15:30 〜 16:00
★ [ACG30-18] 経験モデルを用いた土壌N_{2}Oガス放出の全球スケールの推定
キーワード：土壌, 亜酸化窒素, モデル, 窒素
Nitrous oxide (N2O) flux is one of the major greenhouse gas fluxes from terrestrial ecosystems. N2O is generally released from soil surface to the atmosphere. In this study, a semi-empirical model was developed through modifying a model for soil CO2 flux (Raich et al. 2002), and the global distribution of N2O flux from soil was examined. The model consists of the functions of nitrogen, air temperature, and precipitation and the parameters of the functions were determined using a global dataset of N2O emission (Stehfest and Bouwman 2006). The model was applied at a spatial resolution of 5-minute and at a monthly time resolution.
The preliminary calculation revealed that the total amount of N2O emission was 14 Tg N yr-1, and the monthly flux showed a clear seasonality, and was highest in August and lowest in February. The dry natural land is the major source of N2O emission while the dry cultivated land was the second major source. Latitudinally, the flux was high around 30—40 degreeN and 10 degreeS—10 degreeN. These results were still based on limited data, especially for wet ecosystems, and will be updated in future.
The preliminary calculation revealed that the total amount of N2O emission was 14 Tg N yr-1, and the monthly flux showed a clear seasonality, and was highest in August and lowest in February. The dry natural land is the major source of N2O emission while the dry cultivated land was the second major source. Latitudinally, the flux was high around 30—40 degreeN and 10 degreeS—10 degreeN. These results were still based on limited data, especially for wet ecosystems, and will be updated in future.