A Long-term Numerical Study of the Potential Predictability of Seasonal Mean Fields of Water Resource Variables using MRI/JMA-AGCM
A Long-term Numerical Study of the Potential Predictability of Seasonal Mean Fields of Water Resource Variables using MRI/JMA-AGCM
复制标题
使用 MRI/JMA-AGCM 对水资源变量季节平均场的潜在可预测性进行长期数值研究
DOI：
10.2151/jmsj.81.1041
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发表时间：
2003
影响因子：
3.1
通讯作者：
Keitaro Matsumaru
中科院分区：
文献类型：
--
作者：
T. Nakaegawa;M. Sugi;Keitaro Matsumaru
本文利用日本气象厅气象研究所的全球大气模式（MJ 98），研究了降水量-蒸发量（P-E）、陆地蓄水量、雪水当量和径流量四个水资源量的季节平均场的潜在可预报性（在海表温度（SST）预报良好的情况下的最大可能可预报性）。50-年（1949-1998年）的集合积分，从六个不同的初始条件，强迫相同的SST和海冰覆盖。SST强迫变率的季节平均场方差比，总的变率，计算来衡量潜在的可预报性的四个变量。P-E的方差比一般在热带较高，而在热带外较低.陆地总水储量的潜在可预报性的地理模式与P-E相似，因为它是进入地表的净水通量。DJF的雪水当量的方差比与高纬度降水的方差比一样低。然而，阿拉斯加湾沿海地区的MAM值很高，尽管其他地区仍然很低。径流方差比的地理分布与陆地总蓄水量的地理分布具有相似的特征，但前者的值略低于后者。在热带外的某些地区发现了高的方差比。奇异值分解（SVD）分析表明，P-E和雪水当量的比值是由于热带海温强迫的遥相关，而陆地总储水量的高方差比是由于其持续性。
Using the Meteorological Research Institute of Japan Meteorological Agency, atmospheric global model (MJ98), the potential predictability is investigated (maximum possible predictability when sea surface temperature (SST) is perfectly predicted) of the seasonal mean fields of four water resource variables, i.e. precipitation minus evaporation (P - E), the terrestrial water storage, snow water equivalence, and runoff. 50-year (1949-1998) ensemble integrations are performed from six different initial conditions, forced with the same SST and sea ice cover. The seasonal mean field variance ratios of the SST-forced variability, to the total variability, are computed to measure potential predictability of the four variables. The variance ratios of P - E are generally high in the tropics, but low in the extratropics. The geographical pattern of potential predictability of the total terrestrial water storage is similar to that of P - E, since it is the net water flux into the ground surface. The variance ratios of snow water equivalence were as low in DJF as those of precipitation at high latitudes. However, the values in the coastal area of the Gulf of Alaska is high in MAM, although the other regions remained low. The geographical distribution of the variance ratio of runoff, has similar features to that of the total terrestrial water storage, but the values of the former are slightly lower than those of the latter. High variance ratios are found in some areas of the extratropics. Singular value decomposition (SVD) analysis suggests that the ratios of P - E, and snow water equivalence, are due to the teleconnection forced by the tropical SST, while the higher variance ratio of the total terrestrial water storage is due to its persistence.