Measuring Global Signals in the Potential Gradient at High Latitude Sites
Measuring Global Signals in the Potential Gradient at High Latitude Sites
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DOI：
10.3389/feart.2020.614639
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
J. Tacza;K. Nicoll;E. Macotela;M. Kubicki;A. Odzimek;J. Manninen
中科院分区：
文献类型：
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作者：
J. Tacza;K. Nicoll;E. Macotela;M. Kubicki;A. Odzimek;J. Manninen
先前的研究表明，全球电路的研究可以与气候变化研究相关，这可以通过在晴朗天气条件下测量地表附近的电势梯度来完成。然而，由于不同的局部效应（例如污染、对流过程），势梯度测量结果可能存在很大差异。为了尽量减少这些影响，可以在人为影响较小的偏远地区进行潜在梯度测量。在这项工作中，我们展示了南半球和北半球高纬度五个站的潜在梯度测量结果。这是对来自南极洲哈雷的新数据集的首次描述；和芬兰索丹屈莱。极冠电离层电位的影响在某些极地站可能很显着，这里进行的详细分析表明对哈雷和索丹屈拉表面电位梯度的影响可以忽略不计。还报告了确定积雪地点晴朗天气条件的新标准，表明低至 3 m/s 的风速可以扬起雪粒，并且测量地点的获取是确定该阈值风速的重要因素。对公平天气条件下电势梯度的每日和季节性分析表明，与全球电路的“通用”卡内基曲线非常一致，特别是在哈雷。这表明，可能存在磁力和太阳影响的高纬度地点也可以为全球电路的研究提供具有全球代表性的测量地点。
Previous research has shown that the study of the global electrical circuit can be relevant to climate change studies, and this can be done through measurements of the potential gradient near the surface in fair weather conditions. However, potential gradient measurements can be highly variable due to different local effects (e.g., pollution, convective processes). In order to try to minimize these effects, potential gradient measurements can be performed at remote locations where anthropogenic influences are small. In this work we present potential gradient measurements from five stations at high latitudes in the Southern and Northern Hemisphere. This is the first description of new datasets from Halley, Antarctica; and Sodankyla, Finland. The effect of the polar cap ionospheric potential can be significant at some polar stations and detailed analysis performed here demonstrates a negligible effect on the surface potential gradient at Halley and Sodankyla. New criteria for determination of fair weather conditions at snow covered sites is also reported, demonstrating that wind speeds as low as 3 m/s can loft snow particles, and that the fetch of the measurement site is an important factor in determining this threshold wind speed. Daily and seasonal analysis of the potential gradient in fair weather conditions shows great agreement with the “universal” Carnegie curve of the global electric circuit, particularly at Halley. This demonstrates that high latitude sites, at which the magnetic and solar influences can be present, can also provide globally representative measurement sites for study of the global electric circuit.