A Study of Iterative QC-BC Method for AMSU-A in the KIAPS Data Assimilation System

KIAPS 자료동화 시스템에서 AMSU-A의 품질검사 및 편향보정 반복기법에 관한 연구

  • 정한별 ((재)한국형수치예보모델개발사업단) ;
  • 전형욱 ((재)한국형수치예보모델개발사업단) ;
  • 이시혜 ((재)한국형수치예보모델개발사업단)
  • Received : 2019.02.07
  • Accepted : 2019.07.02
  • Published : 2019.09.30


Bias correction (BC) and quality control (QC) are essential steps for the proper use of satellite observations in data assimilation (DA) system. BC should be calculated over quality controlled observation. And also QC should be performed for bias corrected observation. In the Korea Institute of Atmospheric Prediction Systems (KIAPS) Package for Observation Processing (KPOP), we adopted an adaptive BC method that calculates the BC coefficients with background at the analysis time rather than using static BC coefficients. In this study, we have developed an iterative QC-BC method for Advanced Microwave Sounding Unit-A (AMSU-A) to reduce the negative feedback from the interaction between BC and QC. The new iterative QC-BC is evaluated in the KIAPS 3-dimensional variational (3DVAR) DA cycle for January 2016. The iterative QC-BC method for AMSU-A shows globally significant benefits for error reduction of the temperature. The positive impacts for the temperature were predominant at latitudes of $30^{\circ}{\sim}90^{\circ}$ of both hemispheres. Moreover, the background warm bias across the troposphere is decreased. Even though AMSU-A is mainly designed for atmospheric temperature sounding, the improvement of AMSU-A pre-processing module has a positive impact on the wind component over latitudes of $30^{\circ}S$ near upper-troposphere, respectively. Consequently, the 3-day-forecast-accuracy is improved about 1% for temperature and zonal wind in the troposphere.


KPOP;AMSU-A;bias correction;quality control;iterative QC-BC method


Supported by : 한국형수치예보모델개발사업단


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