Satenite cー。ud ーnf。rmati。n chart* 一…AdVanCed TBB 助nt。ur

SatelliteCloud Information
Advanced
Chart*
Tbb Contour
Toshihiro
Chart―
Motoki**
Abstract
Advanced
chart and
Tub contour chart is a new
the
Tub
contour
product improved
There
are two
automatically and/or
The
45
area chart and Asian and Pacific (AP)
Pacicfic area, which
are called
area chart respectively.
FE area chart designed to support the local fieldforecaster is disseminated
minutes
chart
manmachine
kinds of products; one covers Far East area including Japan
and its contiguous seas, and the other Asian and Western
Far East (FE)
the present nephanalysis
chart, and are disseminated in quasi-real-time. This
will contain the cloud area information which are added
interactively.
from
after the 3-hourly map
time
to JMA
(Japan Meteorological
within
Agency)
local
stations by using land line.
The
AP
area chart designed to support the aviation field forecaster is disseminated
within 50 minutes after the 3-hourly map
equater
to 60 N
and 90 E
stations of JMA
to 170 W.
time.
The analysis area covers the area of the
This product will be disseminated to local aviation
bv usins land line.
1. Introduction
After
is to be
the replacement
system in MSC,
of the computer
map
time.
Fig. 3
discontinued, and
area (AP
they will be replaced by
product which
Advanced
is tentatively called
TBB contour Chart (ATC).
are two kinds of samples.
uct produced
with
the
system and IR imagery
1 and Fig. 2.
Sample
with the new
computer
agery are shown
The
system
ATC
these
Chart
(VJ)
** System
and
computer
Far
Engineering
now
These
2.
3-hourly map
time.
Refinement
underway,
of
and
in
computer
system
are
underway.
Vicinty
Processing
Basic data
set for ATC
of physical parameters
is "grid point
extracted from
0.25 lat. X0.25 long. box.
Satellite
of
Data
cloud data set" which contains several kinds
area chart) and
Chart
Pacific
area chart) and is to be sent avia-
to adjust to the new
in Fig. 1
are to be called
Eart
shown in
Western
and IR im-
shown
Chart:
and
parallel with this, also software conversion
in Fig.
area including Japan
charts
Information
type of ATC
covers Asian
these products is now
of product produced
and its contiguous seas (FE
Cloud
every
to support operational
covers Far East (FE)
* Recently
There
Fig. 3 and Fig. 4.
charts are designed
forecasting.
current
Another
every 3-hourly
tion forecasters after about 50 minutes from
Prototype prod-
are shown
to local forecasters
after about 45 minutes from
current product of Nephan-
alysis Chart and TBB Contour Chart will be
a new
disseminated
parameters
Japan
are, for example,
indication, mean
(FE).
TBB,
mean
The
each
physical
cloudy/open
albedo, cloud
top TBB, totalcloud amount, low level cloud
Division.
21
-
METEOROLOGICAL
Fig. 1
An
example
SATELLITE
of the Advanced
CENTER
TECHNICAL
NOTE
Nal5 MARCH
TBB Contour Chart for the Far East (FE)
1987
area.
Observation
time is 0600Z 02 September 1985. TBB
contour interval is 10 degrees from -10°C to -50°C.
Contour lines of ―10°C and ―30°C are presented by thick full line, and those of -20°C and
―40°C by thin full line. Areas surrounded by tick mark lines are those colder than ―50°C.
Categorized cloud top levels are presented by the shading with thin short line, thin long line,
thick short line, and oblique line.
Minimum/maximum
TBBs
within
contours
are shown
in
numerics. Grid point TBBs in the cloud area without contours are also presented by numerics
with equal interval. Letters A, B, and C indicate the developing/decaying features of cloud
systems. Cloud shapes and cloud line/streaks in the significant cloud portions are indicated by
several kinds of symbols.
Fog areas which are detected by man-machine
interaction are presented by the dashed line.
amount,
high level cloud amount,
etc. They
are calculated from the basic histogram
set which is propared in the primary
data
processing system
and
from
GMS
image
taken 24 hours before. In short, ATCs
image
produced
referring to num-
erical predicted atmospheric
information
face temperatures
data
from
data
are
the grid point cloud data set
and sent to users via land line.
vertical profile
Among
objectively estimated sur-
those parameters,
top Tnn and cloud amounts
22
-
mainly
cloud
are used.
The
^UfeffiM-fcv*-
-3
IR
05
6
Fig. 2
latter are
cloud
transformed
into
top levels" according
cloud top level of the box.
BiWM'B
^15-f-
1987^
3 j!
SEP
The
picture of 06Z 02 Sep. 1986 (IR).
"categorized
formation described just above, using various
to dominant
kinds of symbols which denote, for example,
The
categorized
cloud type, cloud line, cloud streak, vortex
cloud top level represents horizontal cloud
center, cloud system
top level represents horizontal cloud distri-
identification,etc. As to developing or de-
butions, in contrast with that the cloud top
caying features of cloud systems, letters A
T,in represents
through
clouds.
vertical
development
of
Cloud distribution pattern is visua-
lized by means
TB/i contour lines and
shaded
tion by means
man-machine
of Image
of cloud top height and cloud extent
are used.
3. Categorized
area charts, results of pic-
ture analysis through
as to temporal
maximum
TBR values for notable clouds.
