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Last update: 24 March 2009
In this study, 3-PG model which is one of ecological modelling is focused because it is stand level based model performing the high accuracy result. 3-PG model is extended in two ways. The first is to develop for net ecosystem productivity (NEP) estimation in deciduous broadleaf forest by doing the parameterizations and including the respiration part into the model. The second is to extend it from point based model to spatial dimensions by coupling with the remotely sensed data. Then, 3-PG mode is namely Spatial 3-PG model. Two flux towers at Hitsujigaoka and Takayama were selected, which have been observing the meteorological data and ecological characteristics. The major vegetation type is deciduous broadleaf forest. The data from flux towers are used as the main input parameters in Spatial 3-PG. Not only for the input data into the model, it is also used to validate the results such as GPP and NEP which are the main outputs of Spatial 3-PG model. The results showed that average NEP estimation from 2002 to 2005 was 459 and 359 gC m-2 year-1 at Hitsujigaoka and Takayama respectively, with root mean square as 0.94 and 0.96 at Hitsujigaoka and Takayama respectively.
Chemical tracers are widely used to investigate the ocean circulation, water mass formation rate, and mixing and ventilation processes. Anthropogenic gas such as chlorofluorocarbon (CFC) is inert transit tracer in the ocean, similar in some ways to anthropogenic CO2, and provides information on the ocean circulation and its variability on timescale of months to decade. We have carried out CFC-11 simulation to investigate the formation and spreading of Subantarctic mode water (SAMW) and Antarctic intermediate water (AAIW) using an eddy-resolving ocean general circulation model. The model has a horizontal grid scale of 0.1 degree and 54 vertical levels. A model is forced by a climatological data of NCEP/NCAR. The model exhibits considerable skill in reproducing the section along Greenwich Meridian (AJAX), 30E (WOCE I06SB), 115E (WOCE I09S), and 170W (WOCE P15S). The high CFC-11 water penetrates to 1000 m depth between 50S and 40S by the SAMW and AAIW ventilation for each section. In the distribution of CFC-11 inventory in 1994, the model is a good performance to observed distribution (GLODAP), especially between 60S and 30S. Distribution of CFC-11 inventory in 26.5-27.0 (SAMW) and 27.0-27.4 (AAIW) in the model is also close to observed. The eddy-resolving model explicitly simulates meso-scale eddies and improves the structure of upper ocean stratification in the Southern Ocean.
Biogeochemical model (DAYCENT) is coupled to the newly developed land surface flux model. The land surface flux model is based on the physiological photosynthetic and stomatal model, energy transfer model, and energy balance model with sub-daily time step. Biogeochemical model consists of C, N, water compartment modules and its forest production model depends on the parameterization. To couple land surface flux model to biogeochemical model, accurate daily forest production rate and evaptranspiration rate are provided to biogeochamical model. This coupled model results (GPP, LE, NEE) are validated with flux measurement data, whose data are sampled under different climate / vegetation condition.
Earth system model is now being developed for the future projection of climate change. In the Earth system model, SEIB-DGVM is supposed to work as terrestrial carbon and vegetation dynamics modules. For checking the behavior of SEIB-DGVM in the Earth system model, AGCM is coupled to SEIB-DGVM and simulation is executed. Under the pre-industrial climate condition and CO2 concentration, terrestrial carbon stocks and fluxes reached to equilibrium state (GPP is about 140 PgC/yr and NPP is about 60 PgC/yr). Vegetation distribution is roughly represented compared to the current condition.
Hanasaki crab is tasty and one of important fisheries target in the eastern Hokkaido. They are caught as a tourism highlight, and also as substitute for hairy crab and red king crab the stocks of which have decreased. Because of overfishing, stock of Hanasaki crab is decline in recent years. But, their ecology has not been revealed. Ikeda et al. developed the Micro-Satellite DNA Marker and examined the genetic diversity of their local populations of Sakhalin and Nemuro. They pointed out that significant genetic differences between Sakhalin population and Nemuro population. This study intends to identify possible mechanism that causes the genetic difference between Sakhalin population and Nemuro population, and to contribute to resource management of Hanasaki crab. We used POM as physical model, the horizontal grid scale of which is 1/6 degree. The vertical grids are 20 layers, upper 10 layers are cartesian coordinate with 2m thickness, and lower 10 layers are sigma coordinate. The simulation was conducted for 3 years from 1999 to 2001, For the calculation of a dispersal of lalrvae, a simple Lagrangean model is used. The particle positions are calculated from daily averaged surface current output from POM. Larvae hatch out every day from 5may 1st to 10th. We set settling term at the period during 40 to 50 days after hatching out, and larvae which were advected in the coastal region during this settling term can be survived. The results were quite different from those the Micro-Satellite DNA Marker.