200 - Typhoon Committee

ESCAP/WMO
Typhoon Committee Annual Review 2007
c. Interaction with Users, Other Members
and/or Other Components
There are no updates this year.
d. Training Progress
d.1 Seventh Typhoon Committee training seminar
JMA, which is in charge of the Regional Specialized
Meteorological Centre for tropical cyclones within the
framework of the WMO (through the RSMC Tokyo -
Typhoon Center), assists Typhoon Committee (TYC)
Members in the improvement of typhoon monitoring
through the provision of typhoon analysis/forecast
products and the implementation of typhoon analysis/
forecast training.
As part of these activities, the Center has conducted
an annual TYC Training Seminar at JMA headquarters
in agreement with the TYC since 2001. In 2007, the
seventh seminar was held from 18 to 27 July with the
participation of two female forecasters from Cambodia
and the Philippines. In the seminar, they received onthe-job
training in typhoon analysis using the SATAID
software developed by JMA, and attended lectures on
typhoon analysis/forecasting as well as the typhoonrelated
operations of JMA.
As no tropical cyclone formed for tracking during the
seminar, the forecasters tackled the Dvorak analysis
using previous satellite images of tropical cyclones
including MAN-YI (0704).
Figure 4 Seventh Typhoon Committee training seminar
d.2 Group training course in meteorology
JMA has conducted group training courses in
meteorology since 1973, and the course was renewed
in 2003. The current training course focuses on the
utilization of satellite data including neph-analysis, and
the application of numerical weather predictions and
climate information/data. In September 2007, the threemonth
course for the year started with eight participants
from eight countries, including Thailand from among
the TC member countries.
d.3 Dispatch of an expert to the roving seminar
In September 2007, JMA dispatched an expert to the
roving seminar held in Manila to lecture on the topic
of The Interaction of Tropical Cyclones with Monsoon
Systems.
d.4 Technical cooperation
Since July 2006, Japan has implemented a technical
cooperation project in Lao PDR with a view to developing
human resources on meteorology and hydrology
through the Japan International Cooperation Agency
(JICA). The project is scheduled for continuation until
the beginning of 2010.
An expert dispatched in December 2006 by JICA to the
Department of Meteorology in Cambodia continues to
be engaged in the rehabilitation/improvement of civil
aviation meteorology in the country. The expert is
scheduled to be in Cambodia until early next year.
e. Research Progress
e.1 Improvement of the initialization scheme for tropical
cyclones
JMA has confirmed an improvement in numerical
tropical cyclone (TC) track prediction as a result of
modifying the operational initialization scheme for TCs
(i.e. the Typhoon-Bogus scheme) in the global spectral
model (GSM-TL959L60).
In the Typhoon-Bogus scheme, several “pseudo”
observational data are deployed inside a circle around
the observed center position of the TC. These data are
taken into account in the 4D-VAR global data assimilation
process. The radius of the circle is called the Bogus-
Radius. While this value for each TC of Tropical Storm
(TS) intensity or higher is specified with a function of
the radius of 30 kt winds and the Coriolis parameter
at the center of the TC, a fixed radius of 360 km has
been used as the Bogus-Radius for tropical depressions
(TDs), since TDs have no analysis of the 30 kt wind
radius.
However, the fixed Bogus-Radius for TDs has occasionally
worked inadequately and failed in appropriately
correcting erroneous TD positions in the first-guess
field. To alleviate the problem, a function has been
introduced to enable variation of the Bogus-Radius
for TDs depending on their strength and latitudinal
location. The newly introduced Bogus-Radius for TDs
is defined as a function of their central pressure and
the latitude of their center position, with a lower limit
36