In case of FE
are used, and
Cb or Ci
of cloud portions, letters x, y, z, u, v and w
patterns of
categorized cloud top levels, and
or minimum
change
of combination of cloud top
E
movement,
Threshold
interac-
red
Processing Console
in
amounts
are added to the automatically produced in-
LI:
23
-
the
Cloud Top
Level
temperature levels to be refercalculation of
partial cloud
are selected as follows;
surface temperature
minus TTA
METEOROLOGICAL
SATELLITE
CENTER
TECHNICAL
NOTE
No.15 MARCH
1987
Fig. 3 An example of the Advanced TBB Contour Chart for Asian and Western Pacific(AP)
area. Observation time is 0300Z 07 May 1986. TBB contour intervalsare 30 degrees from
―10°Cto ―70°C.Categorized cloud top levels are given by the same shaded patterns as
shown in Fig. 1. Minimum TBB are presented on each Most-high level cloud area.
L2 :
700 mb
temperature
L3 :
400 mb
temperaturs
L4:
where
･Partial cloud amount
and TTB
Middle level cloud area ;
are bias values, and
Ci-level TBB is described afterwards.
shold levels are determined
The
Partial cloud amount
Thre-
for each
box, and partial cloud amounts
lated referring to them.
where
are calcu-
total cloud amount
is greater than
this category.
High level-cloud area;
as des-
Partial cloud amount
cribed below,
Low
L2 and L3 is
or equal to 80 percent are also regarded as
categorized
partial cloud amount,
between
greater than or equal to 80 percent. Boxes
grid
cloud top levels are determined according to
the dominant
LI and L2 is
greater than or equal to 50 percent.
Ci-level TBB minus TTB
TTA
between
above
than or equal to 80 percent.
L3 is greater
level cloud area:
Most-hight level cloud area ;
24
-
&feffiS-fev*bTlS-3
IR
0 231
^^^^V
JKW
8b
- ^
mPY
07
-<･
:tr^^
tf,.■ -
Figr.4
Same
as the case of high
&WM^
The
H15^
03Z
'
level cloud area
than
data, data, which
MSC
were
values.
day
used
For
mean
are
currently used
to obtain
sea surface
surface TBB
the
data
which
area was
The
L4 level TBB
were
tion
case
high level was
level according
study
made
by
(1983).
more
easy
may
threshold
was
of IR
cold
to
threshold value is given and a
25
-
data
TBB
location
have
Cb
is
the
is empiri-
minus
15° and
is
categoriza-
the Most-high
in
level
view
oi
con-
cloud
areg
of forecasters.
very
important
there
Cb
only.
which
area
Then
of
of atmospheric
however
analysis
area
value
introduced
difficulties in identifying
have no climatic or reliable value for Ci-
box.
TBB
level
Most-high
local forecasters,
We
cloud
recognition
area
colder
is set 4 degree.
of
call the attention
Cb
data
mode
development,
top level
level TBB decision algorithm as follows.
First, a
the
temperature
algorithm
cloud
set around
to the results of a
Motoki
The
ditions, because
separates Most-
TBB
value for each
set
In the process
for low level cloud
which
from
the bias temperature
10-
set 3 degree from results of tests.
high level from
250 mb
TTA
is
cally set 400 mb
prepared for the testsruns were used. The
bias temperature,
made
the threshold
histogram.
in
threshold
temperatures
is
Ci-level TBB
(GMSSA)
^^^^1
1986 (IR).
histogram
In test runs, climatic vertical temperature
Standard Atmosphere
.asm. t**>*JHWVv ^VL^Lk!
picture of 03Z May
but its cloud top TBB is colder than L4.
profiles,GMS
1987^ 3 j!
has
area
foi
are
by
som(
mean:
So in ATC,
high
identified
verj
probability
simply
a;
METEOROLOGICAL
Most-high
SATELLITE
CENTER
TECHNICAL
level cloud area; for example,
NOTE
No.15MARCH
1987
chart will be increased when
it is used in
high brightness areas in Fig. 2 and Fig. 4
combination with digitalradar data and/or
are
rainfall data of densely distributedrain
gauges from Automatic MeteorologicalData
mostly
identified as
cloud area in FEA
Most-high
and AP
level
chart. In FEA
charts Cb/Ci identification is to be added
man-machind
Occurrence
long
AcquisitionSystem (AMeDAS)
of JMA.
interactively.
of dense
Ci coverage
Acknowledgement
having
The author wishes to express his appre-
life-time is also useful information.
For example, anticyclonic expansion of dense
ciationto Mr. H. Hasegawa, Meteorological
Ci coverage is often observed before or dur-
SatelliteCenter, for reviewing the manu-
ing rapid development
script and
nHvire
turbances.
age
We
of extratropical dis-
believe that dense Ci cover-
lasting long
newly
seminated
developed
ATC
References
will be dis-
Motoki, T., 1983: Temporal change of toperingshaped cloud area observed by GMS. Tenki,
30, 565-569 (in Japanese).
3-hourly, and give users informa-
tion about the temporal change
subsynoptic
of synoptic/
systems, and usefulness of the
(Editor's note:
Manuscript
submitted in the CGMS
received 30 November
1986.
This report was
meeting held in New-Delhi, India, November
1986.)
SH≪1t*REIU:-?^T
7C
%f6&M.-*v
^T-f^ssc^^,
are
time is closely related to
the activity of jet stream.
The
giving useful comments
^≪^*h-/wgi
(i/25oo^)
7fC
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i&
-y^T-^mM
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26
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