest to SWB exit, iii) elevated height of maximum θ e in the lower troposphere near and over the convergence zone, above which a convectively unstable layer exists. Generality of the above-described structure has been demonstrated via examination of composite fields. SWB plays a major role in producing the structure for convective development in CC events over the Korean peninsula mainly through i) advection of high-θ e air from the southwest, and ii) significant horizontal convergence in the exit area, which can facilitate convection initiation. The two types of CC show notable differences in atmospheric structure across the boundary between high-θ e air from the southwest and low-θ e air in the northeast and in the mode of high-θ e air transport to the region of convective development. The boundary is generally tilted northeastward with height for CCML cases, whereas it is nearly vertical for the majority of CCMT cases. This study indicates that, despite the abovementioned differences, convective developments in both CC types can be considered as elevated convection that occurs as air parcels in an elevated layer of convective instability are lifted by upward motion in the convergence zone. For both types of CC, differential θ e advection plays the key role for the occurrence of elevated layer of convective instability. And θ e front in CCML events indicates the presence of elevated convective instability above it and the possibility of elevated convection provided that a lifting mechanism is available.

show abstract

Section: Ccmt Case Studymentioning

confidence: 68%