The 2010-2011 drought in the Horn of Africa in ECMWF reanalysis and seasonal forecast products
The 2010-2011 drought in the Horn of Africa in ECMWF reanalysis and seasonal forecast products
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DOI：
10.1002/joc.3545
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发表时间：
2013-06-01
期刊：
影响因子：
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通讯作者：
Pappenberger, Florian
中科院分区：
文献类型：
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作者：
Dutra, Emanuel;Magnusson, Linus;Pappenberger, Florian
本研究评估了欧洲中期天气预报中心（ECMWF）产品在2010-2011年非洲之角（HoA）干旱期间监测和预报干旱情况的使用情况。该区域在2010年3月至12月和2011年3月至5月的雨季都受到降水不足的影响。这些异常被捕获的ERA中期再分析（ERAI），尽管它的局限性，代表3月至5月的年际变化。ERAI的土壤湿度异常也确定了2010年10月初干旱状况的开始，2011年9月持续干旱仍然存在。这一信号在归一化植被指数遥感数据中也很明显。2010年10月至12月的降水不足与强拉尼娜事件有关。ECMWF对2010年12月至12月的季节性预报预测了2010年6月以后的拉尼娜事件。预报还预测，从2010年7月起，12月至12月的降雨量将低于平均水平。随后的3月至5月降雨量异常仅由ECWMF新的季节预报系统在2011年3月开始的预报中捕获。我们的分析表明，最近（自1999年以来）在该地区的干燥在3月至5月的季节被捕获的新ECMWF季节预报系统，并与最近公布的结果是一致的。HoA地区及其人口极易受到未来干旱的影响，因此，全球干旱监测和预测，如本文所述，将在未来变得越来越重要。版权所有（c）2012皇家气象学会
This study evaluates the use of European Centre for Medium-Range Weather Forecasts (ECMWF) products in monitoring and forecasting drought conditions during the recent 2010-2011 drought in the Horn of Africa (HoA). The region was affected by a precipitation deficit in both the October-December 2010 and March-May 2011 rainy seasons. These anomalies were captured by the ERA-Interim reanalysis (ERAI), despite its limitations in representing the March-May interannual variability. Soil moisture anomalies of ERAI also identified the onset of the drought condition early in October 2010 with a persistent drought still present in September 2011. This signal was also evident in normalized difference vegetation index (NDVI) remote sensing data. The precipitation deficit in October-December 2010 was associated with a strong La Nina event. The ECMWF seasonal forecasts for the October-December 2010 season predicted the La Nina event from June 2010 onwards. The forecasts also predicted a below-average October-December rainfall, from July 2010 onwards. The subsequent March-May rainfall anomaly was only captured by the new ECWMF seasonal forecast system in the forecasts starting in March 2011. Our analysis shows that a recent (since 1999) drying in the region during the March-May season is captured by the new ECMWF seasonal forecast system and is consistent with recently published results. The HoA region and its population are highly vulnerable to future droughts, thus global monitoring and forecasting of drought, such as that presented here, will become increasingly important in the future. Copyright (c) 2012 Royal Meteorological Society