Missed Fog?
Missed Fog?
复制标题
错过了雾吗？
DOI：
--
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发表时间：
2019
影响因子：
4.3
通讯作者：
B. V. D. van de Wiel
中科院分区：
文献类型：
--
作者：
Jonathan G. Izett;B. Schilperoort;M. Coenders;P. Baas;F. Bosveld;B. V. D. van de Wiel
传统的气象变量原位观测仅限于地表附近的有限高度，最低观测高度通常为1 m左右。这可能会导致错过观测的浅雾，和较厚的雾层的初始生长阶段。与此同时，数值试验表明，在近地层中需要有高的垂直网格分辨率，以准确地模拟雾的发生;这就需要相应的高分辨率观测数据进行验证。2017年11月，在荷兰的Cabauw大气研究实验场（塞萨尔）进行了为期两周的实地活动。其目的是观察浅雾层的增长情况，并评估在雾事件期间在地面附近获得非常高分辨率观测的可能性。温度和相对湿度测量厘米分辨率在最低的7米使用分布式温度传感。此外，一种新的方法，估计能见度在最低的2.5米，使用相机和扩展光源。这些观测得到了现场现有传统传感器的补充，包括沿着200米高的塔的传感器。提高分辨率的观测和他们的传统同行之间的比较表明，误差很小，给人的信心，在技术的可靠性。观测分辨率的提高，随后允许详细调查雾的生长和演变。这包括在最低的米（高达5 K）和相应的（超）饱和区域的雾形成的大逆温的观察。在两周的观测期间，在2.0 m的常规传感器高度上观测到两次雾。另外两个低能见度事件，观察到在最低的0-0.5米使用相机为基础的观测，但错过了传统的传感器。照相机观测还显示了浅辐射雾的增长，早在2米的常规高度观测到它之前的两个小时，就在最低的0.5米处形成了。
Conventional in situ observations of meteorological variables are restricted to a limited number of levels near the surface, with the lowest observation often made around 1-m height. This can result in missed observations of both shallow fog, and the initial growth stage of thicker fog layers. At the same time, numerical experiments have demonstrated the need for high vertical grid resolution in the near-surface layer to accurately simulate the onset of fog; this requires correspondingly high-resolution observational data for validation. A two-week field campaign was conducted in November 2017 at the Cabauw Experimental Site for Atmospheric Research (CESAR) in the Netherlands. The aim was to observe the growth of shallow fog layers and assess the possibility of obtaining very high-resolution observations near the surface during fog events. Temperature and relative humidity were measured at centimetre resolution in the lowest 7 m using distributed temperature sensing. Further, a novel approach was employed to estimate visibility in the lowest 2.5 m using a camera and an extended light source. These observations were supplemented by the existing conventional sensors at the site, including those along a 200-m tall tower. Comparison between the increased-resolution observations and their conventional counterparts show the errors to be small, giving confidence in the reliability of the techniques. The increased resolution of the observations subsequently allows for detailed investigations of fog growth and evolution. This includes the observation of large temperature inversions in the lowest metre (up to 5 K) and corresponding regions of (super)saturation where the fog formed. Throughout the two-week observation period, fog was observed twice at the conventional sensor height of 2.0 m. Two additional low-visibility events were observed in the lowest 0–0.5 m using the camera-based observations, but were missed by the conventional sensors. The camera observations also showed the growth of shallow radiation fog, forming in the lowest 0.5 m as early as two hours before it was observed at the conventional height of 2 m.
影响因子：
8.9
作者：
Maronga, B.;Bosveld, F. C.
通讯作者：
Bosveld, F. C.
影响因子：
8
作者：
Price, J. D.;Lane, S.;Clark, R.
通讯作者：
Clark, R.