• Title/Summary/Keyword: Hollingsworth and Lonnberg

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Diagnostics of Observation Error of Satellite Radiance Data in Korean Integrated Model (KIM) Data Assimilation System (한국형수치예보모델 자료동화에서 위성 복사자료 관측오차 진단 및 영향 평가)

  • Kim, Hyeyoung;Kang, Jeon-Ho;Kwon, In-Hyuk
    • Atmosphere
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    • v.32 no.4
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    • pp.263-276
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    • 2022
  • The observation error of satellite radiation data that assimilated into the Korean Integrated Model (KIM) was diagnosed by applying the Hollingsworth and Lönnberg and Desrozier techniques commonly used. The magnitude and correlation of the observation error, and the degree of contribution for the satellite radiance data were calculated. The observation errors of the similar device, such as Advanced Technology Microwave Sounder (ATMS) and Advanced Microwave Sounding Unit-A shows different characteristics. The model resolution accounts for only 1% of the observation error, and seasonal variation is not significant factor, either. The observation error used in the KIM is amplified by 3-8 times compared to the diagnosed value or standard deviation of first-guess departures. The new inflation value was calculated based on the correlation between channels and the ratio of background error and observation error. As a result of performing the model sensitivity evaluation by applying the newly inflated observation error of ATMS, the error of temperature and water vapor analysis field were decreased. And temperature and water vapor forecast field have been significantly improved, so the accuracy of precipitation prediction has also been increased by 1.7% on average in Asia especially.