Evaluation of medium-range weather forecasts about Korea Institute of Atmospheric Prediction Systems (KIAPS) Integrated Model System (KIM)

Abstract:

The Korea Institute of Atmospheric Prediction Systems (KIAPS) is a government funded non-profit research and development institute located in Seoul, South Korea. KIAPS was established in 2011 by the Korea Meteorological Administration, KIAPS’ primary sponsor. KIAPS is developing the KIAPS Integrated Model System (KIM), a backbone for the next-generation operational global numerical weather prediction (NWP) system. The KIM will be a unified model that can be used for global modeling as well as local areas, particularly optimized to topographic and meteorological features of the Korean Peninsula.

We have been completed developing major model components based on KIAPS own research and release the KIAPS beta version model on September 2014. We evaluated the results of KIM by using verification system developed KIAPS, it is composed of standard verification score based on WMO report. The system consists of four parts: verification against analysis, observations, vertical verification and quantitative precipitation forecasts.

The results of verification against analysis, we found that increase of error for temperature under 700 hPa. In case of MSLP, poor performance except for tropical region is represented, and the increase of error for geopotential height is shown in tropical region. For verification against observations, positive bias is represented for upper level geopotential height, for low level wind speed in tropical region in summer, for all level wind speed in Northern Hemisphere in winter, and for specific humidity in Northern Hemisphere in summer. As previously stated about the result against analysis, cold bias for low level temperature is shown in Northern Hemisphere in summer. In case of verification for rain about KIM, the model value is underestimated in heavy rain category in summer, on the contrary, that is overestimated in heavy rain category in winter. Overall, there is overestimation in ocean for all models. Our findings indicate that continuing efforts should be taken in physics and dynamics of model to improve the skill of NWP.