NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to the exobase and describes the average observed behavior of temperature, eight species densities, and mass density via a parametric analytic formulation. The model inputs are location, day of year, time of day, solar activity, and geomagnetic activity. NRLMSIS 2.0 is a major, reformulated upgrade of the previous version, NRLMSISE‐00. The model now couples thermospheric species densities to the entire column, via an effective mass profile that transitions each species from the fully mixed region below ~70 km altitude to the diffusively separated region above ~200 km. Other changes include the extension of atomic oxygen down to 50 km and the use of geopotential height as the internal vertical coordinate. We assimilated extensive new lower and middle atmosphere temperature, O, and H data, along with global average thermospheric mass density derived from satellite orbits, and we validated the model against independent samples of these data. In the mesosphere and below, residual biases and standard deviations are considerably lower than NRLMSISE‐00. The new model is warmer in the upper troposphere and cooler in the stratosphere and mesosphere. In the thermosphere, N₂ and O densities are lower in NRLMSIS 2.0; otherwise, the NRLMSISE‐00 thermosphere is largely retained. Future advances in thermospheric specification will likely require new in situ mass spectrometer measurements, new techniques for species density measurement between 100 and 200 km, and the reconciliation of systematic biases among thermospheric temperature and composition data sets, including biases attributable to long‐term changes.

中文翻译：

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NRLMSIS 2.0：温度和中性物种密度的全大气经验模型

NRLMSIS®2.0是一个经验性大气模型，它从地面延伸到外底，并通过参数分析公式描述了观测到的温度，八种物种密度和质量密度的平均行为。模型输入是位置，一年中的某天，一天中的时间，太阳活动和地磁活动。NRLMSIS 2.0是对先前版本NRLMSISE-00的重大重新构造升级。该模型现在通过有效的质量剖面将热球物质的密度耦合到整个色谱柱，该有效的质量剖面将每种物质从海拔约70 km以下的完全混合区域过渡到海拔约200 km以上的扩散分离区域。其他变化包括将原子氧扩展到50 km，以及使用势能高度作为内部垂直坐标。我们吸收了广泛的新的中低层大气温度，O和H数据，以及从卫星轨道得出的全球平均热圈质量密度，我们针对这些数据的独立样本验证了该模型。在中层以下，残余偏差和标准偏差远低于NRLMSISE-00。新模型在对流层上部较暖，在平流层和中层较冷。在热层中，NNRLMSIS 2.0中₂和O的密度较低；否则，将很大程度上保留NRLMSISE-00热球。热球技术指标的未来发展可能需要新的现场质谱仪测量，100至200 km之间物种密度测量的新技术，以及热球温度和成分数据集之间系统偏差的协调，包括长期变化造成的偏差。