Abstract: A long-term wide-area airflow field data computing unit (101) obtains hourly airflow field data for one year by RAMS or the like using weather data of global weather reanalysis data G as entrance boundary conditions for a calculation region. An atmospheric stability calculation/addition unit (102) obtains the stabilities of the representative airflow field data of the respective airflow field data, and adds the obtained stabilities to the respective airflow field data. A wind direction-based/atmospheric stability-based classification unit (103) classifies the respective airflow field data into cases covering different combinations of wind directions and atmospheric stabilities.

Abstract: A diffusion status prediction method and system for a diffused substance are disclosed. The diffused substance is replaced by particles, and positions which the particles generated from an emission source arrive at are found by computation. The arrival positions and a post-emission elapsed time are recorded in association with each other. Also, intensity data showing the intensities of the particles during the passage of the post-emission elapsed time are set. Then, the intensity of the particles at the point in time at which the particles were generated is found by reference to the intensity data based on the post-emission elapsed time. For each particle, the arrival position, the post-emission elapsed time, and the intensity are recorded in association with each other. The concentration of the diffused substance in a predetermined area after a lapse of a predetermined time can be determined by adding up the intensities of the particles present in the predetermined area.

Abstract: A diffusion status prediction method and system for a diffused substance are disclosed. The diffused substance is replaced by particles, and positions which the particles generated from an emission source arrive at are found by computation. The arrival positions and a post-emission elapsed time are recorded in association with each other. Also, intensity data showing the intensities of the particles during the passage of the post-emission elapsed time are set. Then, the intensity of the particles at the point in time at which the particles were generated is found by reference to the intensity data based on the post-emission elapsed time. For each particle, the arrival position, the post-emission elapsed time, and the intensity are recorded in association with each other. The concentration of the diffused substance in a predetermined area after a lapse of a predetermined time can be determined by adding up the intensities of the particles present in the predetermined area.

Abstract: To determine a gas status (wind direction, wind speed), which is detailed in terms of space and time, from meteorological observation data, such as meteorological GPV, which are rough in terms of space and time, initial conditions and boundary conditions set based on the meteorological observation data are incorporated into differential equations for analysis of atmospheric phenomena, and computations are performed by a parallel computer 11. For the computations, a computation period is divided, for example, into four parts. Computations for the respective divisional computation periods are allocated to four processing units CPU's #1˜#4 and performed simultaneously and parallelly. The results of the computations by the processing units CPU's #1˜#4 are combined, whereby the gas status (wind direction, wind speed) detailed in terms of space and time during the entire computation period can be determined.

Abstract: To determine a gas status (wind direction, wind speed), which is detailed in terms of space and time, from meteorological observation data, such as meteorological GPV, which are rough in terms of space and time, initial conditions and boundary conditions set based on the meteorological observation data are incorporated into differential equations for analysis of atmospheric phenomena, and computations are performed by a parallel computer 11. For the computations, a computation period is divided, for example, into four parts. Computations for the respective divisional computation periods are allocated to four processing units CPU's #1˜#4 and performed simultaneously and parallelly. The results of the computations by the processing units CPU's #1˜#4 are combined, whereby the gas status (wind direction, wind speed) detailed in terms of space and time during the entire computation period can be determined.