本文对海洋气象漂流观测仪实测、CMA最佳路径数据集、第5代全球气象再分析产品(ERA5)、交叉检验多平台融合矢量风场(CCMP)四种资料的海面风在超强台风“利奇马”期间的变化特征进行分析。ERA5、CCMP两种分析/再分析风资料与实测风的对...本文对海洋气象漂流观测仪实测、CMA最佳路径数据集、第5代全球气象再分析产品(ERA5)、交叉检验多平台融合矢量风场(CCMP)四种资料的海面风在超强台风“利奇马”期间的变化特征进行分析。ERA5、CCMP两种分析/再分析风资料与实测风的对比分析表明:(1)风速:当风力<10级时,漂流观测仪轨迹上的ERA5、CCMP风速较漂流观测仪实测风速偏小;将漂流观测仪实测风速订正到10 m高度,风力≤5级时偏差(Bias)绝对值最小,ERA5(CCMP)为4.3 m s^(-1)(4.6 m s^(-1)),风力为7~9级时Bias绝对值最大,约9.2~10.2 m s^(-1);“利奇马”近中心海域ERA5、CCMP最大风速较CMA最佳路径数据集偏小,ERA5(CCMP)偏小约10.7 m s^(-1)(4.6 m s^(-1));ERA5(CCMP)最大风速极值较CMA最佳路径数据集偏低54.5%(12.7%)。(2)风向:ERA5、CCMP与漂流观测仪实测风向相关系数接近于0;风力≤5级时风向较实测偏右,风力>5级时偏左。(3)ERA5、CCMP风向、风速在“利奇马”近中心海域偏差明显,远离中心海域二者吻合度较高。通过对ERA5、CCMP资料进一步分析发现:CCMP能清楚描述热带气旋风场结构及演变过程,“利奇马”为超强台风时结构参数η=Vr/Vmax分布上有闭合环状结构,表明该区域有环状大风速带;“利奇马”强迫时间T_f分布于移动路径两侧,ERA5(CCMP)最大强迫时间为45 h(54 h)。展开更多
POM (Princeton ocean model) tentatively taken as the ocean part of an ocean-land atmosphere coupled modcl is verified for the ultimate purpose of studying the landfall process of tropical cyclone (TC) in the western N...POM (Princeton ocean model) tentatively taken as the ocean part of an ocean-land atmosphere coupled modcl is verified for the ultimate purpose of studying the landfall process of tropical cyclone (TC) in the western North Pacific. The POM is tested with monthly mean wind stress in the summer and given lateral boundary conditions. The results indicate that the equilibrium state of the ocean is in accordance with the climate mean, with the error in sea surface temperature (salinity) less than 0.5 ℃ (0.5). The simulated occan currents are reasonable as well.Several numerical experiments are designed to verify the oceanic response to a stationary or moving TC. It is found that the results agree fairly well with the previous work, including both the drop magnitude and the distribution ofsca temperature. Compared with the simple two-layer ocean model used by some other studies, the response of the ocean to a TC is more logical here. The model is also verified in a real case with a TC passing the neighborhood of a buoy station. It is shown that the established ocean model can basically reproduce the sea surface temperature change as observed.展开更多
文摘本文对海洋气象漂流观测仪实测、CMA最佳路径数据集、第5代全球气象再分析产品(ERA5)、交叉检验多平台融合矢量风场(CCMP)四种资料的海面风在超强台风“利奇马”期间的变化特征进行分析。ERA5、CCMP两种分析/再分析风资料与实测风的对比分析表明:(1)风速:当风力<10级时,漂流观测仪轨迹上的ERA5、CCMP风速较漂流观测仪实测风速偏小;将漂流观测仪实测风速订正到10 m高度,风力≤5级时偏差(Bias)绝对值最小,ERA5(CCMP)为4.3 m s^(-1)(4.6 m s^(-1)),风力为7~9级时Bias绝对值最大,约9.2~10.2 m s^(-1);“利奇马”近中心海域ERA5、CCMP最大风速较CMA最佳路径数据集偏小,ERA5(CCMP)偏小约10.7 m s^(-1)(4.6 m s^(-1));ERA5(CCMP)最大风速极值较CMA最佳路径数据集偏低54.5%(12.7%)。(2)风向:ERA5、CCMP与漂流观测仪实测风向相关系数接近于0;风力≤5级时风向较实测偏右,风力>5级时偏左。(3)ERA5、CCMP风向、风速在“利奇马”近中心海域偏差明显,远离中心海域二者吻合度较高。通过对ERA5、CCMP资料进一步分析发现:CCMP能清楚描述热带气旋风场结构及演变过程,“利奇马”为超强台风时结构参数η=Vr/Vmax分布上有闭合环状结构,表明该区域有环状大风速带;“利奇马”强迫时间T_f分布于移动路径两侧,ERA5(CCMP)最大强迫时间为45 h(54 h)。
基金sponsored by the National Natural Science Foundation of China under contrct Nos 40575030,40275018 and 49975014.
文摘POM (Princeton ocean model) tentatively taken as the ocean part of an ocean-land atmosphere coupled modcl is verified for the ultimate purpose of studying the landfall process of tropical cyclone (TC) in the western North Pacific. The POM is tested with monthly mean wind stress in the summer and given lateral boundary conditions. The results indicate that the equilibrium state of the ocean is in accordance with the climate mean, with the error in sea surface temperature (salinity) less than 0.5 ℃ (0.5). The simulated occan currents are reasonable as well.Several numerical experiments are designed to verify the oceanic response to a stationary or moving TC. It is found that the results agree fairly well with the previous work, including both the drop magnitude and the distribution ofsca temperature. Compared with the simple two-layer ocean model used by some other studies, the response of the ocean to a TC is more logical here. The model is also verified in a real case with a TC passing the neighborhood of a buoy station. It is shown that the established ocean model can basically reproduce the sea surface temperature change as observed.
