ACE SWEPAM/SWICS Level 3 Merged Solar Wind Proton Data

These data files contain 12-min resolution solar wind proton flow velocity (GSE, RTN and GSM components), scalar speed, density, and (radial component of) temperature, plus the alpha particle to proton density ratio. The data are typically from the SWEPAM instrument. But because SWEPAM has reduced sensitivity at the lowest energies, and at times underestimates the proton density, especially for very slow wind, proton density is sometimes culled from low-speed (.LT. ~350 km/s) intervals in the SWEPAM Level 2 data, and proton temperature may also be culled. More rarely, the solar wind velocity may also be culled, especially during periods of both high solar energetic particle background and high wind speeds. In these cases, SWICS-determined proton density and temperature, and possibly also flow speed (not velocity vectors), are included in the data records, with a flag to indicate whether, and which, SWICS parameters are in the records. As of July, 2012, data were available to the end of 2009.

本数据集包含12分钟分辨率的太阳风质子流速度（GSE、RTN与GSM分量）、标量速率、数密度，以及（径向分量的）温度，另有α粒子与质子的数密度之比。此类数据通常由SWEPAM仪器获取。但由于SWEPAM在最低能量段灵敏度下降，且有时会低估质子数密度，尤其在极慢太阳风事件中，因此SWEPAM二级数据中低速（.LT. ~350 km/s）时段的质子数密度有时会被剔除，质子温度也可能被剔除。更为罕见的是，太阳风速度也可能被剔除，尤其当太阳高能粒子背景与风速均处于较高水平时。在此类情形下，数据记录中会纳入SWICS测定的质子数密度、温度，以及可能的流速率（非速度矢量），并附带标记以说明数据记录中是否包含以及包含哪些SWICS参数。截至2012年7月，本数据集已覆盖至2009年底。