New insights into the rainfall variability in the tropical Andes on seasonal and interannual time scales
New insights into the rainfall variability in the tropical Andes on seasonal and interannual time scales
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关于热带安第斯山脉季节性和年际时间尺度降雨量变化的新见解
DOI：
10.1007/s00382-018-4590-8
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发表时间：
2019
期刊：
影响因子：
4.6
通讯作者：
T. Lebel
中科院分区：
文献类型：
--
作者：
H. Segura;C. Junquas;J. Espinoza;M. Vuille;Y. R. Jauregui;A. Rabatel;T. Condom;T. Lebel
在这项研究中，我们分析了热带安第斯山脉（$$20^{\circ }\hbox {S}$$ 20°S - $$1^{\circ }\hbox {N}$$ 1°N）在季节和年际时间尺度上与主要降雨模式相关的大气机制。使用均匀的高空间分辨率降水数据集（$$0.05^{\circ }\times 0.05^{\circ }$$ 0.05°×0.05°）按月时间步长(CHIRPS；1981-2016年)、206个雨量站的现场降水、功率谱和EOF分析，我们确定了三个具有特定季节和年际降雨模式特征的安第斯地区：赤道安第斯山脉（EA, $$5^{\circ }\hbox {S}$$ 5°S - $$1^{\circ }\hbox {N}$$ 1°N）、过渡区（TZ, $$8^{\circ }\hbox {S}$$ 8°S - $$5^{\circ }\hbox {S}$$ 5°S）和热带安第斯山脉南部（STA, $$20^{\circ }\hbox {S}$$ 20°S - $$8^{\circ }\hbox {S}$$ 8°S）。在季节时间尺度上，东亚和太平洋的主要降水模式为单峰模式，而TZ则为双峰模式。东亚和TZ在2 - 4月有相同的湿季，这与Walker Cell减弱、热带辐合带（ITCZ）的偏南位置以及来自赤道亚马逊河流域的强西向湿度输送有关。后一种机制和安第斯山脉海拔的降低与青藏高原10 - 11月的雨季有关。玻利维亚高压的存在和低空急流的向北延伸与12月至3月期间安第斯地区20 $$^{\circ }$$到8 $$^{\circ }$$°S之间的降水有关。在年际时间尺度上，STA （TZ）的极端月湿事件（EMWE）与12 - 3月（2 - 4月）亚马逊西部（赤道）的对流有关，显示了亚马逊和安第斯山脉之间的大气关系。在2 - 4月期间，东太平洋和TZ和EA的极端月干事件（EMDE）与Walker Cell的增强有关。此外，东太平洋东太平洋过渡带中EMWE （EMDE）与异常南移（北移）有关。此外，我们发现在2月至4月EMWE期间，$$10^{\circ }\hbox {S}$$ 10°S以北安第斯山脉高海拔地区的降水与200 hPa的东风之间存在关系。最后，EA （STA）的月极端事件与赤道西（中）太平洋海温异常有关。
In this study, we analyze the atmospheric mechanisms associated with the main rainfall patterns in the tropical Andes ($$20^{\circ }\hbox {S}$$20∘S–$$1^{\circ }\hbox {N}$$1∘N) on seasonal and interannual time scales. Using a homogeneous and high spatial resolution precipitation data set ($$0.05^{\circ }\times 0.05^{\circ }$$0.05∘×0.05∘) at monthly time step (CHIRPS; 1981–2016), in-situ precipitation from 206 rain-gauge stations, power spectrum and EOF analysis, we identify three Andean regions characterized by specific seasonal and interannual rainfall modes: the equatorial Andes (EA, $$5^{\circ }\hbox {S}$$5∘S–$$1^{\circ }\hbox {N}$$1∘N), the transition zone (TZ, $$8^{\circ }\hbox {S}$$8∘S–$$5^{\circ }\hbox {S}$$5∘S) and the southern tropical Andes (STA, $$20^{\circ }\hbox {S}$$20∘S–$$8^{\circ }\hbox {S}$$8∘S). On seasonal time scales, the main mode of precipitation in the EA and STA are characterized by a unimodal regime, while the TZ is represented by a bimodal regime. The EA and the TZ share the same wet season in the February–April period, which is associated with a weakened Walker Cell, the southerly position of the Intertropical Convergence Zone (ITCZ) and a strong westward humidity transport from the equatorial Amazon. This latter mechanism and a reduced elevation of the Andes are associated with the October–November wet season in the TZ. The presence of the Bolivian High and the northward extension of the Low Level Jet are associated with the precipitation over Andean regions between 20$$^{\circ }$$∘S and 8$$^{\circ }$$∘S in the December–March period. On interannual time scales, extreme monthly wet events (EMWE) in the STA (TZ) are related to convection over the western (equatorial) Amazon during the December–March (February–April) period, showing an atmospheric relationship between the Amazon and the Andes. Extreme monthly dry events (EMDE) in the TZ and in the EA during the February–April period are related to a strengthened Walker Cell, especially in the eastern Pacific. In addition, EMWE (EMDE) in the EA are associated with an anomalous southward (northward) displaced eastern Pacific ITCZ. Moreover, we find a relationship between precipitation at higher elevations in the Andes north of $$10^{\circ }\hbox {S}$$10∘S and easterly winds at 200 hPa during February–April EMWE. Finally, extreme monthly events in the EA (STA) are related to sea surface temperature anomalies in the western (central) equatorial Pacific.
厄瓜多尔南部安第斯盆地中尺度对流系统的气候学和遥相关：以帕特盆地为例
影响因子：
2.9
作者：
Campozano;K. Trachte;R. Celleri;E. Samaniego;J. Bendix;C. Albuja ;J. Mejia
通讯作者：
J. Mejia
安第斯山脉的降雨和云动态：厄瓜多尔南部案例研究
影响因子：
2.9
作者：
Campozano;R. Celleri;K. Trachte;J. Bendix ;E Samaniego
通讯作者：
E Samaniego
影响因子：
4.9
作者：
S. Xie;Qihua Peng;Y. Kamae;Xiao‐Tong Zheng;H. Tokinaga;Dongxiao Wang
通讯作者：
S. Xie;Qihua Peng;Y. Kamae;Xiao‐Tong Zheng;H. Tokinaga;Dongxiao Wang