عنوان مقاله [English]
In this work, sensitivity and performance of the Weather Research and Forecasting (WRF) model for surface wind field simulations are evaluated under several initial and boundary conditions, along with, different planetary boundary layer (PBL) schemes during several dates over the Persian Gulf region. Since there are differences between production approaches and development periods of analysis and reanalysis data (namely, assimilation system) on the one hand, and differences in method applied for PBL parameterization by any scheme on the other hand, this paper aims to identify a suitable set up among the whole configurations which are under examination. To this end, three datasets (two reanalyses and one analysis) including, ERA-Interim, NCEP-R2, and NCEP-FNL and six PBL schemes (two local and four nonlocal) including ACM2, BouLac, MYJ, MYNN, QNSE, and YSU accompanied by their relevant surface-layer schemes are used. To assess the WRF model wind simulations available observational wind data including 22 synoptic weather stations located in the region and QuikSCAT and ASCAT satellites observations are employed.
Findings of this study indicate when the wind simulations are compared with synoptic weather stations observations, irrespective of the type of PBL scheme, ERA-Interim and NCEP-FNL datasets exhibit better performance in comparison with the NCEP-R2. In addition, when PBL schemes are also considered, results show that the combination of YSU scheme and ERA-Interim reanalysis data leads to a better estimate of wind speed and combination of YSU and NCEP-FNL data generates less error for wind direction. Moreover, comparison of model wind simulations and observations of QuikSCAT and ASCAT satellites show that there are no substantial differences between various configurations. However, using YSU and ACM2 scheme, WRF model generates speed and direction of the wind close to observations of QuikSCAT. All the tests have almost similar results wi0th respect to ASCAT satellite, nevertheless YSU scheme estimate slightly better than that of other schemes.
The overall results exhibited from this study revealed that the major difference between WRF wind simulation and measured winds arises from the choice of initial conditions data compared to changing PBL scheme. Consequently, changing initial and boundary data has a noticeable impact on the model wind results and thus in future studies emphasize must be more on reanalysis and analysis datasets and the option of WRF PBL parameterization scheme will be the second priority.
Due to the fairly good similarity of the model surface wind with QuikSCAT and ASCAT, the choice of WRF model simulations as offshore wind database can be a valid available alternative instead of QuikSCAT and ASCAT wind, particularly when meeting their limitation in spatial resolution (swath data) or temporal sampling.