Naslov
WRF-ARW simulations of shallow and deep bora flows at the Dubrovnik airport, Croatia

Autori
Večenaj, Željko ; Telišman Prtenjak, Maja ; Grisogono, Branko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
35th International Conference on Alpine Meteorology 2019

Mjesto i datum
Riva del Garda, Italija, 02.09.2019. - 06.09.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Bora flows ; WRF-ARW model

Sažetak
One of the main characteristics of bora flows at the Dubrovnik airport (LDDU) is the difference between the so-called shallow or standard bora model (hereafter the SM-bora) and the so-called deep bora model (hereafter the N-bora). SM-bora occurs when bora blows in lower troposphere and the height of the layer within which the airflow is contained can be clearly determined. N-bora is characterized by the northern airflow throughout the whole troposphere and there is no clear boundary of the airflow layer. It is previously showed that main differences between these two bora types are significantly larger mean wind speed and smaller variations of mean wind speed and wind direction in SM-bora than in N-bora. Despite having lower mean wind speed, gusts in N-bora are comparable with those in SM-bora. Because of these characteristics, N-bora is much more difficult to predict and much more hazardous for the air traffic. In this work for the modeling of mesoscale conditions during case studies of SM- and N-bora flows, the mesoscale meteorological model Weather Research and Forecasting-Advanced Research (WRF-ARW) has been used. Orographic data comes from 90 m resolution from the Shuttle Radar Topographic Mission digital topographic database. NCEP data is used to determine the initial and boundary conditions. The initial and boundary conditions are downloaded from the GFS analysis. The largest domain includes the Apennine Peninsula, the western part of the Balkan Peninsula and the Alps with a 13.5 km grid spacing. Other nested domains have less spatial grid spacing of 4.5 km, 1.5 km and finest domain with 500 m. We simulated N-bora event that lasted from 21 January 2018 a 12 UTC until 24 January 2018 at 00 UTC and SM-bora event that lasted from 20 March 2018 at 12 to 23 March 2018 at 00 UTC. Comparison of these simulations with the ultrasonic anemometer measurements indicate that the WRF-ARW model can simulate mean wind speed and turbulence kinetic energy for both bora types at LDDU quite successfully.

Izvorni jezik
Engleski

Znanstvena područja
Geofizika

POVEZANOST RADA