1990 Fiscal Year Final Research Report Summary

The Study of Low-Level Wind Shear and Structure of Small Scale Turbulence Occurred in the Sea Breeze Penetration.

Research Project

Project/Area Number	01540344
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	気象・海洋・陸水学
Research Institution	Faculty of Science, Kochi University
Principal Investigator	CHIBA Osamu Faculty of Science, Associate Professor, 理学部, 助教授 (00036576)
Project Period (FY)	1989 – 1990
Keywords	Sea Breeze Front / Ultra-Sonic Anemometer-Thermometer / Doppler Sodar / Wind Shear / Sureace Layer / Eddy Motion / Frontal Width / Penetration Time of Sea Breeze
Research Abstract	The observation of the sea breeze has been carried out in the Atmospheric Boundary-Layer Observatory (ABO) of Kochi University during the period from 1986 to 1991. The two main measuring equipments ([1]Sonic Anemometer-Thermometer (SAT) and[2]Doppler sodar) were used to investigate the penetration time of sea breeze and the turbulent structure of the surface layer affected by the sea breeze pnetration. The empirical formulae of the penetration time obtained by both SAT and Sodar, after a harmonic analysis, indicate clear seasonal variation and strongly related to variation in sun rise time. Sea breeze front often occasion some of the strong wind shear at the surface, reflecting the large downdraft (before front penetration) and updraft (after front penetration). These flows also effect the turbulence quantities such as the scale of turbulence and the dissipation of turbulent kinetic energy.