毫米波雷达在小尺度云雾系统监测中的应用

运用毫米波雷达结合地面观测对2017年4月15-16日发生在宁波北部海域的大范围大雾天气过程进行了分析。结果表明:毫米波雷达可以实现对10 km左右的液态水系统、千米左右游离液态水团和更小尺度的局地短时液态水团等进行有效监测。10 km尺度的液态水系统过境使站点的能见度呈现深V型变化;未有液态水系统过境的站点,在靠近液态水系统时也会出现能见度变化。千米尺度的游离液态水团对能见度也有很强的影响,是造成无液态水系统过境时能见度急剧变化的主要原因之一。更小尺度的局地短时液态水团的形成与局地其他因素关系紧密,不能单以雷达反射率来进行分析。能见度的变化主要受毫米波雷达反射率相关因素和气象要素两者影响,约各占40%左右,毫米波雷达的应用将未确定因素导致的能见度变化次数降低到了20%以下。

Application of millimeter wave radar in small scale weather system

By using millimeter wave radar combined with ground observation station, the large-scale fog weather process in the northern sea area of Ningbo from the night of 15 to the morning of 16, April 2017 was analyzed. Results show that the millimeter wave radar can effectively monitor the liquid water system of about 10 km, free liquid water mass of about km and local short-term liquid water mass of smaller scale.The 10 km scale liquid water system transit makes the visibility of the station show a deep V-shaped change. The visibility of the station that is not transited by the liquid water system will also change when it is close to the liquid water system. Kilometer scale free liquid water mass also has a strong impact on visibility, which is one of the main reasons for the sharp change of visibility when there is no liquid water system. The formation of smaller scale local short-time liquid water mass is closely related to other local factors, so it cannot be analyzed by radar reflectivity alone. The change of visibility is mainly affected by both millimeter wave radar reflectivity related factors and meteorological factors, accounting for about 40% respectively. The application of millimeter wave radar reduces the number of visibility changes caused by uncertain factors to less than 20%.