The effect of horizontal resolution on Indian monsoon depressions in the Met Office NWP model
The effect of horizontal resolution on Indian monsoon depressions in the Met Office NWP model
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英国气象局 NWP 模型中水平分辨率对印度季风洼地的影响
DOI：
10.1002/qj.3030
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发表时间：
2017
影响因子：
8.9
通讯作者：
A. Turner
中科院分区：
文献类型：
--
作者：
Kieran M. R. Hunt;A. Turner
季风低压是天气尺度特征，在夏季季风季节期间，印度北方的降雨量占很大比例，因此在数值天气预报（NWP）模式中量化其结构和行为非常重要。众所周知，增加模式分辨率与短期内改善预报和长期全球环流以及更好地代表热带气旋密切相关;在这里，我们使用气象局统一模式探索低气压对分辨率变化的敏感性。2013年至2015年的7个低气压数值预报案例研究在8个分辨率下运行，对应于赤道网格间距在16至208 km之间，并与热带降雨测量使命（TRMM）和ERA-中期再分析的相同事件的数据进行比较。我们发现，在频谱的低分辨率端，分辨率的增加导致复合结构的改善，但回报递减;也就是说，预测轨迹和结构的改善变得更小。该模型还持续高估了低气压的强度，特别是风速和高空暖核，来源似乎起源于对流层中部。的日周期分辨率的敏感性也进行了探讨：层状组件被发现是非常好的代表模型，而对流组件描述得很差。随着模式分辨率的增加，结构的大多数组件的改善分别在N320（63公里）和N512（39公里）以外的动力和热力学领域是边际的。
Monsoon depressions are synoptic‐scale features that are responsible for a significant fraction of the rain over northern India during the summer monsoon season, and therefore it is important to quantify their structure and behaviour in numerical weather prediction (NWP) models. It is known that increasing model resolution is strongly correlated with improved forecasts in the short term and global circulation in the longer term, as well as better representation of tropical cyclones; here, we explore the sensitivity of depressions to changes in resolution using the Met Office Unified Model. Seven NWP case‐studies of depressions from 2013 to 2015 were run at eight resolutions corresponding to equatorial grid spacing of between 16 and 208 km, and compared with data for the same events from Tropical Rainfall Measuring Mission (TRMM) and ERA‐Interim reanalysis. We found that, at the low‐resolution end of the spectrum, increases in resolution led to improvements in the composite structure, but with diminishing returns; that is to say, the improvements in forecast track and structure become smaller. The model also persistently overestimated the depression intensity, in particular the wind speed and the warm core aloft–with the source appearing to originate in the mid‐troposphere. The sensitivity of the diurnal cycle to resolution was also explored: the stratiform component was found to be very well represented by the model, whereas the convective component was described quite poorly. Improvement in most components of structure with increasing model resolution were marginal beyond N320 (63 km) and N512 (39 km) for dynamic and thermodynamic fields respectively.
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影响因子：
8.9
作者：
Hunt, Kieran M. R.;Parker, Douglas J.
通讯作者：
Parker, Douglas J.
DOI：
10.5194/gmd-2016-194-supplement
发表时间：
2017
期刊：
--
影响因子：
--
作者：
D. Walters;I. Boutle;M. Brooks;T. Melvin;R. Stratton;S. Vosper;H. Wells;K. Williams;N. Wood
通讯作者：
D. Walters;I. Boutle;M. Brooks;T. Melvin;R. Stratton;S. Vosper;H. Wells;K. Williams;N. Wood
VOCALS-REx 期间气象局预报模型中的层积云预测评估
影响因子：
6.3
作者：
Abel S
通讯作者：
Abel S
影响因子：
4.6
作者：
Johnson, Stephanie J.;Levine, Richard C.;Strachan, Jane
通讯作者：
Strachan, Jane