Strengthening of Tropical Indian Ocean Teleconnection to the Northwest Pacific since the Mid-1970s: An Atmospheric GCM Study
Strengthening of Tropical Indian Ocean Teleconnection to the Northwest Pacific since the Mid-1970s: An Atmospheric GCM Study
复制标题
自 20 世纪 70 年代中期以来热带印度洋与西北太平洋遥相关的加强：一项大气 GCM 研究
DOI：
10.1175/2010jcli3577.1
复制
发表时间：
2010-10-01
影响因子：
4.9
通讯作者：
Xie, Shang-Ping
中科院分区：
文献类型：
--
作者：
Huang, Gang;Hu, Kaiming;Xie, Shang-Ping
夏季西北太平洋气候异常与前冬厄尔尼诺-南方涛动（ENSO）的相关性在20世纪70年代中期加强并保持较高水平。本研究调查的假设，热带印度洋（TIO）响应ENSO是关键的年代际变化，使用21个成员的集合模拟与社区大气模式，版本3（CAM3）强迫观测历史的海表温度（SST）为1950 - 2000年。在模式后报中，TIO对夏季西北太平洋的影响在20世纪70年代中期加强，TIO遥相关的加强与夏季TIO上SST变率的加强相一致。这一结果被模式在模拟20世纪70年代极移后夏季西北太平洋气候异常增加的技能所证实。厄尔尼诺-在20世纪70年代极移之前，TIO引起的变暖迅速衰减，但在之后的夏季，TIO引起的变暖持续增长，这种TIO变暖演变的差异决定了TIO的强度在随后的夏季与西北太平洋的遥相关。一个反对称的风模式，在整个赤道TIO的春季发展，和相关的东北风异常的援助，夏季变暖的北印度洋，反对盛行的西南季风。在模式中，这种反对称的春季风型在20世纪70年代的转变之后发展得很好，但在此之前并不存在。
The correlation of northwest (NW) Pacific climate anomalies during summer with El Nino-Southern Oscillation (ENSO) in the preceding winter strengthens in the mid-1970s and remains high. This study investigates the hypothesis that the tropical Indian Ocean (TIO) response to ENSO is key to this interdecadal change, using a 21-member ensemble simulation with the Community Atmosphere Model, version 3 (CAM3) forced by the observed history of sea surface temperature (SST) for 1950-2000. In the model hindcast, the TIO influence on the summer NW Pacific strengthens in the mid-1970s, and the strengthened TIO teleconnection coincides with an intensification of summer SST variability over the TIO. This result is corroborated by the fact the model's skills in simulating NW Pacific climate anomalies during summer increase after the 1970s shift.During late spring to early summer, El Nino-induced TIO warming decays rapidly for the epoch prior to the 1970s shift but grows and persists through summer for the epoch occurring after it. This difference in the evolution of the TIO warming determines the strength of the TIO teleconnection to the NW Pacific in the subsequent summer. An antisymmetric wind pattern develops in spring across the equator over the TIO, and the associated northeasterly anomalies aid the summer warming over the north Indian Ocean by opposing the prevailing southwest monsoon. In the model, this antisymmetric spring wind pattern is well developed after but absent before the 1970s shift.