Comparison of Field‐Aligned Current Responses to HSS/SIR, Sheath, and Magnetic Cloud Driven Geomagnetic Storms

The time delay from an interplanetary driver arriving at the magnetopause to response in ionosphere has never been quantified separately for different types of storm drivers. This study investigates storms driven by high-speed streams and associated stream interaction regions (HSS/SIR), or coronal mass ejection sheaths magnetic clouds (MC). total field-aligned current (FAC) SME index lag Newell coupling function (NCF) 40 ± 10 min during HSS/SIR sheaths, 60 MCs. correlation coefficient between FAC NCF reaches maximum value as is averaged over preceding 80 sheath, 90 HSS/SIR, 140 MC storms.