Evaluation of the Performance of the WRF Model in a Hyper-Arid Environment: A Sensitivity Study

Abstract

Accurate simulation of boundary layer surface meteorological parameters is essential to achieve good forecasting of weather and atmospheric dispersion. This paper is devoted to a model sensitivity study over a coastal hyper-arid region in the western desert of the United Arab Emirates. This region hosts the Barakah Nuclear Power Plant (BNPP), making it vital to correctly simulate local weather conditions for emergency response in case of an accidental release. We conducted a series of high-resolution WRF model simulations using different combinations of physical schemes for the months January 2019 and June 2019. The simulated results were verified against in-situ meteorological surface measurements available offshore, nearshore, and inland at 12 stations. Several statistical metrics were calculated to rank the performance of the different simulations and a near-to-optimal set of physics options that enhance the performance of a WRF model over different locations in this region has been selected. Additionally, we found that the WRF model performed better in inland locations compared to offshore or nearshore locations, suggesting the important role of dynamical SSTs in mesoscale models. Moreover, morning periods were better simulated than evening ones. The impact of nudging towards station observations resulted in an overall reduction in model errors by 5–15%, which was more marked at offshore and nearshore locations. The sensitivity to grid cell resolution indicated that a spatial resolution of 1 km led to better performance compared to coarser spatial resolutions, highlighting the advantage of high-resolution simulations in which the mesoscale coastal circulation is better resolved.

Evaluation of the WRF-Chem Performance for gaseous pollutants over the United Arab Emirates

“…The lower correlation observed in marine regions possibly arises from the more muted diurnal cycle (Fig.2) and the model's inability to properly represent the complex land-sea mask even at 3 km spatial resolution. Similar results were reported inAbida et al, (2022), where the WRF model demonstrates improved accuracy in inland areas compared to offshore or coastalregions. The RMSE (MAE) values stand at 3.57 °C (2.68 °C) for land and 1.67 °C (1.47 °C) for marine regions, respectively.…”

“…During the daytime, there is a tendency for the model to exhibit a warm bias, while at night and evening, a cold bias is more apparent. Such discrepancies in temperature have been reported before (Abida et al, 2022;Branch et al, 2021;Fonseca et al, 2021;Schwitalla et al, 2020;Temimi et al, 2020a). Overall, the WRF-Chem model displays a consistent cold bias of less than 0.5 °C for both environments during the summer months.…”

“…In the month of June, the model Overall, the model tends to overestimate WS10m and SR across both seasons, while it underestimates the T2m in winter and overestimates it in summer. Such variable performance of the model has been noted in findings from prior research (for example, Schwitalla et al, 2020;Wehba et al, 2017;Fonseca et al, 2020;Abida et al, 2022). Furthermore, a more detailed analysis of the biases identified in T2m and WS10m, including an examination of the diurnal variation of these parameters, is presented in the following sections.…”

“…This discrepancy is linked to alterations in wind direction driven by land and sea breeze circulations. Consequently, numerous studies have previously emphasized the model's tendency for wind speed overprediction (Abida et al, 2022;Branch et al, 2021;Fonseca et al, 2021;Schwitalla et al, 2020;Temimi et al, 2020a).…”

The Wind‐Blown Sand Experiment in the Empty Quarter Desert: Roughness Length and Saltation Characteristics

“…This observation is expected, as the SHAMS location is further inland compared to other coastal locations, such as Barakah and Abu Dhabi. Previous studies conducted at Barakah reported the persistent occurrence of strong northwesterly winds for several days when the location is under the influence of favorable synoptic conditions (Abida et al, 2022;Nelli et al, 2022;Weston et al, 2022).…”