نوع مقاله : مقاله پژوهشی
نویسندگان
1 عضو هیات علمی گروه مهندسی نقشه برداری دانشگاه نوشیروانی بابل
2 پژوهشگاه هواشناسی و علوم جو
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Temperature and surface pressure are among the critical variables in various meteorological and climatic applications. Reanalysis products have become valuable sources of temperature and pressure data in recent years and have garnered much attention. Previous studies have shown that due to the elevation difference between reanalysis grids and ground stations, surface pressure and temperature derived from reanalysis products exhibit noticeable biases. The importance of pressure and surface temperature reanalysis data in different applications and the presence of significant errors in the pressure and surface temperature reanalysis products, which depend on the difference in the height of the grid point and the station, encourage the authors to investigate the correction of ERA5 Land (ERA5L) temperature and pressure data over Iran. In this work, using 10 years of measured observations from 202 synoptic stations in Iran, the impact of elevation correction on ERA5L pressure and temperature data was investigated. The authors plan to investigate the amount of the effect of corrections using various methods on the accuracy of surface pressure and temperature parameters in ERA5L reanalysis compared to actual observations. The surface meteorological data in the study area are referenced to the geodetic height system, which is defined based on the distance from the ellipsoidal surface. On the other hand, the geopotential height system has been employed for reanalysis data such as ERA5L. Prior to evaluating and utilizing reanalysis surface temperature and pressure data, the height system of the two datasets were unified. first, the reanalysis values and real observations of temperature and surface pressure at each station from were prepared. After unifying the height systems of the reanalysis and observations, the ERA5L reanalysis data are extrapolated from the grid point height to the ground station elevation. To assess the impact of the applied corrections on the accuracy of the reanalysis data, the values of Mean Error (ME), RMSE, and correlation coefficient (R) were utilized. A comparison of error statistics before and after elevation correction revealed that, in most stations, the accuracy of ERA5L temperature and pressure data improves after elevation correction. The results indicate that, after data calibration, the average bias and Root Mean Squares Error (RMSE) of pressure in the region improved by 96% and 66%, respectively. The positive impact of elevation correction on ERA5L temperature was less pronounced, with average bias and RMSE improving by 68% and 13%, respectively. Furthermore, for the elevation calibration of ERA5L pressure, the Berg model and the two models proposed by Su et al. (2021) were compared. A comparison of error statistics across all stations demonstrated that the performance of the three models did not show significant differences in the Iran region.
کلیدواژهها [English]
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