Forecasting GOES 15 >2 MeV Electron Fluxes From Solar Wind Data and Geomagnetic Indices
Forecasting GOES 15 >2 MeV Electron Fluxes From Solar Wind Data and Geomagnetic Indices
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DOI：
10.1029/2019sw002416
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
Colin Forsyth;C. E. Watt;M. Mooney;I. J. Rae;S. Walton;R. Horne
中科院分区：
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作者：
Colin Forsyth;C. E. Watt;M. Mooney;I. J. Rae;S. Walton;R. Horne
空间天气预报员将地球同步轨道上大于2 MeV电子的通量用作低、中或地球同步轨道上航天器受损风险增加的一个关键指标。我们提出了一种方法，该方法使用单个输入数据集（太阳风数据或地磁指数）超过给定阈值的时间量，以在最多10天内产生GEO超过1，000或10，000 cm−2 s−1 sr−1的>2 MeV通量的确定性和概率性预测。通过将我们的预测与2014年至2016年期间GOES 15的测量通量进行比较，我们分别通过最大化受试者操作特征（ROC）和Brier技能得分来确定性和概率性预测的最佳预测阈值。训练数据集给出的ROC峰值分数为0.71至0.87，Brier技能峰值分数为-0.03至0.32。来自AL的预测给出了最高的技能分数，预测时间长达6天。AL、太阳风压或SYM-H在7-10天内给出最高的技能分数。命中率范围超过56-89%，误报率为11- 53%。应用于2012年，2013年和2017年，我们的最佳预测命中率为56-83%，误报率为10- 20%。进一步调整预测可能会改善这些情况。我们的命中率是可比的业务通量预测，包括通量测量，但我们的误报率更高。这一概念证明表明，地球同步电子通量可以在一定程度上成功预测，而无需将持久性元素纳入预测。
The flux of > 2 MeV electrons at geosynchronous orbit is used by space weather forecasters as a key indicator of enhanced risk of damage to spacecraft in low, medium, or geosynchronous Earth orbits. We present a methodology that uses the amount of time a single input data set (solar wind data or geomagnetic indices) exceeds a given threshold to produce deterministic and probabilistic forecasts of the >2 MeV flux at GEO exceeding 1,000 or 10,000 cm−2 s−1 sr−1 within up to 10 days. By comparing our forecasts with measured fluxes from GOES 15 between 2014 and 2016, we determine the optimum forecast thresholds for deterministic and probabilistic forecasts by maximizing the receiver‐operating characteristic (ROC) and Brier skill scores, respectively. The training data set gives peak ROC scores of 0.71 to 0.87 and peak Brier skill scores of −0.03 to 0.32. Forecasts from AL give the highest skill scores for forecasts of up to 6 days. AL, solar wind pressure, or SYM‐H give the highest skill scores over 7–10 days. Hit rates range over 56–89% with false alarm rates of 11–53%. Applied to 2012, 2013, and 2017, our best forecasts have hit rates of 56–83% and false alarm rates of 10–20%. Further tuning of the forecasts may improve these. Our hit rates are comparable to those from operational fluence forecasts, that incorporate fluence measurements, but our false alarm rates are higher. This proof‐of‐concept shows that the geosynchronous electron flux can be forecast with a degree of success without incorporating a persistence element into the forecasts.