HYSPLIT模式轨迹计算误差分析

Trajectory calculation error assessment for HYSPLIT

基于NCEP 1°×1°再分析资料GDAS和NCEP2.5°×2.5°再分析资料GBL,利用美国NOAA空气资源实验室ARL研发的一种用于计算和分析大气污染物输送、扩散轨迹的混合单粒子拉格朗日综合轨迹模式HYSPLIT,对2010年3月12日12时和田站距地100 m高度空气质点的3 d前向轨迹进行了模拟,分析了轨迹计算中的积分误差和分辨率误差.此次轨迹模拟试验中,积分误差对轨迹计算误差的贡献很小.随着积分时间的延长,积分误差略有增大.积分误差并未随着驱动数据分辨率的提高而减小.分辨率误差在积分的各个时刻并不相同,它与地形高度与天气系统有关.在轨迹模式中,轨迹计算基于风速在时间和空间上的线性插值,轨迹模拟的不确定性也与插值有关.使用不同分辨率的驱动数据对轨迹计算结果影响显著,分辨率误差对轨迹计算误差的贡献远大于积分过程中截断近似等带来的积分误差.

Based upon GDAS and GBL NCEP reanalysis data with resolution 1°×1°and 2. 5°×2. 5°respectively,the trajectory of the air mass at 100 m altitude over Hetian meteorological station is simulated by HYSPLIT（ Hybrid Single Particle Lagrangian Integrated Trajectory Model）,which is developed by Air Source Laboratory of NOAA,to estimate the effect of integration error and resolution error on the trajectory calculation error. The contribution of the integration error is found to be very small,which increases slightly with the integration time length and has no relation to the resolution of the meteorological data. The resolution error varies at different time point,and is found to be related to the topography,the weather system and the interpolation. The simulated trajectories using datasets with different resolution differed with each other significantly,indicating that the resolution error contributes more to the trajectory calculation error than calculation error.