Transcript PPT 12M

Physico-Chemical Properties of
Yellow Dust Particles and their
Behavior in the Atmosphere
Heavy dust event in Beijing.
Yutaka Ishizaka
HyARC, Nagoya University
Impact of Asian Dust Clouds on Climate and the
Environment
Dust Brown Clouds
Land Use Change
Regional Forcing: Surface and
Atmospheric Radiative Forcing,
Rain Suppression,
Photosynthesis Reduction
Global Radiative
Forcing
Global Climate Change
Regional Climate Change:
Hydrological Cycle; Precipitation,
Weather Extremes/Warming
or Cooling
Ecosystem Response,
Agriculture, Water Availability,
Public Health
Study on yellow dust particles using satellite data
and their ｐhysico-ｃhemical measurements
Source regions
Satellite Data
Emission Rate
Long range
transport
Physico-Chemical
properties of dust
particles
Relationship
with atmospheric
processes
Yellow dust clouds
Visible Image of Satellite GMS at 15JST on 13 April 1979.
Dust PM10 annual emission rates and contribution of types 1-3 sources
on the total annual mean emission of PM10 dust with a US EPA formula.
64%
1%
35%
(Xuan and Sokolik, 2002)
Longitude-height cross
Sections of yellow dust
clouds calculated
from a numerical model.
(In and Park, 2002)
Concentrations of TSP and aerosol chemical
components in relation to distance from the
KOSA source from 14 to 15 April 1998.
Sampling locations.
(Mori et al, 2002)
Mass size distribution of dust particles for heavy and light sandstorms.
105
104
dM/dlogD (μgm-3)
103
102
101
100
10-1
10-2
10-1
100
101
Diameter (μm)
102
Size distribution model of yellow dust
Particles in the atmosphere:
Number size distribution of dust and
background aerosols were given by the
zeroth-order logarithmic distribution
(ZOLD)
2


ln r  ln rm  
dN
 C0 exp  

dr
2 0


(Arao and Ishizaka, 1986)
Unfiltered direct solar
radiation data obtained at 12
stations of the Japan
Meteorological Agency were
analyzed using size
distribution model of yellow
dust particles to estimate
Kosa volume/mass in the
atmosphere.
Left Figure shows
the relationship between
Ångstrom’s turbidity coefficient
and that of Yamamoto.
Where
l0:the extraterrestrial solar
radiation
I: the total radiation at the surface
m: the optical air mass
w: the water vapor content in the
vertical air column
(Arao and Ishizaka, 1986)
Volume distributions of yellow sand dust over Japan on 4-5 May 1981
(Arao and Ishizaka, 1986)
(Arao and Ishizaka, 1986)
１
3
２
7
4
5
6
9
12
13
14
8 15
18
17
10
11
16
Index map of China with sampling locations
Description of soils of China studied. (Hseung and Jackson, 1952)
Test
no.
Soil type
Parent material
S/A*
Percentage of < 5μ fraction
CaCO3
%
CaSO4
%
Soil
particles
5μ, %
5-2
2 – 0.2
0.2 – 0.08
< 0.08
2
Brown desert soil
Gravel
-
10.2
14.2
2.7
28.0
37.4
26.5
8.1
1
Gray desert soil
Alluvial deposit
-
16.1
0.3
3.3
35.4
11.3
30.2
23.0
5
Chestnut soil
Loess
3.2
12.9
-
27.5
16.2
62.7
14.5
6.6
7
Chernozem
Loess
3.5
3.4
-
20.7
24.6
44.6
26.6
4.3
9
Noncalcic gray brown
Loess
4.0
-
-
20.5
30.6
54.4
12.0
3.1
12
Brown podsolic soil
Quartzitic
Sandstone
2.6
-
-
31.2
24.1
48.2
21.7
6.1
18
Podsol
Chert
4.6
-
-
40.3
34.5
42.2
21.7
1.6
Calcite &
Gypsum
are rich.
A: Desert soil
B: Light colored pedocal
C: Dark colored pedocal
D: Non-calcic soil
E: Podsolic soil
F: Red & yellow earth
G: Latosol
Functional continuity of mineral percentages in various
soil groups in China.
(Hseung and Jackson, 1952)
Yellow dust and reference (aerosol) samples were collected at Nagoya, Japan
by means of two Andersen samplers and analyzed with an X-ray diffractometer.
Mass size distribution of minerals found in the aerosol particles
Yellow dust and reference (aerosol) samples were collected at Nagoya, Japan
by means of two Andersen samplers and analyzed with an X-ray diffractometer.
Mass concentration and their percentage of the principal minerals in the dust
and reference samples
Yellow dust sample during the period
of 14 to 16 April.
Reference sample (aerosol) during the period
of 20 to 26 April.
Mass concentration
(μg/m3)
Mass concentration
(μg/m3)
Percentage
(%)
Percentage
(%)
Quartz
8.1
4.5
1.6
3.2
Feldspar
6.0
3.3
1.2
2.4
Illite
13.1
7.2
2.3
4.6
Chlorite
6.9
3.8
0
0
Kaolinite
7.3
4.0
0
0
Calcite
5.3
2.9
2.9
5.8
Gypsum
6.9
3.8
1.5
3.0
128.4
70.6
40.5
81.0
182 μg/m3
100 %
50 μg/m3
100 %
Others
Total
Main origins of yellow sand dust:
① The desert soils near Taklamakan and Gobi deserts
Illite, calcite and gypsum were abundantly found only in the dust sample.
② The soils in the upper drainage basin of Yellow River
The relative weight fraction of kaolinite and illite in the dust samples were
0.3 to 0.5.
Movement of dust clouds and main origins of yellow sand dust
inferred from their clay mineral composition (Ishizaka and Ono, 1982)
KOSA particles coated with water solution.
(Iwasaki et al., 1988)
EDX and morphological features for the dust particles
Number frequency of elements found in
Individual Asian dust-storm particles.
Nagasaki, Japan.
Okada et al.(1990)
The dust particles collected at Nagasaki, Japan were present as mixed
particles with water-soluble material mainly containing Ca and S.
(Zhang and Iwasaka, 1999)
Samples: Yellow dust particles collected in Beijing under the northwest wind with
the speed of 10 m/s in spring of 1996.
Experiment
・Reagent thin-film test: Most of yellow dust particles did not reach with nitronbarium chloride multiple film.
・EDX analysis: Sulfur was hardly detected in yellow dust particles with the Energy
dispersive X-ray analyzer.
Result
Almost no sulfate is formed and nitrate is hardly formed on the surface of
dust particles during their transport from source regions to Beijing.
Interaction Between Yellow Dust Particles and
Air Pollutants
Far from industry
o
o o
o
o
o
o
o
o
o
oo
o
o
Pure Dust
Particles
o
o
o
o
o
o
Desert Area
o
Industrial Area
Dust Particles internally mixed
with sulfate and/or nitrate