Influence of the Details of Topography on Weather Forecast – Evaluation of HARMONIE Experiments in the Sochi Olympics Domain over the Caucasian Mountains

Frontiers in Digital Humanities

, Sami¹  Rontu, Laura¹  Wastl, Clemens²  Niemelä³ 

[1] Finnish Meteorological Institute, Helsinki, Finland;Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria

关键词: Orographic effects;    radiation flux;    Numerical Weather Prediction;    parametrization;    FROST-2014;    Winter Olympics;   

DOI  :  10.3389/feart.2016.00013

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

New fine-resolution surface elevation data was implemented into HARMONIE-AROME-SURFEX Numerical Weather Prediction (NWP) system. The grid-scale mean orography, used as a basis of the model's terrain-following vertical coordinate, as well as variables for suggested new parametrizations of radiation and momentum fluxes were derived. Validation against the surface observations from the Sochi Winter Olympic Games 2014, provided by the WMO FROST-2014 program at the Caucasian mountains, showed minor degradation of the of then screen-level temperature forecast when only the source orography was updated. Implementation of the orographic radiation parametrizations allowed to alleviate the degradation of scores. Detailed sensitivity studies, done by using three-dimensional and single-column experiments, showed that substantial and physically realistic changes in the downwelling short- and longwave radiation fluxes took place locally. However, their influence on the the simulated screen-level temperature remained small. Comparison of the simulated and observed radiation fluxes would offer a reliable alternative for validation of NWP models. Unfortunately, surface-level radiation observations were not made during the Sochi Olympics.

【 授权许可】

CC BY