Studies on structure and formation/development Mechanisms of Mesoscale Convective Systems

- An address of our new project -

Masanori Yoshizaki
Meteorological Research Institute, Japan Meteorological Agency, Japan


A new project of ``Studies on structure and formation/development mechanisms of mesoscale convective systems'' supported by Japan Science and Technology Corporation (JST) - Core Research for Evolutional Science and Technology (CREST) started from October 1998. It continues until October 2003. We expect that this project stimulates research activity of mesoscale meteorology in Japan and makes breakthrough for new and further studies.
We opened a homepage (HP) of this project in order to communicate and give/take information. It will be frequently renewed when interesting news and reports are attained. We hope many people utilize this HP and get fruitful products through active communication and cooperation.
I am a principal researcher of this project. Mesoscale convective systems (MCSs) are my main concern. MCSs sometimes bring severe weathers such as gust wind, heavy precipitation, lightening and so on, and therefore the logo mark in the title was made as a combination of three legendary gods; lightening (left), rain (dragon, middle) and wind (right). Ancient Japanese people believed that such meteorological phenomena were brought by these gods. Now we want to see them more clearly and elucidate their works by this project. Hereafter I present outlines of objectives, research activity and observation plans under the project.

Objectives of this project:

MCSs have horizontal scales of 100km, consisting of convective and stratiform regions. Their horizontal form is various; line-shaped, hook-shaped, and so on. They last for a long time by self-enhancement and organization. MCSs play a key role on cycles of water and energy in the global circulation and also bring heavy precipitation, sometimes producing serious disasters. In Japan, MCSs occur with Baiu front, convergence bands/ small-scale cyclones over Japan Sea in winter, typhoons, and thunderstorms over central mountains in summer. They are an important part of multi-scale structures.
In this project, clarification of MCSs and multi-scale structures is aimed at. For these purposes, studies combined with field experiments, analyses, and numerical simulations are systematically performed about Baiu front around Kyushu and convergence bands/ small-scale cyclones over Japan Sea in winter. As field experiments, surface networks of Doppler radar, upper sounding, GPS, boundary-layer radar (BLR) and observation vessels, and mobile airplanes are combined. We want to elucidate inner structures of MCSs, their formation/development mechanisms, accompanying disturbances such as intermediate-scale disturbances and relationships between MCSs and environmental fields.

Processes of research:

In this project, our research is processed as follows; (1) purchase of meso-scale observation instruments and construction of ground-based observation system, (2) special observations of MCSs, (3) production of data base of special observation, (4) analytical studies, (5) numerical studies, and (6) comparative studies with other MCSs and summary. In particular, in (1) we purchased two BLRs, two surface meteorological systems and one microwave radiometer for measuring vertical profiles of temperature and moisture. We want to make a prototype of ground-based measuring system by combining these instruments. In (2), total observations by combining surface networks of Doppler radar, upper sounding, GPS and BLRs, and mobile airplanes are planed once every fiscal year. Further, in (5), real-time (but not operational) numerical simulations will be performed during special observation periods by using a non-hydrostatic numerical model (MRI-NHM). By utilizing these numerical results, mechanisms of self-enhancement and organizations of MCSs are studies.

Research plan of fiscal year: (Fiscal year starts in April in Japan.):

Note: The observation plans may be changed when cooperation with other observations is required.


Corresponding author address:
Masanori Yoshizaki
1-1 Nagamine,Tsukuba,Ibaraki 305-0052 JAPAN
Tel: +81-298-53-8631
Fax: +81-298-53-8649
E-mail: myoshiza@mri-jma.go.jp