SAMI3 data in netCDF format (2019-Mar-25)

SAMI3 (Sami3 is Also a Model of the Ionosphere) is a seamless, three-dimensional, physics-based model of the ionosphere (Huba et al, 2008). It is based on SAMI2, a two-dimensional model of the ionosphere (Huba et al., 2000). <br><br>SAMI3 models the plasma and chemical evolution of seven ion species (H⁺, He⁺, N⁺, O⁺, N⁺₂, NO⁺ and O⁺₂). The temperature equation is solved for three ion species (H⁺, He⁺ and O⁺) and for the electrons. Ion inertia is included in the ion momentum equation for motion along the geomagnetic field. This is important in modeling the topside ionosphere and plasmasphere where the plasma becomes collisionless. <br><br>SAMI3 includes 21 chemical reactions and radiative recombination, and uses a nonorthogonal, nonuniform, fixed grid for the magnetic latitude range +/- 89 degrees.. <br><br><b>Drivers</b><br>Neutral composition, temperature, and winds: NRLMSISE00 (Picone et al., 2002) and HWM14 (Drob et al., 2015). <br>Solar radiation: Flare Irradiance Spectral Model version 2 (FISM v2)<br>Magnetic field: Richmond apex model [Richmond, 1995]. <br>Neutral wind dynamo electric field: Determined from the solution of a 2D potential equation [Huba et at., 2008]. <br>For the SAMI3/Weimer configuration: High latitude electric field: calculated from the empirical Weimer model for the potential. <br>For the SAMI3/AMPERE configuration: High latitude electric field: calculated using the Magnetosphere-Ionosphere Coupling solver (MIX) developed by Merkin and Lyon (2010). The inputs to MIX are SAMI3's internal conductances, plus field-aligned current observations from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE), derived from the 66+ satellite Iridium NEXT constellation's engineering magnetometer data. This potential calculation is described in Chartier et al (2022). <br><br>For ease of use, SAMI3 output is remapped to a regular grid using the Earth System Modeling Framework by Hill et al (2004)SAMI3（Sami3亦是电离层模型，Sami3 is Also a Model of the Ionosphere）是一款无缝、三维、基于物理原理的电离层模型（Huba等，2008）。其基于SAMI2——一款二维电离层模型（Huba等，2000）。<br><br>SAMI3可模拟7种离子（H⁺、He⁺、N⁺、O⁺、N₂⁺、NO⁺及O₂⁺）的等离子体与化学演化过程。该模型针对H⁺、He⁺、O⁺三种离子以及电子求解温度方程；沿地磁场运动的离子动量方程中纳入了离子惯性项，这一设计对模拟等离子体无碰撞的电离层顶部与等离子体层具有重要意义。<br><br>SAMI3包含21种化学反应与辐射复合过程，并针对±89°的磁纬度范围采用非正交、非均匀的固定网格。<br><br><b>驱动源项</b><br>中性成分、温度与风场：采用NRLMSISE00模型（Picone等，2002）与HWM14模型（Drob等，2015）。<br>太阳辐射：采用耀斑辐照度光谱模型第2版（FISM v2）<br>磁场：采用Richmond顶点模型（Richmond，1995）。<br>中性风发电机电场：通过二维电势方程的求解结果确定（Huba等，2008）。<br><br>针对SAMI3/Weimer耦合配置：高纬电场由经验性的Weimer电势模型计算得到。<br>针对SAMI3/AMPERE耦合配置：高纬电场采用Merkin与Lyon（2010）开发的磁层-电离层耦合求解器（MIX）进行计算。MIX的输入参数包括SAMI3的内部电导率，以及来自主动磁层与行星电动力学响应实验（AMPERE）的场向电流观测数据——该数据源自66颗以上的铱星NEXT星座工程磁力计观测资料。该电势计算方法由Chartier等（2022）详述。<br><br>为便于使用，SAMI3的输出结果通过Hill等（2004）提出的地球系统建模框架（Earth System Modeling Framework）重映射至规则网格。