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Introduction

The skilled forecasters at the Taiwan Central Weather Bureau are keenly aware that millions of people depend on the accuracy of their predictions, because when they predict the weather, people do listen.

On average a half dozen typhoons hit Taiwan each year, endangering its 21 million residents, flooding its field crops, and polluting its reservoirs, groundwater, rivers, and coastal waters. Taiwan receives more rainfall than any part of the Chinese mainland (ROC 1996). Mostly mountainous terrain (subject to deforestation in the past), Taiwan lies in the track of severe tropical cyclones known in East Asia as typhoons, which produce violent winds and tremendous rainfall.

Although torrential rains can appear almost anytime of the year, typhoons are expected to occur with certain regularity. During the main typhoon season (July, August, and September), some windward mountain slopes can get a foot (~300 mm) or more rainfall within 24 hours. But even this statistic can be dwarfed when compared with rainfall recordings of occasional typhoons, such as Typhoon Herb, the largest typhoon to hit Taiwan in 30 years. Typhoon Herb left a 48-hour rainfall accumulation of 78 inches (1987 mm), recorded at the Central Weather Bureau Alishan weather station. The satellite picture above captures the ubiquitous typhoon as it struck Taiwan on 30 and 31 July 1996, causing 45 fatalities, 23 missing, 450 injured, and billions in damages.

In the winter, the northeast monsoon, accumulating abundant moisture as it crosses the East China Sea, brings heavy rains to the eastern and northern sides of the island (ROC 1996). In northern Taiwan, it can rain for two months at a time, while, ironically, the southwestern region can be plagued with prolonged drought, necessitating irrigation.

In their efforts to mitigate the disastrous effects of ever-threatening flash floods, the government of Taiwan is allocating a larger chunk of its budget and workforce to research and development of new technologies. In 1990, through the American Institute in Taiwan, it contracted with FSL to help develop forecast systems with accompanying technical support and training. Use of turnkey computer systems during the 1980s proved unsatisfactory to meteorologists and management at the Taiwan Central Weather Bureau. They needed scalable computer systems that could be tailored to readily meet their specific forecasting and warning needs.



Figure 1. A Japanese Geosynchronous Meteorological Satellite photograph of the largest typhoon to devastate Taiwan in 30 years. On 30 and 31 July 1996 Typhoon Herb struck Taiwan (center) causing 45 human fatalities, 23 missing, 450 injured, and $2.5 billion in damages.

The First Five Years: 1990 - 1995

The Joint Forecast Systems Project between the Central Weather Bureau and FSL became official after formal negotiations were ratified with a 5-year general Agreement for Cooperation through the Taipei Economic and Cultural Representative Office and the American Institute of Taiwan. The collaborative goal to revamp the Central Weather Bureau with the most advanced systems and to train forecasters so that they would have a global understanding of the systems would ultimately place the focus on the 0 to 24-hour forecast.

Technology transfer offers many opportunities to both the beneficiary and the provider. Over the last six years, the cooperative research and development activities included:

• Meteorological workstation development, with system and software design and documentation, and advice and support for upgrades.

• Adaptation of FSL developments to a diverse forecasting environment.

• Onsite technical support and training at both the Central Weather Bureau and at FSL.

Here, we discuss these and other activities to date, as well as future plans. (An earlier article on this project was published in the July 1992 issue of the FSL Forum. )

During the initial phase of the project, a PC-based forecast workstation was jointly developed, and then combined with the Central Weather Bureau's existing central facility, which included data sources, communication, preprocessing, and product generation. The much needed new system, called the Weather Information and Nowcasting System (WINS), became operational six months ahead of schedule and was dedicated in April 1992. The Central Weather Bureau National Forecast Center, patterned after FSL's, comprises five operational workstations and two development workstations.

From the outset, probably one of the most important objectives was to design a system that could integrate all data types available for forecaster use at one central location, to be disseminated to other weather stations around the island. Before the installation of WINS, it could take hours to gather information from various data sources. According to a lead forecaster at the Central Weather Bureau before its modernization, Harry Chen, now on assignment at FSL, weather information would arrive piecemeal from other locations around Taiwan. A storm could be closing in, and the forecasters were unable to make an accurate forecast because of the many delays in getting all the data. Weather reports might come from one station right away, while taking minutes or hours longer from others. Consequently, no matter how hard the forecasters worked to beat the clock, it would inevitably take far too long to refine a forecast.

