Climate variability of the Indian Ocean and malaria resurgence in the east African highlands

厄尔尼诺-南方涛动（ENSO）与1990年代东非高地的疟疾流行有关。我们发现，印度洋偶极子（IOD），耦合的海洋-大气相互作用与印度洋的温度变化，影响高原疟疾重新出现。使用交叉小波相干分析，我们发现疟疾的时间序列和偶极子模式指数（偶极子），一个指标的东西温度梯度在整个热带印度洋，在20世纪90年代在三个高原地区之间的四年长的相干周期。相反，我们发现在低地地区疟疾和疟疾之间的一致性不那么明显。高地和低地站点之间的差异可能反映了维多利亚湖对其气候盆地产生的中尺度系统的影响，并表明当地气候对强IOD的敏感性。

The El-Nino-Southern Oscillation (ENSO) has been connected to malaria epidemics in the 1990s in the east African highlands. We show that the Indian Ocean Dipole (IOD), a coupled ocean-atmosphere interaction related to temperature changes in the Indian Ocean, affected highland malaria re-emergence. Using cross-wavelet coherence analysis, we found four-year long coherent cycles between the malaria time series and the dipole mode index (DMI), an indicator of the east-west temperature gradient across the tropical Indian Ocean, in the 1990s in three highland localities. Conversely, we found a less pronounced coherence between malaria and DMI in lowland localities. The differences between highland and lowland sites may reflect the effects of mesoscale systems generated by Lake Victoria on its climate basin and indicate the sensitivity of the local climate to a strong IOD.