1997 Fiscal Year Final Research Report Summary
Study of the Evolution Process of Middle-Level Stratiform Clouds
| Project/Area Number |
08640542
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Akita University |
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Principal Investigator |
KAJIKAWA Masahiro Akita University, Faculty of Education, Professor, 教育学部, 教授 (20042319)
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| Co-Investigator(Kenkyū-buntansha) |
ASUMA Yoshio Hokkaido University, Graduate School of Science, Lecturer, 大学院・理学研究科, 講師 (10183732)
HAYASHI Yoshio Akita University, Faculty of Education, Assistant Professor, 教育学部, 助教授 (90211490)
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| Project Period (FY) |
1996 – 1997
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| Keywords | stratiform cloud / glaciation / altostratus / middle-level cloud / radar-echo / liquid-water content / altocumulus / nimbostratus |
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| Research Abstract |
The evolution of middle-level stratiform clouds associated with various synoptic conditions were observed in summer and autumn of 1996, by means of a microwave radiometer and a vertical pointing X-band doppler radar. Glaciation and precipitation formation in middle-level clouds, in particular altostratus (As), were studied using the data of vertically integrated liquid-water content (LWP) by the microwave radiometer together with radar-echo intensity and the photographs of clouds. The following main results were obtained :
1) In the evolution from As to nimbostratus (Ns), LWP is more than 0.014cm with the radar-echo of As. When raindrops reach to ground surface, LWP is over 0.05cm. On the other hand, LWP is about 0.012cm when the precipitation is drizzle.
2) In the case of As associated with stratocumurus (Sc) of lower level, when raindrops reach to ground surface, LWP over 0.05cm with the radar-echoof lower level.
3) When As is accompained by convective cells, radar-echo onset in its lower part.
4) In the evolution from Sc to Ns, LWP is more than 0.01cm with the radar-echo in its lower part and drizzle reachs to ground level. When As or Ac overlaps in upper level of Sc, LWP is over 0.02cm.
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