Evaluation of the Near Real-Time Forecasts Using a Global Nonhydrostatic Model during the CINDY2011/DYNAMO
Evaluation of the Near Real-Time Forecasts Using a Global Nonhydrostatic Model during the CINDY2011/DYNAMO
复制标题
CINDY2011/DYNAMO 期间使用全球非静水力模型的近实时预报评估
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
H. Taniguchi
中科院分区：
文献类型：
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作者：
T. Nasuno;K. Kikuchi;M. Nakano;Y. Yamada;Mikiko Ikeda;H. Taniguchi
通过与卫星和实地观测的比较，利用2011年印度洋季节内变率合作试验（CINDY 2011）/Madden-Julian振荡动力学（CNOO）活动，展示了非静力二十面体大气模式（NICAM）近实时预报的综合性能和潜在效用。在整个密集观测期间（IOP），每天使用NICAM的区域拉伸版本进行为期一周的预报，在热带印度洋（IO）上的最小网格尺寸为14公里。模拟的降水时间序列很好地代表了观测到的Madden-Julian振荡（MJO）事件的演变和传播，尽管在IO域（60 - 90°E，10°S - 10°N）发现平均超过30%的降水预测。强降水（> 40毫米日）的频率被高估，而弱降水的频率则被低估。结果表明，降水频率的偏差较甘岛观测值小，但对流层中低层干（~ 1g kg）和暖（~ 1 K）的偏差有所增加，尽管存在这些平均偏差，但对包括MJO事件在内的水汽和纬向风廓线的时间变化仍进行了合理的模拟。利用预报数据，研究了IOP期间的水分和能量收支。使用7天平均场的诊断捕获了MJO事件的观测特征。同时，通过网格分辨的高频变异性检测到整个IOP的水分的显著向上运输。这些高频效应和模拟的MJO或平均偏差之间的关系进行了讨论。
By comparison with satellite and field observations, the comprehensive performance and potential utility of near real-time forecasts using Nonhydrostatic Icosahedral Atmospheric Model (NICAM) are demonstrated by exploiting the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011) / Dynamics of the Madden–Julian Oscillation (DYNAMO) campaign. A week-long forecast was run each day using a regionally stretched version of NICAM, with the finest mesh size of 14 km over the tropical Indian Ocean (IO), throughout the intensive observation period (IOP). The simulated precipitation time series fairly represented the evolution and propagation of the observed Madden-Julian Oscillation (MJO) events, although a 30 % overprediction of precipitation over the IO domain (60 – 90°E, 10°S – 10°N) was found on average. Frequencies of strong (> 40 mm day) precipitation were overpredicted, while those of weak precipitation were underpredicted against satellite observations. Compared with the field observations at Gan Island, the biases in precipitation frequency were less obvious, whereas the growth of lower to middle tropospheric dry (~ 1 g kg) and warm (~ 1 K) biases were found. Despite these mean biases, temporal variations of the moisture and zonal wind profiles including the MJO events were reasonably simulated. Using the forecast data the moisture and energy budgets during the IOP were investigated. The diagnosis using the 7-day-mean fields captured the observed features of the MJO events. Meanwhile, significant upward transport of moisture by the grid-resolved high-frequency variability was detected throughout the IOP. The relationship between these high-frequency effects and the simulated MJO or mean biases is also discussed.