论文部分内容阅读
The winter extratropical cyclone activity on the Southern Hemisphere during the last one thousand years within a global climate simulation was analysed by tracking algorithm,and then clustering them consecutively for each hundred yaers.There are very strong year-to-year variability for Southern Hemispheric winter extratropical cyclone numbers and larger variations on centennial time scale than Northern Hemispherical counterparts.Howerer,no obvious trend can be found.The mean tracks of clusters over Southern Indian Ocean and near New Zealand shift northward between the 11th and 20th century while the clusters in the middle Southern Pacific shift southward.Storm track clusters with largest deepening rates are found over the western Southern Indian Ocean.