# Designing and Implementing Weather Generators as Web Services
## 5 Summary and Discussion  
The web service framework proposed in this research is novel as it extends usability of weather generators to researchers over the Internet. The responses of the services also provide certain level of traceability information and how the weather realizations were generated. Researchers from a small team without capacity to operate their own weather generator model can utilize these services and focus on their business logic for solving specific problems. The framework ensures interoperability of the service and data using SOS and O & M documents as well as proposing sharing mechanism for identical weather realizations. Legacy weather generator programs are wrapped into RESTful web service. The complicated structure of weather generator model is hidden behind the framework. The procedure for running weather generators becomes simpler by HTTP. Users do not need to handle complicated structure of input file format. Users only need to know the service endpoint and parameters to generate weather realizations. Users' role is clearly separated between model providers, service providers, and general users who only want to get the result from the model. The time for manual data preparation can be dramatically reduced by utilizing the data preparation service. Climatological data source, HW SOS, data transformation service and weather generator model are seamlessly wired. Long-term climatological data, the essential input of weather generator, is passed to the models using concatenation mechanism. It is convenient for users to pass data to the model without downloading and uploading data back and forth across server and a local machine. Gridded climatological data become increasingly available at various scales. Connecting gridded climatological data to weather generator web service can contribute for analyzing the impact of climate changes or risk assessment on every area such as remote farmland in rural areas without weather stations. Weather generator services are implemented in compliance with SOS standard. Any climatological data sources which provide data in SOS format can be directly connected for generating weather realizations [6] implemented SOS API for acquiring gridded climatological data from National Agriculture and Food Research Organization (NARO) which provides gridded climatological data for the whole of Japan [41]. The weather generator services can directly accept response of getObservation from the data source, which is long-term climatological data, as input for generating weather realizations. Even at global scale, climatological data can be connected to the web service framework. For instance, global climatological data from aWhere Inc. [42] in Broomfield, CO, USA, which provides weather over a billion points across the globe, can be a good alternative weather data for data scarce areas such as Africa. The mechanism for connecting to data sources that provide proprietary output can be implemented without effect to the framework. The WSc SOS and IWG are designed for sharing purposes wherein weather realizations are encoded in SOS format. In the current development, we provided these sharing services only for weather realizations generated from normal seasonal forecast (33, 34, 33) because it is fixed; for other forecast probabilities, there are infinite possible combinations of BN-NN-AN, so the weather realizations are provided upon service. Performance of SOS database and InsertObservation operation can an issue in handling numerous weather realizations. For instance, inserting a hundred of weather realizations to SOS database using InsertObservation operation requires about 20 min in our system. Our system is designed to return the result without waiting for the completion of insertObservation, however, it may become a problem when operator frequently updates the cached data or handles huge number of historical weather data. A mechanism for storing and sharing weather realizations from various seasonal forecast scenarios needs to be investigated.