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

绝热过程对中纬度天气系统的演化和强度有强烈的影响。这些过程与由于水的相变、表面通量或辐射效应而产生的潜热释放有关，并且它们强烈依赖于经常发生在狭窄气流中的水蒸气的输送。很难从标准气象资料中定量地评估这些过程。因此，本项目将(1)利用YOTC项目的新数据集、以往野外试验的湿度观测数据和数值模式技术，更好地诊断和量化这些过程对不同中纬度天气系统（包括气旋、阻塞和急流）演变的作用。研究这些系统的预报精度并进行高分辨率模式敏感性实验将(2)评估非绝热过程与预测高影响天气事件质量的相关性，并有助于查明这些过程在NWP模式中表示的潜在缺陷。(1)和(2)的结果将为虚拟现场实验(3)提供基础，该实验将测试计划中的国际现场实验T-NAWDEX的飞行策略设计。在本实验中，将在关键地区观测绝热过程，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.