A model providing long-term data sets of energetic electron precipitation during geomagnetic storms
A model providing long-term data sets of energetic electron precipitation during geomagnetic storms
复制标题
提供地磁风暴期间高能电子沉淀长期数据集的模型
DOI：
10.1002/2015jd024212
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Van De Kamp M
中科院分区：
文献类型：
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作者：
Van De Kamp M
高能电子降水（EEP）引起的太阳变率对极地大气和气候的影响仍然是一个悬而未决的问题，主要原因是缺乏可用于化学-气候模式的长期EEP强迫数据集。基于此，我们开发了一种30-1000 keV辐射带驱动的EEP模型。该模型基于2002-2012年近地轨道POES卫星的降水数据，并对等离子体层结构进行了经验描述，两者均按地磁指数进行了缩放。该地磁指数是模型的唯一输入，可以是dstorap。因此，该模型可用于计算1957年（Dst）或1932年（Ap）以后的沉淀电子的能量通量谱，时间分辨率为1天。该模式的结果与2002-2012年期间的EEP观测结果比较好。使用该模型避免了在质子污染的测量数据集中发现的挑战。结果表明，该模式结果可用于生成辐射带EEP的首个80年大气电离率数据集。该能量范围内降水的影响主要见于海拔70 ~ 110 km处。科学界可获得的电离率数据集将能够模拟EEP对大气和气候的影响，并具有实际的EEP变率。由于模型第一个版本的局限性，结果很可能代表了对总EEP效应的低估。
The influence of solar variability on the polar atmosphere and climate due to energetic electron precipitation (EEP) has remained an open question largely due to lack of a long‐term EEP forcing data set that could be used in chemistry‐climate models. Motivated by this, we have developed a model for 30–1000 keV radiation belt driven EEP. The model is based on precipitation data from low Earth orbiting POES satellites in the period 2002–2012 and empirically described plasmasphere structure, which are both scaled to a geomagnetic index. This geomagnetic index is the only input of the model and can be eitherDstorAp. Because of this, the model can be used to calculate the energy‐flux spectrum of precipitating electrons from 1957 (Dst) or 1932 (Ap) onward, with a time resolution of 1 day. Results from the model compare well with EEP observations over the period of 2002–2012. Using the model avoids the challenges found in measured data sets concerning proton contamination. As demonstrated, the model results can be used to produce the first ever >80 year long atmospheric ionization rate data set for radiation belt EEP. The impact of precipitation in this energy range is mainly seen at altitudes 70–110 km. The ionization rate data set, which is available for the scientific community, will enable simulations of EEP impacts on the atmosphere and climate with realistic EEP variability. Due to limitations in this first version of the model, the results most likely represent an underestimation of the total EEP effect.