Influence of Direct-Downscaling and One-Way Nesting on Daily Mean Air Temperature of Egypt Using the RegCM4

Anwar, Samy A

doi:10.37871/jbres1681

Cited by 2 publications

(2 citation statements)

References 22 publications

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“…In the present study, the Regional Climate Model (RegCM; version 4.7; [7]; hereafter RegCM4) was used. Except for the boundary layer schemes, the RegCM4 domain and simulations were confi gured following [15]. To address the sensitivity of the daily mean air temperature to the boundary layer schemes, two simulations were conducted.…”

Section: Methodsmentioning

confidence: 99%

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On the Sensitivity of the Daily Mean Air Temperature of Egypt to Boundary Layer Schemes Using a High-Resolution Regional Climate Model (RegCM4)

Anwar¹,

Mostafa²

2023

J Biomed Res Environ Sci

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Introduction: Boundary layer processes play an important role in controlling the daily mean air temperature through exchange of turbulent fluxes of water and energy between the ground surface and the atmosphere. Therefore, it is important to explore the role of boundary layer parameterization in simulating the daily mean air temperature particularly on a regional scale. Methods: To accomplish this task, two simulations were conducted to assess the sensitivity of the mean air Temperature (TMP) of Egypt to boundary layer schemes (Holtslag; HOLT and University of Washington; UW) within the framework of the Regional Climate Model (RegCM4). The RegCM4 was downscaled by the ERA-Interim reanalysis of 1.5 degrees with 25 km horizontal grid spacing over the period 1997-2017. Additionally, ERA5 reanalysis product was used as the observational dataset for the variables: the Total Cloud Cover (CLT), surface short and long wave radiation fluxes (RSDS and RLDS), Skin Temperature (TS), surface Wind Speed (WS), Sensible Heat Flux (HFSS) and TMP. Results: There is no difference between HOLT and UW regarding the CLT and RSDS; while the UW reduces the bias of the RLDS and WS relative to HOLT particularly in the summer and autumn seasons in comparison with ERA5. Furthermore, HOLT and UW schemes showed a considerable impact on the simulated TS. For instance, UW reduces the TS bias relative to HOLT in all seasons but in the spring and winter seasons; UW induces a negative bias more than HOLT. Concerning the HFSS, UW shows a higher bias than HOLT mainly in the summer and autumn seasons. Because of the noted changes of the simulated HFSS and TS, the UW succeeds in reducing the warm bias of the TMP (noted in the HOLT) in all seasons in comparison with the ERA5. With respect to in-situ observations, the HOLT/UW performance varies with the location as well as the month. Conclusion: The UW scheme can be recommended for future studies concerning the future climate change of Egypt concerning the regional scale. However for a point scale, caution is needed in interpreting the results with respect to the in-situ observations except for Asswan where HOLT can be recommended.

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Section: Methodsmentioning

confidence: 99%

“…The reader can refer to [2,7,8] for details of the PBL schemes. It is important to highlight that direct-downscaling was adopted for the two simulations as recommended by [15].…”

Section: Methodsmentioning

confidence: 99%

On the Sensitivity of the Daily Mean Air Temperature of Egypt to Boundary Layer Schemes Using a High-Resolution Regional Climate Model (RegCM4)

Anwar¹,

Mostafa²

2023

J Biomed Res Environ Sci

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The Influence of Dynamical Downscaling and Boundary Layer Selection on Egypt’s Potential Evapotranspiration using a Calibrated Version of the Hargreaves-samani Equation: RegCM4 Approach

Samy A,

Ankur

2024

IgMin Res

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Potential Evapotranspiration (PET) is an important variable for monitoring daily agricultural activity as well as meteorological drought. Therefore, it is necessary to investigate the influence of different options of the physical dynamical downscaling and boundary layer schemes on the simulated PET. Using the RegCM4 regional climate model, four simulations were conducted (two for each case) in the period 1997 to 2017. In all simulations, the RegCM4 was configured with 25 km resolution and downscaled by the ERA-Interim reanalysis dataset. To ensure a reliable estimation of the PET, a calibrated version of the Hargreaves-Samani equation was adopted. A high-resolution product of the ERA5 was used as the observational dataset. Results showed that the simulated PET is insensitive either to the dynamical downscaling or the boundary layer options. Concerning the annual climatological cycle, the RegCM4’s performance varies with month and location. Quantitatively, a root mean square error lies between 1 mm and 1.6 mm day-1, the Nash-Sutcliffe efficiency between 0.2 and 0.6, and the coefficient of determination between 0.5 and 0.75. Additionally, the Linear Scaling (LS) method showed its added value in the evaluation/validation periods. In conclusion, the RegCM4 can be used to develop a regional PET map of Egypt using the LS either in the present climate or under different future scenarios.

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Influence of Direct-Downscaling and One-Way Nesting on Daily Mean Air Temperature of Egypt Using the RegCM4

Cited by 2 publications

References 22 publications

On the Sensitivity of the Daily Mean Air Temperature of Egypt to Boundary Layer Schemes Using a High-Resolution Regional Climate Model (RegCM4)

On the Sensitivity of the Daily Mean Air Temperature of Egypt to Boundary Layer Schemes Using a High-Resolution Regional Climate Model (RegCM4)

The Influence of Dynamical Downscaling and Boundary Layer Selection on Egypt’s Potential Evapotranspiration using a Calibrated Version of the Hargreaves-samani Equation: RegCM4 Approach

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