With fundamental data integration technology in place, WINS now displays data from the Central Weather Bureau Numerical Weather Prediction Model and numerous observation systems, data from the European Centre for Medium-Range Forecasting, and satellite imagery from the Japanese geostationary satellite. These data and products are provided to outside users including two universities, the Taiwan Environmental Protection Agency, and the Taiwan Hydrology Bureau.

Project Extension - 1996 to 2001

The general Agreement for Cooperation in meteorology and forecast systems technology through the Taipei Economic and Cultural Representative Office and the American Institute in Taiwan has been extended through June 2001. The Central Weather Bureau and FSL will continue working on areas of mutual interest to assure that the Central Weather Bureau establishes a mature and independent capability to expand upon this science and technology for improving the quality of weather services in Taiwan.

The primary accomplishments during the second phase of the modernization program will:

• Improve the integrated forecast environment and expand forecast products using all available data sources.

• Enhance forecast guidance through evaluation of the relationship between forecast products and local weather elements.

• Improve the radar networking capability to integrate all the data and products from Doppler radars and conventional radars in Taiwan.

• Improve data assimilation techniques for the numerical weather prediction models at the Central Weather Bureau through the use of satellite and other data.

• Improve access and quality of service to data users through the use of public telecommunication services.

• Improve the integrated networking capability for communication and resource sharing with the new CWB building (Figure 2), to be dedicated this month.


Figure 2. The newly completed Central Weather Bureau Forecast Center in Taipei, Taiwan.

CWB-Advanced Workstation

Although the PC-based platform originally placed in the Central Weather Bureau has provided valuable insight into modernized operations, a more powerful and flexible system is needed to accommodate more advanced datasets and products, and to reinforce the forecasters' arsenal of technology to combat potential weather crises.

For the last few years, FSL has been developing and testing a new forecaster workstation system, the Weather Forecast Office Advanced system (WFO-Advanced), which will be part of the national Advanced Weather Interactive Processing System (AWIPS) to be deployed later this decade. The WFO-Advanced system uses a Unix and X environment with a RISC-based architecture and distributed network design, which offers more flexible and reliable upgrades for the Central Weather Bureau's version of this system, CWB-Advanced.

The packed implementation schedule during the remaining years of the project will ensure that all new and improved products are well tested before incorporation into the CWB-Advanced workstation. FSL will provide support in the following areas:

• Data and Product Communication - Includes data acquisition from satellites, the National Weather Service Automated Surface Observing System (ASOS), Doppler Weather Surveillance Radar (WSR-88D), and local data sources.

• Data Management - Includes data storage, access, inventory, purging, and archiving capabilities.

• User Interface and Interactive Display - This function includes interactive graphics display and editing, and user interface menus.

• Local Product Generation - Includes local product generation, decoders and encoders, grid to graph, and depictables.

• Hydrometeorological Applications - Includes application interface protocols so that users can create their own hydrological applications and extensions, especially important to Taiwan.

• Monitoring and Control - Includes data monitoring, process monitoring, system performance monitoring, as well as a restart mechanism.

We discuss in more detail below the implementation of the Open Systems transition, the Forecast Preparation System, and data assimilation at the Central Weather Bureau.

Open Systems Transition - Staff at the Central Weather Bureau are implementing an integrated and Open Systems environment, called the Network Information exChange Environment (NICE), so that their computer facility resources and meteorological data can be shared with a larger array of users. NICE is based on the FSL Central Facility Networked Information Management client-Based User Service (NIMBUS), which provides a data-access and distribution mechanism for Open Systems platforms. The step-by-step conversion process to an Open Systems environment presents many challenges to engineering and management staff alike. FSL will provide technical assistance in the following areas in the completion of the transferal of NIMBUS technology to NICE:

• Information Transport - Provides the interprocess communication mechanism for all real-time processes. Meteorological data and messages are communicated within the IT using Remote Procedure Calls.

• Process Manager - Provides scheduling and control functions that control running applications software under predefined conditions.

• Managed Process - Provides a software application, run under the Process Manager, that is critical to meeting meteorological data requirements.

• Data Format Translation - Homogenizes datasets by converting and decoding the ingest-specific data formats, enabling the datasets to contain similar information. In general, World Meteorological Organization formats will be used.

• Meteorological Database - Data storage software will be provided for public use. FSL has completed the NIMBUS NetCDF generators for different types of data including point data, gridded data, satellite data, and radar data. Use of NetCDF as the input and output format will be quite valuable in the Open Systems development at the Central Weather Bureau.

