Quantifying the role of diabatic processes for forecast errors associated with mid-latitude weather systems - A combined observational, diagnostic and modelling approach (DIAP)

非绝热过程可以强烈地影响中纬度天气系统的演变和强度。这些过程与水的相变、地表通量或辐射效应引起的潜热释放有关，它们强烈依赖于狭窄气流中经常发生的水蒸气的传输。根据标准气象数据很难对这些过程进行定量评估。因此，该项目将(1)使用来自YOTC项目的新数据集、以前野外实验的湿度观测和数值模式技术来更好地诊断和量化这些过程对不同中纬度天气系统的演变的作用，包括气旋、阻塞和急流。研究这些系统的预报精度和进行高分辨率模式敏感性试验将(2)评估非绝热过程与预报高影响天气事件的质量的相关性，并有助于查明在NWP模式中表示这些过程的潜在缺陷。(1)和(2)的结果将为虚拟实地试验(3)提供基础，该试验将检验计划中的国际实地试验T-NAWDEX的飞行战略设计。在这次试验中，将在关键地区观测非绝热过程，以改进北大西洋/欧洲天气系统的预报。

Diabatic processes can strongly influence the evolution and intensity of mid-latitude weather systems. These processes are associated with latent heat release due to phase transitions of water, surface fluxes, or radiative effects, and they strongly depend on the transport of water vapour that often occurs in narrow airstreams. It is difficult to quantitatively assess these processes from standard meteorological data. Therefore, this project will (1) use novel datasets from the YOTC project, humidity observations from previous field experiments, and numerical model techniques to better diagnose and quantify the role of theses processes for the evolution of different mid-latitude weather systems, including cyclones, blockings, and jet streams. Investigating the forecast accuracy of these systems and performing high-resolution model sensitivity experiments will (2) assess the relevance of diabatic processes for the quality of predicting high-impact weather events and help pinpointing potential shortcomings in the representation of these processes in NWP models. Results from (1 and 2) will provide the basis for a virtual field experiment (3) that will test the design of flight strategies for the planned international field experiment T-NAWDEX. Within this experiment, diabatic processes will be observed in key areas for improving the prediction of North Atlantic / European weather systems.