Improvement in TC analysis using dual methods of ADT and SDT operationally by COMS data in NMSC/KMA

KMA has applied semi-ADT (Advanced Dvorak Technique) method, in which a analyzer decides manually TC's position and CI (Current Intensity) is estimated automatically by ADT introduced from SSEC/UW-Madison (Space Science Engineering Center/University of Wisconsin-Madison) since 2005.

To switch into auto-ADT from semi-ADT, NMSC/KMA tested auto-ADT method for estimating center position and CI of TCs during the year of 2014 using COMS (Communication, Ocean, and Meteorological Satellite) data. In addition to test auto-ADT, analyzers practiced and trained the skill of SDT methods. The result of TC information by auto-ADT is compared with RSMC Tokyo best track data for 23 TCs occurred in Northwestern Pacific. The RMSE is about 62km for center position, 13.1hPa for central minimum pressure and 8.2m/s for maximum wind speed. And the RMSE for CI is 0.8 compared with SAREP (Satellite Report of JMA). NMSC/KMA has improved TC analysis and supporting TC forecast by applying ADT and SDT methods at the same time in 2015.

In order to clarify the TC position differences for strong and weak stages, we have compared TC positions of KMA/NMSC and RSMC Tokyo best track from 2007 to 2013. According to the preliminary results, the distance between them is about 40km for CI 3.0 or weaker, 27km for CI 3.5~5.0, and 9km for CI 5.5~8.0, respectively. Also, the position difference for each cloud pattern is about 39km for SHEAR, 28km for CDO, 30km for CURVED BAND, and 10km for EYE, respectively. It is assured that there is the largest position difference in the weakening phase, Shear pattern of TC.