Forecast Preparation System - FSL and the Techniques Development Laboratory at the National Weather Service headquarters, in Washington, D.C., are working on a graphical forecast support system known as the AWIPS Forecast Preparation System (AFPS). AFPS is to be deployed nationwide around 1998, and will eventually become an integrated part of AWIPS. The anticipated adaptation of AFPS, the Forecast Preparation System, by the Central Weather Bureau will help Taiwan forecasters develop and validate a more efficient and effective method of preparing forecasts. It will provide the interactive graphic editing and text forecast generation capability for analyzing different weather systems. The implementation of Taiwan's Forecast Preparation System will include assistance from FSL on the following activities:

• Forecast Database - Contains the general and service-specific forecast database, as well as forecast-specific products that are needed by the text generator. The desired forecast is saved in the database as the official forecast, and all text forecasts are generated from this database.

• Radar Testing and Calibration - During the installation of new radars, the acceptance tests, including calibration, will be extremely important for the Central Weather Bureau. Radar staff at FSL have WSR-88D operational experience and can provide testing and calibration support.

• Radar Maintenance and Development of New Applications.

• WSR-88D Text Editing - The radar coded message is produced in two stages, a preedit stage and a postedit stage. The preedit stage is produced at the Radar Product Generator (RPG) and designated to the Unit Control Position (UCP) operator for editing. After editing, the postedit version is transmitted back to the RPG for distribution. These messages need to be edited at the Central Weather Bureau, rather than at the UCP. FSL will provide consultation in the design of the radar text editing capability.

Data Assimilation - FSL has developed a high-frequency data assimilation system as part of the real-time Mesoscale Analysis and Prediction System (MAPS), which covers the lower 48 United States. This domain has a relatively dense data coverage. For extension of the MAPS domain beyond its current boundaries, remotely sensed data from satellites will be used. The MAPS development team has performed preliminary testing of methods for directly incorporating satellite radiances into initial conditions for numerical prediction models.

A major upgrade is planned for the Central Weather Bureau data assimilation capabilities. Use of improved analysis techniques are needed to improve the description of the divergent wind field. FSL will provide support for the following data assimilation activities:

• Radiance Data Processing - FSL and Central Weather Bureau scientists will develop techniques for processing satellite-observed radiance data, which provides more frequent data from the land and oceans. The radiance data from the NOAA polar orbiting satellites, TIROS (Television and Infrared Operational Satellite) Operational Vertical Sounder (TOVS), will be used to initialize the numerical models at the CWB to increase forecast accuracy. The traditional retrieval technique (of temperature and moisture) resulted in poor data resolution in the vertical direction. The improved techniques being developed are expected to alleviate this deficiency.

• Data Assimilation Techniques for Radiance and Other Data - This includes development of the analysis of radiance increments from satellite data and preparation of ACARS automated aircraft observations data for assimilation experiments. [ACARS is the Aeronautical Radio, Inc. (ARINC) Communications, Addressing and Reporting System.]

• Optimal Interpolation - Most world meteorological centers currently use the optimal interpolation (OI) method of objective analysis of meteorological data. A new correlation model in the optimal interpolation algorithm will be implemented allowing divergence in the analyzed wind. The MAPS model runs a real-time, three-hour data assimilation cycle using an OI scheme as well as a three-dimensional variational analysis (3DVAR) scheme. With an OI analysis scheme, MAPS successfully integrates asynoptic wind information, and eventually will incorporate asynoptic mass information from the TOVS data. For data assimilation at the Central Weather Bureau the use of radiance data in lieu of retrieved temperature data in numerical weather prediction will be tested. After this technique has passed operational tests in the MAPS environment, it can be used with the CWB models.

• Advanced TOVS Data - A data ingest technique for advanced TOVS (ATOVS) data will be developed. The radiances from MAPS fields will be calculated and modified, based on ATOVS radiances, and converted back to MAPS variables. Work will also include testing adjoint-based inversion techniques.

Visitor Exchange Program

Each year three or four visiting scientists come to FSL from the Central Weather Bureau to participate in workstation and central facility development, radar data acquisition, and data assimilation research activities. The stay of each visitor varies from six months to two years. Many of these people make personal sacrifices, leaving family behind, to come here and learn. In 1995, six Taiwan forecasters also participated in the FSL WFO-Advanced forecast evaluation exercise in Boulder. Figure 3 shows two chief forecasters from Taiwan, Messrs. Kuochen Lu and Jiunn Sheng Shang, working at the FSL forecast center.


Figure 3. Chief forecasters Kuochen Lu (right) and Jiunn Sheng Shang from the Taiwan Central Weather Bureau working at the FSL Forecast Center.

