(-B4, 2012
opter UAV for
RS Workshop of
tion.
pplies Resources
JSA.
re Processing-A
er Saddle River,
2011. Snowfall
nal Charter. In:
/ for GeoSpatial
a. A Near Real-
ping Data With
su, Korea.
s of a Real-time
1 in Emergency
Yeosu, Korea.
-Low Altitude
| Archives of the
ial Information
im, S., 2011. A
system by using
Korea.
volunteers for
indslide disaster
THE VISUALIZATION METHOD OF THE 3D CONCENTRATION DISTRIBUTION OF
ASIAN DUST IN THE GOOGLE EARTH
W. Okuda* , T. Kusaka ^*
“ Yamatoku Corporation, Nagasakadai, Kanazawa, JAPAN — wataru! 2ctb@hotmail.com
*Kanazawa Institute of Technology, Nonoichimachi Ishikawa, JAPAN — kusaka@neptune.kanazawa-it.ac. Jp
Commission IV, WG IV/8
KEY WORDS: 3D Asian dust cloud, Long-range transport simulation, Google Earth, 3D display of wind field
ABSTRACT:
The Asian dust (called "Kosa" in Japan) transported from desert areas in the northern China often covers over East Asia in the late
winter and spring seasons. In this study, first of all, for dust events observed at various places in Japan on April 1, 2007 and March
21, 2010, the long-range transport simulation of Asian dust from desert areas in the northern China to Japan is carried out. Next, the
method for representing 3D dust clouds by means of the image overlay functionality provided in the Google Earth is described. Since
it is very difficult to display 3D dust clouds along the curvature of the Earth on the global scale, the 3D dust cloud distributed at the
altitude of about 6300m was divided into many thin layers, each of which is the same thickness. After cach of layers was transformed
to the image layer, each image layer was displayed at the appropriate altitude in the Google Earth. Thus obtained image layers were
displayed every an hour in the Google Earth. Finally, it is shown that 3D Asian dust clouds generated by the method described in
this study are represented as smooth 3D cloud objects even if we looked at Asian dust clouds transversely in the Google Earth.
1. INTRODUCTION
The Asian dust transported widely from desert areas in the
northern China often covers over East Asia in the late winter
and spring seasons. Fine dust particles will have harmful
influence on our health. It is, therefore, important to see the
extent and movement of Asian dust clouds over East Asia. In
order to find out the source region and mass flux of sand dusts
transported to Japan from arid areas in the northern China, we
have carried out the long-range 3-dimensional transport
simulation of Asian dust clouds and displayed the computed
concentration distribution of dust clouds in a map system
(Kusaka, 2009, 2003, 201 1). In order to see the movement of
dust clouds 3-dimensionally in the Google Earth, we
transformed the file format of 3D dust clouds generated by the
long-range transport simulation into the COLLADA file format
such as the DAE format. However, it is very difficult to
represent 3D dust clouds that are successfully placed along the
curvature of the Earth on the global scale in the Google Earth.
In this study, a method for visualizing 3D Asian dust clouds in
the Google Earth is described, and the time variation of the 3D
concentration distribution of Asian dust clouds derived from the
long-range transport simulation is also shown in the Google
Earth. We computed the 3D concentration distribution of dust
clouds over East Asia in cases of dust events observed in Japan
on April 1 to 2, 2007 and March 21, 2010. We first transform
the file format of 3D concentration distribution of Asian dust
clouds obtained from the transport simulation into the VRML
format with the Wrl file extension. After that, we read them in
terms of the 3dsMAX software and then divided 3D Asian dust
clouds distributed at the altitude of about 6000m into many thin
layers and displayed cach of layers at the appropriate altitude in
the Google Earth. Thus obtained image layers are displayed
“very an hour in the Google Earth. In order to animate the
Movement of 3D Asian dust clouds in the Google Earth, we also
developed the software for automatically generating the KML
Script file and the image folder in which images corresponding
to each layer of 3D dust clouds are saved. As a result, it is
shown that 3D Asian dust clouds created in the present study
are recognized as smooth 3D objects even if we zoom in the
Google Earth.
2. LONG-RANGE TRANSPORT SIMULATION OF
ASIAN DUST
In order to obtain the time variation of the 3D concentration
distribution of Asian dust clouds for East Asia, we need to solve
the 3-dimensional diffusion equation. We used the Aria regional
package (Aria Technologies 2007) developed by Aria
Technologies, France to carry out the long-range transport
simulation of the Asian dust. The Aria regional package consists
of the operational meteorological software based on MMS and
the continental Eulerian dispersion software using the
CHEMERE multi-scale model. The Aria regional program
allows us to compute the diffusion and depletion of Asian dust
using US-NCEP GRIB data. The most important and difficult
problem for the transport simulation of the Asian dust is to
determine initial conditions such as source regions, the released
time and mass flux of the sand dust.
We have reported how we determine initial conditions to solve
the 3D diffusion equation (Kusaka 2003, 2009). That method
was also used in this study. The source region estimated for dust
events observed at various places in Japan on April 1 and 2,
2007 was located near (44.03, 111.60) at the latitude-longitude
coordinates. The released time was about 00:00 on March 30,
2007 In addition, to check how dust particles rise with the
ascending current near the estimated source region, we
visualized the 3-dimensional flow of wind using the graphic
package, savi3D, provided in the Aria regional package. Fig.1
shows surfaces with the same velocity at the altitude of
1000hPa to 750hPa near the source region. In Fig.1(a) and 1(b),
isosurfaces with values of 10, 20, 25, 30m/s are shown in 4 gray
scales. The brighter region corresponds to the higher velocity.
