A TRMM/GPM retrieval of the total mean generator current for the global electric circuit
A TRMM/GPM retrieval of the total mean generator current for the global electric circuit
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全局电路总平均发电机电流的 TRMM/GPM 检索
DOI：
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发表时间：
2017
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通讯作者：
C. Kalb
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作者：
Michael Peterson;W. Deierling;Chuntao Liu;D. Mach;C. Kalb
被动微波电场反演算法的专用卫星版本（Peterson 等人，2015）应用于热带降雨测量任务（TRMM）和全球降水测量（GPM）卫星的观测，以估计全球电路（GEC）的发电机电流并计算其时间变化。通过整合从全球带电云中检索到的威尔逊电流，我们估计总平均电流在 1.4 kA（假设 ER-2 测量到的带电云产生向下电流的 7% 的比例具有代表性）到 1.6 kA（假设所有带电云都对 GEC 做出贡献）之间。这些当前的估计来自所有类型的对流天气，没有偏好，包括电阵雨云 (ESC)。检索到的发电机电流的日分布与卡内基曲线非常一致（RMS 差异：1.7%）。总平均发电机电流的时间变化范围从半年时间尺度上的 110%（每年时间尺度上的 29%）到十年时间尺度上的 7.5%，对马登-朱利安涛动和厄尔尼诺南方涛动有显着响应。除陆地热带烟囱外，洋流的地理分布还包括海洋区域的重要贡献。与非洲相比，美洲和亚洲烟囱的相对重要性与最好的现代地面观测结果一致，并进一步凸显了 ESC 对于 GEC 的重要性。
A specialized satellite version of the passive microwave electric field retrieval algorithm (Peterson et al., 2015) is applied to observations from the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellites to estimate the generator current for the Global Electric Circuit (GEC) and compute its temporal variability. By integrating retrieved Wilson currents from electrified clouds across the globe, we estimate a total mean current of between 1.4 kA (assuming the 7% fraction of electrified clouds producing downward currents measured by the ER‐2 is representative) to 1.6 kA (assuming all electrified clouds contribute to the GEC). These current estimates come from all types of convective weather without preference, including Electrified Shower Clouds (ESCs). The diurnal distribution of the retrieved generator current is in excellent agreement with the Carnegie curve (RMS difference: 1.7%). The temporal variability of the total mean generator current ranges from 110% on semi‐annual timescales (29% on an annual timescale) to 7.5% on decadal timescales with notable responses to the Madden‐Julian Oscillation and El Nino Southern Oscillation. The geographical distribution of current includes significant contributions from oceanic regions in addition to the land‐based tropical chimneys. The relative importance of the Americas and Asia chimneys compared to Africa is consistent with the best modern ground‐based observations and further highlights the importance of ESCs for the GEC.