The impact of lightning data assimilation on WRF simulations of Typhoon Jangmi (2008)

WRF simulations of Typhoon Jangmi (2008) have been run to investigate the impact of lightning data assimilation on an intensifying tropical cyclone. We have run four simulations initialized with: i) no bogus storm or lightning data, ii) a bogus storm but no lightning data assimilated, iii) a bogus storm with weak lightning forcing, and iv) a bogus storm with strong lightning forcing. The lightning data assimilation method adjusts the model's latent heating profiles during the simulation. Lightning data is assimilated on a 15 km resolution domain for the first 6 hours of the simulation. For the remainder of each simulation a storm following (3 km resolution) domain is introduced. Preliminary results show an improvement in the intensity when the weak lightning assimilation is applied. In addition, the lightning data assimilation cases produce clear storm structural differences to the cases without lightning data, both during, and persisting well after the assimilation period. The results suggest that stronger lightning assimilation can produce a storm with a larger eye and greater rainfall.