The impact of T-PARC 2008 dropsonde observations on typhoon track forecasting

Abstract

The THORPEX-Pacific Asian Regional Campaign 2008 (T-PARC 2008) was performed during the period of August 1 through October 4, 2008, and mainly focused on the genesis, intensification, recurvature, and extra-tropical transition over the western North Pacific in collaboration with TCS-08 and DOTSTAR. This study investigates the impact of dropsonde observations on the improvement of predictive skills for Typhoon Sinlaku (0813) and Jangmi (0815) during T-PARC 2008. Twelve and six cases were selected for Sinlaku and Jangmi, respectively. The dropsonde data were assimilated by the Weather Research and Forecasting (WRF)-Three-Dimensional Variational system (3DVAR), and then the typhoon track was obtained by running a WRF model for up to 72 hours. Consequently, the assimilation of the dropsonde data had positive impacts on the typhoon track forecast and lead to mean track error reductions of 22.5% and 17.0% for Typhoon Sinlaku and Jangmi, respectively. Subsequent experiments were also conducted to determine the sensitivities of storm activity in the horizontal and vertical distributions and the dynamic and thermodynamic variables using the dropsonde data. The results show that sondes released south of storms around the middle troposphere (500~850 hPa) are more effective in improving the track forecast. The dynamic variables mainly affect the storm tracks, while the thermodynamic variables mainly affect the central pressure of the storm.

Impact of local data assimilation on tropical cyclone predictions over the Bay of Bengal using the ARW model

“…can be reduced using observational assimilation (Wu et al, 2007;Park et al, 2008;Pu, 2009;Kim et al, 2010). There has been a considerable increase in the number of observations, both from conventional (surface and upper air) and satellite (cloud motion vectors, scatterometer winds, radiances sensitive to temperature or humidity profile) sources over the NIO region in the recent times.…”

Strategy for the meteorological and environmental airborne observations over the Korean Peninsula

“…NIMR also took part in the THORPEX (The Observing System Research and Predictability Experiment) Pacific Asian Regional Campaign (T-PARC) in August to October, 2008 (Kim et al, 2010), which was a multi-national field campaign that addresses the shorter-range dynamics and forecast skill of one region (Eastern Asia and the western North Pacific) and its downstream impact on the medium-range dynamics and forecast skill of another region (in particular, the eastern North Pacific and North America) (Wu et al, 2005;Elsberry and Harr, 2008). Kim et al (2010) investigate the impact of dropsonde observations on the improvement of predictive skills in numerical models for Typhoons Sinlaku (August 13) and Jangmi (August 15) during T-PARC 2008.…”

“…Kim et al (2010) investigate the impact of dropsonde observations on the improvement of predictive skills in numerical models for Typhoons Sinlaku (August 13) and Jangmi (August 15) during T-PARC 2008. The 328 sondes were dropped during the T-PARC periods of August 1 to October 5, 2008 including Typhoons Sinlaku and Jangmi.…”

Change in the tropical cyclone activity around Korea by the East Asian summer monsoon

“…However, most of studies on TCs that affected or made landfall on Korea have been concentrated on the precipitation and strong winds that accompanied by TCs or their modeling due to the property and human life damage (Kim and Lee 2007;Kim et al 2010;Park and Kim 2010). However, understanding the trend of the annual frequency of TCs that affected or made landfall on Korea and those climate factors that cause the trend should be also helpful for seasonal forecasting of TCs or preparation for disasters resulting from TCs.…”