Spacecraft potential variations of the Swarm satellites at low Earth orbital altitudes  

作　　者：HaiCheng Jiang Chao Xiong Fan Yin YuHao Zheng ZiYuan Zhu Rui Yan Yi Wen Liu 

机构地区：[1]Department of Space Physics,Electronic Information School,Wuhan University,Wuhan 430072,China [2]Hubei Luojia Laboratory,Wuhan 430079,China [3]National Institute of Natural Hazards,the Ministry of Emergency Management of China,Beijing 100085,China [4]School of Physics and Electronic Information,Shangrao Normal University,Shangrao 334001,China

出　　处：《Earth and Planetary Physics》2023年第4期421-435,共15页地球与行星物理（英文版）

基　　金：supported by the National Key R&D Program of China (Grant No. 2022YFF0503700);the special found of Hubei Luojia Laboratory (220100011);supported by the Dragon 5 cooperation 2020-2024 (project no. 59236)

摘　　要：In this study, we provide the first detailed analysis of variations in the spacecraft potential (Vs) of the three Swarm satellites, which are flying at about 400-500 km. Unlike previous studies that have investigated extreme charging events, usually with spacecraft potentials as negative as −100 V, this study is focused on variations of Swarm Vs readings, which fall within a few negative volts. The Swarm observations show that spacecraft at low Earth orbital (LEO) altitudes are charged only slightly negatively, varying between −7 V and 0 V, with the majority of recorded potentials at these altitudes clustering close to −2 V. However, a second peak of Vs data is found at −5.5 V, though the event numbers for these more-negative observations are less, by an order of magnitude, than for incidents near the −2 V peak. These two distinct Vs peaks suggest two different causes. We have thus divided the Swarm spacecraft Vs data into two categories: less-negatively charged (−5 < Vs < 0 V) and more-negatively-charged (−6.5 < Vs < −5 V). These two Vs categories exhibit different spatial and temporal distributions. The Vs observations in the first category remain relatively closer to 0 V above the magnetic equator, but become much more negative at low and middle latitudes on the day side;at high latitudes, these first-category Vs readings are relatively more-negative during local summer. Second-category Vs events cluster into two bands at the middle latitudes (between ±20°-50° magnetic latitude), but with slightly more negative readings at the South Atlantic Anomaly (SAA) region;at high latitudes, these rarer but more-negative second-category Vs events exhibit relatively more-negative values during local winter, which is opposite to the seasonal pattern seen in the first category. By comparing Vs data to the distributions of background plasma density at Swarm altitudes, we find for the first category that more-negative Vs readings are recorded at regions with higher background plasma density, while for the s

关 键 词：spacecraft potentia low Earth orbit satellites Swarm mission particle precipitation 

分 类 号：V412.41[航空宇航科学与技术—航空宇航推进理论与工程]