[A-AS10] General Meteorology

[AAS10-08] Cold pool and horizontal vortex tube of line-shaped convective systems contributing to elucidation of airflow structure

★Invited Papers

*Yoshiyuki Kawatani^1,2, Kosei Yamaguchi², Eiichi Nakakita², Shinsuke Satoh¹, Hiroshi Hanado¹, Seiji Kawamura¹ (1.National Institute of Infomation and Communications Technology, 2.Disaster Prevention Reseach Institute, Kyoto University)

Keywords:line-shaped convective systems, cold pool, horizontal vortex tube

These days, line-shaped convective systems have frequently occurred and brought some disasters such as landslide and flood. They are self-organized with back building structure, and it maintains heavy rainfall at same place. Mechanism of line-shaped convective systems is not still clarified, so prediction is difficult. To clarify mechanism of the generation and maintenance of line-shaped convective systems in detail, we analyzed airflow structure whose spatial scale is same as line-shaped convective system, with reproductive experiment with numerical model. As a result of reproductive experiment, line-shaped convective system was generated. We focused on convergence by topography, cold pool and horizontal vortex tube. (1) To understand the reason why rainfall area was shaped linearly, updraft and horizontal convergence were examined. Topography formed line-shaped updraft and convergence area. (2) Cold pool generated by precede rainfall area brought strong temperature gradient and convergence line as cause of strong self-organization. (3) From (1) and (2), we found out that two convergence lines are important. However, convergence line by topography was maintained far from topography in maintenance phase. We focused on horizontal vortex tube along line-shaped updraft area. It was stretched and maintained, so convergence line was also still maintained. In the future, we will conduct some ideal experiments under simpler conditions to generalize the airflow structure in Kansai district.