Current and future carbon budget at Takayama site, Japan, evaluated by a regional climate model and a process-based terrestrial ecosystem model
Kuribayashi, M., N. Noh, T. M. Saitoh, A. Ito, Y. Wakazuki, H. Muraoka
International Journal of Biometeorology
Accurate projection of carbon budget in forest ecosystems under future climate and atmospheric carbon dioxide (CO2) concentration is important to evaluate the function of terrestrial ecosystems, which serve as a major sink of atmospheric CO2. In this study, we examined the effects of spatial resolution of meteorological data on the accuracies of ecosystem model simulation for canopy phenology and carbon budget such as gross primary production (GPP), ecosystem respiration (ER), and net ecosystem production (NEP) of a deciduous forest in Japan. Then, we simulated the future changes in canopy phenology and carbon budget of the forest by incorporating high-resolution meteorological data downscaled by a regional climate model. The ecosystem model overestimated GPP and ER when we inputted low-resolution data, which have warming biases over mountainous landscape. But, it reproduced canopy phenology and carbon budget well, when we inputted high-resolution data. Under the future climate, earlier leaf expansion and delayed leaf fall by about 10 days compared with the present state was simulated, and also, GPP, ER and NEP were estimated to increase by 25.2%, 23.7% and 35.4%, respectively.
若月泰孝, 原政之, 藤田実季子, 馬燮銚, 井上忠雄, 木村富士男, 小池俊雄
72/ 4, I_55-I_60
The incremental dynamical downscaling and analysis system (InDDAS) which has been developed from the pseudo-global-warming method by appending partial functions was applied for a probabilistic regional scale climate change projection with the target regions of Kanto and Japan Alps. In InDDAS, the most reliable future state was projected by a regional climate model (RCM) simulation with an ensemble mean among the climatological increments of multiple general circulation model (GCM) simulations. In addition, the uncertainty of the future projections is estimated by RCM simulations with the multi-modal statistical increments calculated by the singular vector decomposition of the multiple GCMs. An increase of rainfall with the change ratio of 7-16 % was projected in Kanto region, where the most reliable value was 10 %. The change ratios of the vicinity quantiles of extreme rainfall was projected to be larger than that of rainfall and was almost the same as the value explained by the Clausius–Clapeyron effect.
Incremental dynamical downscaling for probabilistic analysis based on multiple GCM projections.
Wakazuki, Y., R. Rasmussen
Geophysical Research Letters
American Geophysical Union
A dynamical downscaling method for probabilistic regional-scale climate change projections was developed to cover the inherent uncertainty associated with multiple general circulation model (GCM) climate simulations. The climatological increments estimated by GCM results were statistically analyzed using the singular vector decomposition. Both positive and negative perturbations from the ensemble mean with the magnitudes of their standard deviations were extracted and added to the ensemble mean of the climatological increments. The analyzed multiple modal increments were utilized to create multiple modal lateral boundary conditions for the future climate regional climate model (RCM) simulations by adding them to reanalysis data. The incremental handling of GCM simulations realized approximated probabilistic climate change projections with the smaller number of RCM simulations. For the probabilistic analysis, three values of a climatological variable simulated by RCMs for a mode were analyzed under an assumption of linear response to the multiple modal perturbations.
Numerical Experiments of Meso-α-Scale Precipitation Systems under Baiu-Front-Like Idealized Environments
Wakazuki Yasutaka, Watanabe Tomoya
Meteorological Society of Japan
11/ 0, 150-155
To investigate the variability of the structure and evolution of meso-α-scale precipitation systems generated in the Baiu frontal zone, numerical experiments using a cloud-resolving non-hydrostatic model were performed with idealized Baiu-front-like environments. The environment was constructed based on hydrostatic and geostrophic balances, and temperature and relative humidity were designed by using Gaussian functions to realize the frontal structure and moist conveyor belt in the lower atmosphere. In order to generate meso-α-scale precipitation systems, temperature perturbation associated with a shallow depression was introduced. Long-lived band-shaped meso-α-scale precipitation systems with the internal multiscale structures as are often observed in the Baiu frontal zone were simulated under the given simplified environments. The variability of features of the meso-α-scale precipitation systems with respect to relative humidity in the middle troposphere in the Baiu frontal zone was examined as an example. The moister environment produced the more rainfall. Additionally, rainfall was intensified under a specific humidity condition.
青山 智夫, 若月 泰孝
Journal of Computer Chemistry, Japan
Society of Computer Chemistry, Japan
14/ 3, 74-76
Under nuclear power plant accident, by the ventilation of containment vessel, suspended particulate matter (SPM) is emitted; it attracts radioactive compounds, and the plume diffuses in air. It soaks into the human body. We are required to run away from the invisible plumes. The routes do not exist at any time. We recognize status soon, and should select priority persons to escape from there. We code a real-time plume tracer, which reads 4D-winds of Meso Scale Model (MSM), calculates time-development of plumes. The precision for reach time of plumes is 3–5 min, inner 8 km points from emission.
A statistical downscaling using high resolution regional climate model simulation results
American Geophysical Union fall meeting
Incremental dynamical downscaling for probabilistic climate change projection and a dynamical approach for precipitation nowcast
ICHARM Research & Development Seminar
American Geophysical Union