An Alternative Methodology of Fair‐Weather Identification for Ground‐Based Measurement of AEF at the Polar Region
An Alternative Methodology of Fair‐Weather Identification for Ground‐Based Measurement of AEF at the Polar Region
复制标题
极地 AEF 地面测量的晴天识别替代方法
DOI：
10.1029/2021jd035732
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Omiya Satoshi
中科院分区：
文献类型：
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作者：
Minamoto Yasuhiro;Kamogawa Masashi;Kadokura Akira;Sato Mitsuteru;Omiya Satoshi
我们提出了一种新方法来区分源自全球电路和当地气象引起的 AEF 变化的大气电场 (AEF) 变化。该方法通过比较两个不同高度处测得的AEF值，识别出包含带电吹雪颗粒引起的干扰的AEF数据，并提供晴天AEF数据。由于带负电的吹雪颗粒碰撞电场磨机的传感器电极，在强风期间测量了强烈的正（晴天方向）视在 AEF。一般来说，吹雪颗粒的体积密度随着高度的增加而迅速减小。因此，在两个高度处测得的AEF值是不同的。当风速为 6 m/s 或更高时，两个高度处测量的 AEF 值之间的差异会增加。同时，统计分析显示，昭和站有云和无云的情况下的 AEF 均小于约 1 V/m，可以忽略不计。此外，昭和站的案例研究发现云扩展/消散与 AEF 之间没有关系。因此，我们提出了一种实用方法，通过在极地地区（例如昭和站）观测到的两个高度的 AEF 值和风速来识别晴天条件。当我们以昭和站全部数据在风速小于6.0 m/s的情况下，1.4和10 m高度处观测到的AEF差异在±20 V/m以内为标准时，其中24%被确定为晴天数据。
We present a novel method to discriminate atmospheric electric field (AEF) variations originating from the global electrical circuit and local meteorological‐induced AEF variations. By comparing the AEF values measured at two different heights, the method identifies the AEF data including disturbances caused by charged blowing snow particles, and provides the fair‐weather AEF data. The intense positive (fair‐weather direction) apparent AEF was measured during strong winds because of the collision of negatively charged blowing snow particles into the sensor electrode of the electric field mill. In general, the volume density of blowing snow particles rapidly decreases with increasing height. Therefore, measured AEF values at the two heights were different. The difference between AEF values measured at the two heights increased at a wind speed of 6 m/s or more. Meanwhile, the statistical analysis showed that the AEF with and without clouds was less than approximately 1 V/m at Syowa Station, which is negligible. In addition, this case study at Syowa Station found no relationship between cloud extension/dissipation and AEF. Accordingly, we propose a practical method to identify the fair‐weather conditions by the AEF values at two heights and wind speed observed in the polar region, such as at Syowa Station. When we employ criteria that the difference between the AEF observed at the 1.4 and 10 m heights was within ±20 V/m under the wind speed with less than 6.0 m/s to the whole data at Syowa Station, 24% of them were identified as fair‐weather data.