Seasonal polar motion excitation from numerical models of atmosphere, ocean, and continental hydrosphere
Seasonal polar motion excitation from numerical models of atmosphere, ocean, and continental hydrosphere
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DOI：
10.1029/2009jb007127
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发表时间：
2010-10
影响因子：
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通讯作者：
H. Dobslaw;R. Dill;A. Grötzsch;A. Brzeziński;Maik Thomas
中科院分区：
文献类型：
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作者：
H. Dobslaw;R. Dill;A. Grötzsch;A. Brzeziński;Maik Thomas
[1]来自大气、海洋和陆地储水量的有效角动量函数是由欧洲中期天气预报中心的大气数据和相应的海洋环流和潮汐模式以及陆地表面和排放模式（LSDM）模拟得到的。子系统之间的质量交换是通过淡水通量来实现的，这使得海洋总质量每年的变化占主导地位。海洋总质量的变化对年摆动的海洋激励的正向和逆行分量的影响都接近1毫角秒（mas），而由LSDM得出的陆地水流的运动项贡献则小3个数量级。由于与大地激励的差异并没有实质性地减少，并且区域分解表明季节极运动激励的贡献在整体上相互补偿的空间变异性很大，因此得出的结论是，所有子系统中剩余的模式误差仍然抑制了季节激励预算的关闭。
[1] Effective angular momentum functions from atmosphere, oceans, and terrestrial water storage are obtained from European Centre for Medium-Range Weather Forecasts atmospheric data and corresponding simulations with the Ocean Model for Circulation and Tides and the Land Surface and Discharge Model (LSDM). Mass exchanges among the subsystems are realized by means of freshwater fluxes, causing the total ocean mass to vary predominantly annually. Variations in total ocean mass affect the oceanic excitations of the annual wobble by almost 1 milliarc second (mas) for both prograde and retrograde components, whereas the motion term contributions of terrestrial water flow derived from LSDM are found to be 3 orders of magnitude smaller. Since differences to geodetic excitations are not substantially reduced and regional decompositions demonstrate the large spatial variability of contributions to seasonal polar motion excitation that compensate each other when integrated globally, it is concluded that the closure of the seasonal excitation budget is still inhibited by remaining model errors in all subsystems.