Study of the spatial structure of urban heat island in regional central cities by laser radar

最近，一串积雨链(被称为kanpachi gumo)频繁出现在东京的kanpachi街上空。通过对1989年云链温度和风分布的个例分析，得出如下结论：1)当日本群岛被太平洋高压覆盖时，云链出现；2)来自相模湾的西南海风和来自东京湾的西南海风在白天形成了一个沿日本关帕奇街的局地辐合区。因此，坎帕奇街周围出现了上升的气流。3)坎帕奇街周围在白天形成了一个显著的热岛。1992年夏季，利用低空无线电探测、试飞气球等手段对坎帕奇街上空的云链进行了观测。主要结果如下：4)云顶高度约为15000 m，比前人研究高出约500m。5)白天，来自东京湾和相模湾的海风在坎帕奇街上空辐合。6)下午，坎帕奇街沿线出现高温区。我们成功地获得了气溶胶的垂直分布，以显示城市热岛的结构。

Recently, a chain of cumulus (called Kanpachi Gumo) frequently appears over the Kanpachi Street in Tokyo. From the case studies of the temperature and wind distributions in relation to the cloud chain in 1989, it is concluded as follows:1) The cloud chain appeared, when Japan Islands were covered with the Pacific high.2) The south-southewest sea breeze from Sagami Bay and the south-southeast sea breeze from Tokyo Bay formed a local convergence area along the Kanpachi Street during the daytime. Consequently, an ascending air current occurred around Kanpachi Street.3) A remarkable heat island was formed around Kanpachi Street during the day time. As a result, the convection was reinforced by the heat island circulation.The observation of the cloud chain over the Kanpachi Street was carried out by using low-level radio sound, pilot balloon, etc. during the summer in 1992. The main results are summarized as follows:4) The height of the cloud top was about 15000 m, and was about 500 m higher than that of the previous study.5) In the daytime, the convergence are of sea breezes from the Tokyo Bay and from the Sagami Bay existed over the Kanpachi Street.6) In the afternoon, high temperature zone was observed along the Kanpachi Street.In the present study, a portable laser radar for meteorological measurements in atmospheric boundary layer and troposphere has been developed. We succeeded to obrained vertical distribution of aerosols to show the structure of the urban heat island.