These visiting scientists play a significant role in the technology transfer process. They concentrate on specific and global software development of the workstation systems at FSL. Thus when their visits at FSL conclude, they return to the Central Weather Bureau able to customize software there to produce local products and applications needed to improve operations.

The Visitor Exchange Program receives enormous support from different FSL divisions. According to Wayne Fischer, head of the International Program, to date about 40 people from FSL have visited the Central Weather Bureau. "It has been a very beneficial opportunity for staff here to understand about the technical and scientific problems that a weather service like the CWB has to deal with," he says, "as well as being able to get some feeling for the Chinese culture."

Of the many FSL employees who have contributed to this project, Dr. Fischer says a few people stand out as major contributors to the success of the project. FSL Director Sandy MacDonald was the catalyst during the negotiating stage and continues to play a significant role in the project. Herbert Grote, head of the Systems Development Division, served as the technical manager during the initial PC workstation development. Glenda Wahl, a project leader from the Facility Division, played a key role in the initial system planning. Bob Lipschutz, a systems analyst, and Frank Pratte, an electronics engineer, also from the Facility Division, have been asked again and again to return to Taiwan because of their expertise in Doppler radar and their willingness to help. Carl Bullock, a supervisory meteorologist from the Modernization Division, has visited there twice to work with the forecast staff from a forecaster's point of view. Bullock delighted about 20 forecasters on his first visit, says Fischer, when, after only a short briefing, he was able to turn the operation of the workstation over to the Director General of the Central Weather Bureau, Mr. Shinn-Liang Shieh, who had not been an active forecaster for many years. Darien Davis, a computer specialist from the Modernization Division, is also lauded for her ability to consistently work closely with visiting scientists from Taiwan on workstation development. "She has done a remarkable job at being able to understand their skills and interests and finding the best niche at FSL for them to learn a great deal and also to be able to contribute to FSL's work," says Fischer.

In addition, specialists from the following FSL divisions have provided technical expertise: Forecast Research Division in achieving data assimilation tasks; the Facility Division in the Open Systems development; the Modernization Division and the Systems Development Division in the workstation management and development; the Demonstration Division regarding the selection of locations for a wind profiler network in Taiwan.

This interaction is an excellent two-way learning experience. Two project review meetings are scheduled each year, one in Boulder in October and one in Taipei in March. FSL staff are also invited to participate in forecast exercises, international conferences, and workshops sponsored by the Central Weather Bureau, Taiwan universities, and the Taiwan Meteorological Society.

Summary

The beginning of this decade was a very opportune time to pursue workstation development in Taiwan, comments Fischer, because they recognized that it was important to their continued economic development to improve forecasting capabilities. Moreover, Dr. Ching-Yen Tsay, the Director General of the Central Weather Bureau when our cooperation began, and Mr. Shinn Liang Shieh, the present Director General, have been very receptive to new ideas and provided FSL with the opportunity to work with a bright young staff who were reassured that government from many levels wanted to improve Taiwan's forecast capabilities. FSL in turn assigned experts to the many tasks at hand to make this project successful.

On a smaller scale, the Central Weather Bureau is very much like the National Weather Service in that they have the same functions and the same responsibilities, and they have the same issues facing them as to the direction of how their weather services will continue to evolve. Our role with them changes as their sense of their future direction changes. There have been efforts involving the workstation and Doppler radar that have continued, and there are new joint efforts in data assimilation and visualization techniques. The CWB leaders realized that FSL's proposed PC version of the FX-Advanced workstation would fit their forecasting requirements.

FSL developers have learned that they have to be able to try a variety of technology transfer activities, and they have learned a lot about how to move something from laboratory development to operational use. Accomplishing this in an organization the size of the Central Weather Bureau has made it easier to determine what works, and has been a real learning "tool" as well. This project has also provided a unique opportunity to address organization-wide issues.

In ranking weather service organizations around the world, Dr. Fischer believes that Taiwan has moved from a third-level to a top-level agency, with special skills in forecasting typhoons.

Reference

The Republic of China Yearbook, 1996. Published by the Government Information Office, Republic of China.

(Fanthune Moeng, the Central Weather Bureau Project Coordinator, has worked at FSL since the inception of this project. Wayne Fischer, head of the International Program, credits much of the success of the project to Dr. Moeng, through his understanding of Taiwan's forecast problems and his ability to keep the communication links open, his dedication in helping visitors from Taiwan overcome the cultural hurdles here, and his incomparable professional abilities.)