Statistical downscaling of global climate projections over Tabuk city, northwest of Saudi Arabia.

Recent and future climate diagrams (surface air temperature, surface relative humidity, surface wind, and mean sea level pressure) over Tabuk are analyzed based on hourly observations (2016–2020) and hourly ERA5 datasets (1979–2020) with daily GFDL mini-ensemble mean (2006–2100). Moreover, the GFDL mini-ensemble mean is calculated based on the results of three different GFDL simulations (GFDL-CM3, GFDL-ESM2M, and GFDL-ESM2G). The data observed is used to describe the short-term current weather variabilities. However, ERA5 datasets are used to study the long-term current weather variabilities after bias removal by comparing them with the observations. Finally, a bias correction statistical model was developed by matching cumulative distribution functions (CDF) of corrected ERA5 and the mini-ensemble mean over 15 years (2006–2020). The obtained local statistic will be used to statically downscale the GFDL mini-ensemble means to study the future projection of the atmospheric parameters studied. The results show the efficiency of using ERA5 to describe Tabuk’s weather. This data for Tabuk, 1979–2020, displays a significant positive trend for surface air temperature (0.51 °C decade ^{̶ 1}), surface wind speed (0.02 m s ^{̶ 1} decade ^{̶ 1}), together with a significant negative trend for relative humidity (−0.38% decade ^̶1) and sea level pressure (−0.05 hPa decade ^{̶ 1}). The GFDL mini-ensemble mean projection, up to 2100, has a significant bias with the studied weather parameters. This is partly due to GFDL coarse resolution (2° × 2°). After removing the bias, the statistically downscaled simulations from the GFDL mini-ensemble mean to show that Tabuk’s climate will experience significant changes with a great range of uncertainties ranging from 0.34 to 2.28 °C century⁻¹, from −0.11 to −1.45% century⁻¹, from 0.016 to 0.073 m s⁻¹ century⁻¹, and from 0.08 to 0.57 hPa century⁻¹ according to the scenario used. [ABSTRACT FROM AUTHOR]