Local winds over the Lake Biwa basin

局地风是由地形引起的中尺度风系。琵琶湖盆地可以产生多种当地风，该盆地位于本州岛最狭窄的地区，包含湖泊、平原、山脉，本文指出，白天，湖面和平原上的湖风与山区上的谷风结合成从湖面向盆地边缘的辐散气流，而与陆地和平原结合的辐合气流，则是从盆地边缘向盆地边缘辐散气流的一种。晚上的山风是反方向的。然而，通过详细考察风的日变化，我们注意到在琵琶湖盆地的北方，傍晚时开始吹偏北风或偏东风。本文试图阐明傍晚时发展的偏北风和偏东风的特征和来源。为此目的，我们于1985年和1986年在湖东北海岸的Onoe进行了地面风的实地观测。在 关于我们 此外，我们还观测了1985年8月2-4日在小野江的风和温度的垂直分布。所得结果概括如下：1）在弱的一般风的影响下，无论是北偏风（NW-N）还是东偏风（E-SE），傍晚（约16 - 21 LST）都伴随着湖风，例如，在Ibukiyama气象站（海拔1, 377 m）18 LST时的风速低于10 m/s。无论总风向如何，北风都在发展。偏东风与较强的东南风总风同时发展，如Ibukiyama气象站18 L13 EA：ST风速大于5 m/s。2）推断偏北风是从若狭湾地区进入琵琶湖流域的海风。其平均持续时间、平均风速和平均水平尺度为5小时（16 - 21 LST），3.5 m/s。（3）推断东风为地峡背风侧强风“大士风”，是地峡修正的东南风一般风。1985年8月2-4日在小野江的大风持续时间、风速和垂直尺度为14小时（17 - 7 LST），7-11 m/s。300-500 m。少

Local winds are terrain-induced mesoscale wind systems. Many kinds of local winds can develop in the Lake Biwa Basin, which is located in the narrowest part of Honshu Island and contains a lake, plains, mountains, and isthmuses.It has been pointed out that a lake breeze over the lake and plains and a valley wind over mountain areas are combined into divergent flow from the lake toward the edge of the basin in the daytime and that convergent flow combined with a land and a mountain wind develops in the opposite direction at night. However, examining diurnal variation in wind in detail, we notice that either a northerly or an easterly wind begins to blow toward evening in the northern part of the Lake Biwa Basin.This paper intends to clarify the features and orgin of both the northerly wind and the easterly wind that develop toward evening. For this purpose, we carried out field observations of a surface wind at Onoe on the northeast shore of the lake in su13EA\ : mmer 1985 and 1986. In … More addition, we observed vertical distributions of wind and temperature at Onoe on 2-4 August 1985.The results obtained are summarized as follows :1) Either a northerly wind (NW-N) or an easterly wind (E-SE) follows a lake breeze toward evening (about 16 to 21 LST) under the influence of a weak general wind ; for instance, wind speed at 18 LST at Ibukiyama Weather Station (1,377m above the sea13EA\ : level) is lower than about 10 m/s. The northerly wind develops regardless of the general wind direction. The easterly wind, however, develops frequently together with a relatively strong southeasterly general wind ; for instance, wind speed at 18 L13EA\ : ST at Ibukiyama Weather Station is greater than about 5 m/s.2) It is deduced that the northerly wind is a sea breeze entering from Wakasa Bay area into Lake Biwa Basin. Its mean duration time, mean wind speed, and mean horizontal scale are 5 hours (16 to 21 LST), 3.5 m/s. and 63 km, respectively.3) It is deduced that the easterly wind is "Dashikaze", a strong wind on the lee side of an isthmus, which is a southeasterly general wind modified by the isthmus. Duration time, wind speed, and vertical scale of Dashikaze at Onoe on 2-4 August 198513EA\ : are 14 hours (17 to 7 LST), 7-11 m/s. and 300-500 m, respectively. Less