Can the Frequency of Blocking Be Described by a Red Noise Process?
Can the Frequency of Blocking Be Described by a Red Noise Process?
复制标题
阻塞频率可以用红噪声过程来描述吗？
DOI：
10.1175/2008jas2907.1
复制
发表时间：
2009
影响因子：
3.1
通讯作者：
Woollings T
中科院分区：
文献类型：
--
作者：
Woollings T
The frequency of persistent atmospheric blocking events in the 40-yr ECMWF Re-Analysis (ERA-40) is compared with the blocking frequency produced by a simple first-order Markov model designed to predict the time evolution of a blocking index [defined by the meridional contrast of potential temperature on the 2-PVU surface (1 PVU ≡ 1 × 10−6K m2kg−1s−1)]. With the observed spatial coherence built into the model, it is able to reproduce the main regions of blocking occurrence and the frequencies of sector blocking very well. This underlines the importance of the climatological background flow in determining the locations of high blocking occurrence as being the regions where the mean midlatitude meridional potential vorticity (PV) gradient is weak. However, when only persistent blocking episodes are considered, the model is unable to simulate the observed frequencies. It is proposed that this persistence beyond that given by a red noise model is due to the self-sustaining nature of the blocking phenomenon.
