Implementation of cloud water schemes into ECPC G-RSM

Akihiko Shimpo


Six cloud water schemes were implemented into the ECPC G-RSM and tested in global simulations. One is Zhao and Carr cloud water scheme (ZC) currently in use by NCEP models, which predicts cloud water, but cloudiness is diagnosed from cloud water and relative humidity. The second is the Iacobellis and Somerville cloud scheme (IS) being used in the ECPC Single Column Model, which predicts both cloud water and cloud amount based on Tiedtke cloud scheme. In addition, four cloud water schemes (CLD3, CLDW, CLD5 and CLD6), different in complexity (CLD6 being the most complex) developed by Hong (Hong et al., 2004) and now a part of the WRF model, are also tested. These schemes predict multiple cloud substances, ranging from cloud water, cloud ice, rain water, snow and graupel. Cloud amount are calculated from both cloud water and relative humidity with the same manner as ZC in these schemes. 10 year experiment were performed using each cloud water scheme. In the seminar, the impact of cloud water schemes on climatological fields of not only clouds but also other variables will be presented.