GRAPES模式后处理技术改进应用研究

详细梳理了GRAEPS模式后处理系统的计算方案,进行了GRAPES模式后处理中海平面气压计算方案的改进,温度垂直插值方案的改进以及位势高度的垂直插值外插方案的改进等。假定温度廓线随地形高度变化并满足静力平衡条件,对海平面气压及位势高度外插进行改进,改进后海平面气压和低层等压面的位势高度场在青藏高原和南美洲西部等大地形处改进明显,均方根误差和距平相关系数改进较大并通过显著性检验。对温度垂直插值采用的原始插值层进行改进,使得高层等压面温度场的准确性进一步提高,统计检验评分在各区域都有不同程度的提高,尤其是热带地区和东亚地区高层温度场改善明显。这些都为模式产品用户提供了更可靠的数值模式产品。

Improvement and Application of Post-Processing Technology in GRAPES Model

The calculation schemes of the post processing system of the GRAEPS model are studied in detail, and the sea level pressure calculation scheme and the temperature vertical interpolation scheme in the GRAPES post processing system, and the extrapolation scheme in the vertical interpolation of potential height are improved. GRAPES mostly adopts the cubic spline function method to vertical interpolation, and the interpolation precision can be guaranteed. However, the sea level pressure calculation scheme and the extrapolation scheme below the terrain in the previous GRAPES post processing system is not detailed enough. In this paper, assuming that the temperature profile varied with terrain height and the model atmosphere satisfied the static equilibrium condition, the sea level pressure calculation scheme and the original interpolation layer of sea level pressure and temperature used for vertical interpolation is optimized, so that the accuracy of sea level pressure and high level temperature is further improved. The statistical test scores are improved in different regions, and the sea level pressure and the high level temperature field in the tropics and East Asia improved significantly and passed the significance test. The extrapolation schemes of potential height are optimized, and the low level potential heights are improved significantly in large terrains such as the Qinghai Tibet Plateau and the western South America. Statistical results show that this scheme has significant improvements in the anomaly correlation coefficient and root mean square error in the low level fields in various regions of the world. These provide more reliable numerical model products for users.