Page 38 - 《高原气象》2026年第2期

高 原 气 象 45 卷
338

Comparative Evaluation of CRA Reanalysis by Using the Intensive

Radiosonde Observations over the Qinghai-Xizang
Plateau in Summer

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LIAO Jie ， YUAN Fang ， ZHAO Ping ， HAN Yizhe 1
1
（1. National Meteorological Information Center， Beijing 100081， China；
2. Chinese Academy of Meteorological Sciences， Beijing 100081， China）
Abstract： The weather and climate of the Qinghai-Xizang Plateau （QXP） not only exert profound influences on
Asian regional climate but also regulate broader Northern Hemisphere climate patterns. Various global atmospher‐
ic reanalysis datasets developed abroad have been extensively utilized to characterize the QXP's climate features.
In 2020， the China Meteorological Administration released its first-generation global atmospheric reanalysis
product （CRA）， which demonstrated superior performance in regions with dense conventional observations， yet
its skill over the QXP remains unclear. In this study， we performed an independent evaluation of CRA's upper-air
temperature， wind fields， and relative humidity using 686 high-quality， non-assimilated radiosonde profiles
from five stations collected during June-August 2014 in the 3rd Qinghai-Xizang Plateau Atmospheric Scientific
Experiment. A non-independent assessment was also performed using routine observations from 21 sounding sta‐
tions across the QXP and adjacent areas. Results were compared with those from ERA-Interim， ERA5， and JRA-
55 reanalysis datasets. Non-independent validation results demonstrate that in the troposphere and lower strato‐
sphere， correlation coefficients of temperature and wind speed between CRA and operational radiosonde observa‐
tions exceed 0. 9. Relative to operational radiosondes， CRA temperature bias of 400 hPa and 500 hPa approach‐
ing 0 ℃. The near-surface zonal wind RMSE of CRA is about 2. 5 m·s ， decreasing gradually with altitude to
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1. 5 m·s at 100 hPa. Relative humidity RMSE remains below 20% across all altitude layers. Independent valida‐
tion results indicate that errors in air temperature and wind speed over the eastern Qinghai-Xizang Plateau are
generally smaller than those over the western plateau， whereas relative humidity errors are larger in the east.
From 600 hPa to 30 hPa， the mean root-mean-square errors （RMSE） of CRA relative to radiosonde for tempera‐
ture， zonal wind， and meridional wind are 1. 38 ℃， 3. 19 m·s ， and 3. 22 m·s in the western Qinghai-Xizang
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Plateau， respectively； and 1. 16 ℃， 2. 65 m·s ， and 2. 90 m·s in the eastern Qinghai-Xizang Plateau， respec‐
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tively. Errors in the western QXP were slightly larger than in the east and exhibited pronounced diurnal variabili‐
ty. Maximum temperature and relative humidity errors below 600 hPa occur in the afternoon. At 500 hPa， peak
relative humidity errors appear in the evening. CRA objectively reproduces the QXP’s vertical structures of tem‐
perature， wind speed， and relative humidity. Compared to other reanalysis products， CRA’s relative humidity
estimates were closest to radiosonde observations， and wind field errors were slightly higher than those of other
datasets but did not exceed 0. 4 m·s on average.
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Key words： Qinghai-Xizang Plateau （QXP）； reanalysis； radiosonde； evaluation