Observed winter cyclone tracks in the northern hemisphere in re‐analysed ECMWF data
Observed winter cyclone tracks in the northern hemisphere in re‐analysed ECMWF data
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重新分析 ECMWF 数据中观测到的北半球冬季气旋路径
DOI：
10.1002/qj.49712656311
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发表时间：
2000
影响因子：
8.9
通讯作者：
K. Fraedrich
中科院分区：
文献类型：
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作者：
Michaela Sickmöller;R. Blender;K. Fraedrich
1979-97 年欧洲中期天气预报中心重新分析了观测到的北半球冬季气旋活动 (DJF)。气旋轨迹是通过对 1000 hPa 位势高度场 (z1000) 中识别的最小值进行近邻搜索自动确定的。这些与传统的风暴路径进行了比较，传统的风暴路径由带通滤波的 500 hPa 位势高度异常的均方根定义。该分析涵盖北大西洋和北太平洋盆地。气旋密度（分布）的变化趋势与北大西洋的风暴路径相似，但在北太平洋则相反。在大西洋，由于区域气候压力向北移动，中心z1000低的气旋总数增加，而大梯度气旋的数量减少。在太平洋，梯度大（低）的强（弱）气旋数量增加（减少）。
The observed cyclone activity in the northern‐hemisphere winter (DJF) is investigated in 1979‐97 European Centre for Medium‐Range Weather Forecasts re‐analyses. The cyclone trajectories are determined automatically by a next‐neighbour search of minima identified in the 1000 hPa geopotential‐height field (z1000). These are compared with the traditional storm track, defined by the root mean square of the band‐pass filtered 500 hPa geopotential‐height anomaly. The analysis covers the North Atlantic and North Pacific basins. The trend of the cyclone density (distribution) is similar to that of the storm track in the North Atlantic, but opposite in the North Pacific. In the Atlantic, the total number of cyclones with low central z1000 increases, due to the northward shift towards lower regional climatological pressure, whereas the number of cyclones with large gradients decreases. In the Pacific, the number of intense (weak) cyclones with large (low) gradients increases (decreases).