Impact of ENSO on East African ecosystems: a multivariate analysis based on climate and remote sensing data
Impact of ENSO on East African ecosystems: a multivariate analysis based on climate and remote sensing data
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DOI：
10.1046/j.1365-2699.2000.00208.x
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发表时间：
2000-11-01
影响因子：
6.4
通讯作者：
Lambin, EF
中科院分区：
文献类型：
--
作者：
Plisnier, PD;Serneels, S;Lambin, EF
1厄尔尼诺-南方涛动（ENSO）是热带地区气候和生态系统生产力年际变化的重要驱动因素。以前的大多数研究都是根据降雨量等单一变量分析厄尔尼诺/南方涛动引起的气候变化。2本研究的目的是通过以空间上明确的方式和在不同的时间滞后内测量厄尔尼诺/南方涛动指数与若干生态系统变量之间的遥相关，增进对厄尔尼诺/南方涛动对东非生态系统影响的了解。我们将气象站测得的气候变量的时间序列与遥感测得的植被指数和地表温度数据的时间序列相结合，分析了该区域遥相关的空间格局。然而，遥相关的模式比一般假设的要复杂得多，无论是在空间分布方面还是对不同生态系统变量的影响方面。并非所有的气候和陆面变量都以相同的方式与ENSO遥相关，这导致ENSO对生态系统的影响复杂。此外，厄尔尼诺/南方涛动的影响在空间上差别很大，因为这种影响的方向、程度和时间受到当地气候系统、是否有大湖、是否靠近海岸以及可能受到当地地形和土地覆盖的控制。
1 The El Nino-Southern Oscillation (ENSO) is an important driver of inter-annual variations in climate and ecosystem productivity in tropical regions. Most previous studies have analysed ENSO-induced changes in climate based on a single variable, such as rainfall. Also, it is generally assumed that the ENSO impact in East Africa is geographically uniform.2 The objective of this study is to improve understanding of the impact of ENSO on East African ecosystems, by measuring teleconnections between an ENSO index and a number of ecosystem variables in a spatially explicit way and for different time lags. We analysed the spatial patterns of teleconnections in the region by combining time series of climate variables measured for meteorological stations with time series of a vegetation index and surface temperature data measured by remote sensing.3 Our results confirm the ENSO impact on the climatic and ecological variability in East Africa. However, the pattern of teleconnections is much more complex than generally assumed, both in terms of spatial distribution and impact on different ecosystem variables. Not all climate and land surface variables are teleconnected to ENSO in the same way, which leads to a complex impact of ENSO on the ecosystem. Moreover, the ENSO impact is highly differentiated in space, as the direction, magnitude and timing of this impact are controlled by the local climate system, the presence of large lakes, proximity to the coast and, possibly, local topography and land cover.