Seminar Detail

Joint Seminar: Global highest resolution (870 m) simulation and 10-year history of NICAM

As the availability of computer resources increases, various directions of research can

be pursued with global atmospheric models. The non-hydrostatic icosahedral atmospheric

model (NICAM) was originally developed approximately 10 years ago to run high-resolution

simulations (3.5km) using a high-end supercomputer (the Earth Simulator, JAMSTEC). Now,

on the K computer at RIKEN Advanced Institute for Computational Science (AICS), while the

horizontal mesh size has decreased to less than one kilometer (870 m) over the global domain,

other types of computationally intensive simulations using NICAM have also emerged. Multi

decadal simulations (30 years) with Atmospheric Model Intercomparison Project (AMIP) type

conditions have been performed and counterpart simulations under future conditions were also

conducted to investigate the impacts of global warming on clouds and atmospheric circulation.

Ensemble simulations to predict intra-seasonal variability have also been conducted to

investigate Madden–Julian oscillations (MJO) and the boreal summer intra-seasonal oscillations

(BSISO). Ensemble sizes have been further increased to 10,240 for assimilation via NICAM

and local ensemble transform Kalman filter (NICAM–LETKF). NICAM has also been coupled

with the ocean model COCO to study atmosphere–ocean interactions. Various options for

clouds and other physical schemes have been implemented and tested with Earth observation

data from satellites in particular.

In this talk, we review the development and scientific outcomes of NICAM in its 10-

year history and show the results of the convective properties simulated by the 870 m mesh

simulations and their resolution dependency. We find that an essential change in the simulated

convection properties occurs at a grid spacing of approximately 2 km as a global mean. The

differences in the convective properties of various types of disturbances and diurnal cycles of

convection are also examined.

Reference:

Satoh, M., Tomita, H., Yashiro, H., Miura, H., Kodama, C., Seiki, T., Noda, A. T., Yamada, Y.,

Goto, D., Sawada, M., Miyoshi, T., Niwa, Y., Hara, M., Ohno, Y., Iga, S., Arakawa, T., Inoue, T.,

Kubokawa, H. (2014) The Non-hydrostatic Icosahedral Atmospheric Model: Description and

development. Progress in Earth and Planetary Science. 1, 18.

24.02.2016

13:30 Uhr

Bundesstr. 53, room 022/023: Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg