The impact of time‐varying sea surface temperature on UK regional atmosphere forecasts,Meteorological Applications

当前位置： X-MOL 学术 › Meteorol. Appl. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

The impact of time‐varying sea surface temperature on UK regional atmosphere forecasts
Meteorological Applications ( IF 2.3 ) Pub Date : 2021-03-24 , DOI: 10.1002/met.1983
Sana Mahmood ₁ , Huw Lewis ₁ , Alex Arnold ₁ , Juan Castillo ₁ , Claudio Sanchez ₁ , Chris Harris ₂

Affiliation

A new approach to improve the ocean surface boundary condition used in regional numerical weather prediction is proposed. Typically, regional atmosphere forecast systems assume a fixed sea surface temperature during a simulation. The study assesses the use of ocean temperature from an operational regional ocean model as an evolving lower boundary in a kilometre‐scale regional atmosphere configuration centred on the UK. Simulations of a winter and two five day duration summer case studies associated with anomalously warm temperatures are considered. The largest impact is found in summer, when a growing cold bias in mean temperature over land compared with observations is apparent when using a fixed global‐scale analysis lower boundary condition. The mean error is improved by 0.1 K when using a fixed temperature boundary condition from a kilometre‐scale regional ocean model initial condition. When using hourly surface temperature data from the same regional ocean model, the error is improved by 0.5 K for this case. Prediction of daytime maximum air temperature is also improved during the summer heat wave cases. A winter case study shows marginal improvement over the ocean and negligible changes over land. These results are confirmed in longer duration experiments using an hourly cycling regional forecast system with data assimilation for summer and winter periods. A systematic and statistically significant improvement of near‐surface temperature verification relative to the observations over land is demonstrated for both summer and winter using the new approach. This study supports future operational implementation of a time‐varying lower boundary for regional numerical weather prediction.

中文翻译：

海面温度随时间变化对英国区域大气预报的影响

提出了一种改善区域数值天气预报中海洋表面边界条件的新方法。通常，区域大气预报系统在模拟过程中会假设海面温度固定。这项研究评估了以英国为中心的一公里规模的区域大气构造中运行的区域海洋模型作为不断演变的下边界的海洋温度的使用。考虑了与异常温暖的温度相关的冬季和两个持续五天的夏季案例研究的模拟。在夏季，当使用固定的全球规模下限边界条件进行观测时，与观测值相比，陆地平均温度的冷偏差越来越明显，这是最大的影响。平均误差提高了0。当使用千米级区域海洋模型初始条件中的固定温度边界条件时为1K。使用来自相同区域海洋模型的每小时地表温度数据时，在这种情况下，误差提高了0.5K。在夏季热浪期间，白天最高气温的预测也得到了改善。一项冬季案例研究表明，海洋略有改善，陆地变化可忽略不计。这些结果在较长时间的实验中得到了证实，该实验使用了每小时循环的区域预测系统，并具有夏，冬季的数据同化功能。使用该新方法，相对于陆地上的观测值，已证明在夏季和冬季，系统地和统计上的显着提高。

更新日期：2021-03-25

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11