How skilful are Nowcasting Satellite Applications Facility products for tropical Africa?
How skilful are Nowcasting Satellite Applications Facility products for tropical Africa?
复制标题
临近预报卫星应用设施产品在热带非洲的性能如何？
DOI：
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发表时间：
2020
影响因子：
2.7
通讯作者：
J. Groves
中科院分区：
文献类型：
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作者：
P. Hill;T. Stein;A. Roberts;J. Fletcher;J. Marsham;J. Groves
在热带非洲，人口增长和气候变化正使越来越多的人面临天气灾害，卫星临近预报可能为缓解恶劣天气风险提供了一个至关重要的机会。数值天气预报在非洲大部分地区显示出有限的能力，气象雷达也很少见。然而，对地静止卫星提供了极好的空间和时间覆盖，通常持续时间较长的对流风暴会带来大雨、闪电和强风，这为卫星临近预报提供了宝贵的机会。在这里，我们评估了热带非洲卫星临近预报产品的技能：这些产品是常规生成的，但据我们所知，在全球挑战研究基金非洲气象信息和预报技术科学项目之前，热带非洲从未常规使用过这些产品。我们特别关注对流降雨率（CRR）和快速发展的雷暴对流预警（RDT‐CW）产品，证明两者都是有用的临近预报工具。CRR产品在热带非洲产生了非常不同的昼夜降雨气候。这与白天产品的更高技能有关，特别是在较大的降雨率下。RDT‐CW产品能够识别大约60%的强降雨（bbb50 - 5 mm·hr - 1）事件，并且随着降雨率的增加，检测到的比例也在增加。对于这两种产品，及时外推（分别为90分钟和60分钟）在热带非洲保持了有用的技能，激励工作开发更长的提前期预报。我们的结论是，卫星临近预报的广泛应用可以为非洲热带大部分地区提供新的、技术娴熟的短时间尺度天气预报。
Satellite nowcasting potentially provides a vital opportunity to mitigate against the risks of severe weather in tropical Africa, where population growth and climate change are exposing an ever growing number of people to weather hazards. Numerical weather prediction demonstrates limited skill for much of Africa and weather radars are rare. However, geostationary satellites provide excellent spatial and temporal coverage of the often long‐lasting convective storms that deliver heavy rain, lightning and strong winds, presenting a valuable opportunity for satellite nowcasting. Here, we evaluate the skill of satellite nowcasting products for tropical Africa: these products are routinely generated, but to our best knowledge never routinely used in tropical Africa before the Global Challenges Research Fund African SWIFT (Science for Weather Information and Forecasting Techniques) project. Focusing in particular on convective rainfall rate (CRR) and rapidly developing thunderstorm convection warning (RDT‐CW) products, we demonstrate that both are useful nowcasting tools. The CRR product produces very different rainfall climatologies for day and night in tropical Africa. This is associated with greater skill of the product during daytime, particularly for heavier rain rates. The RDT‐CW product is able to identify around 60% of heavy (>5 mm·hr−1) rainfall events with the fraction detected increasing with increasing rainfall rate. For both products, extrapolation forwards in time (up to 90 and 60 min, respectively) maintains useful skill in tropical Africa, motivating work to develop longer lead‐time nowcasts. We conclude that widespread uptake of satellite nowcasting could provide new skilful weather predictions on short time‐scales in much of tropical Africa.
影响因子：
3.2
作者：
Woodhams, Beth J.;Birch, Cathryn E.;Boyd, Douglas F. A.
通讯作者：
Boyd, Douglas F. A.