We can see from Fig.l that sand dust particles were carried 
upward by the swirling wind flow over the source region. 
  
  
Fig.1 Flow of wind over the source region and isosurfaces of 
velocities of 10, 20, 25, 30 m/s. (a) shows equi-velocity surfaces 
at 2007.3.30 06:00 and (b) shows those at 2007.3.30 12:00. 
We estimated the released region of the sand dust observed in 
Japan on March 21, 2010 in the same way as the case of dust 
event of April 1, 2007. As a result, it was found that sand dust 
particles were released at the Badainjaran desert from 3:00 to 
12:00 on March 19. 
In order to estimate the released mass flux of sand dust particles 
at the estimated source region, we used the transport simulation 
software (Aria Technologies 2007) to compute the 3- 
dimensional concentration distribution of Asian dust. The 
results of the long-range transport simulation of Asian dust are 
easily visualized and analyzed, by using the savi3D graphic 
package given in Aria regional package. We determined the 
released mass flux such that the computed concentration of 
Asian dust is nearly equal to the concentration of Suspended 
Particulate Matter (SPM) measured at various measurement 
places in Japan. The concentration of the SPM is measured 
every one hour at more than 2000 measurement spots in Japan. 
We acquired SPM data from Atmospheric Environmental 
Regional Observation System (AEROS) in Japan and estimated 
the concentration of SPM and the arrival time of Asian dust 
clouds at various places in Japan. In the case of dust event 
observed in Japan on April 1, 2007, the evaluation results are 
shown in our paper (Kusaka 2011). It was found that the 
concentration of Asian dust obtained from the simulation almost 
corresponds to that of SPM measured at several places in Japan. 
In the case of dust event on March 21, 2010, the evaluation 
results for the arrival time and the concentration of Asian dust 
at 7 Prefectures in Japan are shown in Table 1. We can see from 
Table 1 that the long-range transport simulation of Asian dust 
provides good results. Fig.2 shows the concentration 
distribution of Asian dust at 21:00 on March 20, 2010 obtained 
from the long-range transport simulation using the estimated 
mass flux at the source region. In Fig. 2, Asian dust clouds with 
the concentration of 0.6 mg/m’ and topographical features in the 
East Asia are shown. 
ROSA transport 
03/29/2010 21:00:0.06 
  
Fig.2 Dust clouds with the concentration larger than 0.6mg/m’ 
at 21:00 on March 20, 2010 
Table 1 Evaluation results for the arival time and 
the concentration of Asian dust (mg/m?) 
  
  
  
SPM Evaluation 
Arival time Concentration Arival time Concentration 
Nagasaki 2010.3.20 22:00 0.6 © OQ 
Fukuoka 2010.3.20 23:00 0.6 C Q 
Kumamoto | 2010.3.21 0:00 0.6 2010.3.20 23:00 Q 
Hyogo 2010.3.21 3:30 0.3 © Q 
Kyoto 2010.3.21 5:00 0.3 Q Q 
Ishikawa 2010.3.21 3:30 0.4 (^ Q 
Akita 2010.3.21 5:00 0.2 2010.3.21 6:00 O 
  
  
  
3. ANIMATION OF 3D ASIAN DUST CLOUDS IN THE 
GOOGLE EARTH 
The long-range transport simulation software given by Aria 
regional package allows us to generate image files of the 
concentration distribution of Asian dust as shown in Fig.2. By 
using these images of Asian dust clouds, we have made an 
animation of the concentration distribution of Asian dust in the 
Google Earth (Kusaka 2009, 2011) to open the movement of the 
simulated Asian dust clouds to the public. In this case, the dust 
cloud is represented as the image and so we can clearly see the 
movement and extent of Asian dust clouds in the Google Earth. 
However, we are not able to see the widely spread dust cloud 
covering the sky. It is expected that we represent the Asian dust 
cloud 3-dimensionally in the Google Earth as if we would look 
at the dust cloud covering the sky from the ground surface. 
3.1 Generation of 3D Asian Dust Clouds 
The savi3D software allows us to output files of 3D dust clouds 
in the McRAF file format based on the netCDF (Network 
Common Data Form) format. However, it is difficult to process 
them by means of the typical CG and image processing software. 
The software for transforming dust clouds with the MeRAF 
  
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