Short-term polar motion forecasts from earth system modeling data
Short-term polar motion forecasts from earth system modeling data
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DOI：
10.1007/s00190-010-0391-5
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发表时间：
2010-06
影响因子：
4.4
通讯作者：
R. Dill;H. Dobslaw
中科院分区：
文献类型：
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作者：
R. Dill;H. Dobslaw
在2003-2008年的后测实验中，根据大气、海洋和大陆水圈的预测状态，对未来10天内的极地运动进行了预测。地球物理流体中的高频质量变化是目前使用的IERS公告A极移统计预测方法中未考虑的宽带随机信号的主要原因。考虑到EAM函数的预测模式状态的基础上，来自ECMWF中期预报和相应的LSDM和OMCT模拟，预测误差减少了26%。模式组合的有效预报长度为7天，主要受大气风场预报精度的限制。最高的改进被发现为预测天4-5与极地运动激励功能的预测技能分数提高了一个因子高达5。虽然公告A预测只能解释前10天内观察到的方差高达40%，但有一半的模型预测达到40%至80%之间的相对解释方差。
Polar motion predictions for up to 10 days into the future are obtained from predicted states of the atmosphere, ocean and continental hydrosphere in a hind-cast experiment covering 2003–2008. High-frequency mass variations within the geophysical fluids are the main cause of wide-band stochastic signals not considered in the presently used statistical prediction approach of IERS bulletin A for polar motion. Taking EAM functions based on forecasted model states, derived from ECMWF medium-range forecasts and corresponding LSDM and OMCT simulations, into account the prediction errors are reduced by 26%. The effective forecast length of the model combination is found to be 7 days, primarily limited by the accuracy of the forecasted atmospheric wind fields. Highest improvements are found for forecast days 4–5 with prediction skill scores of the polar motion excitation functions improved by a factor up to 5. Whereas bulletin A forecasts can explain the observed variance within the first 10 days only by up to 40%, half of the model forecasts reach relative explained variances between 40 and 80%.