OSSEs are a challenge to operational weather services. OSSEs require strong leaders with a clear vision, because many of the efforts offer long-term rather than short-term benefits. Carefully designed OSSEs will enable scientists to make strong and important contributions to the decision making process for future observing systems. Time will be saved in using the new data when compared to the work required to use observing systems that were built without any guidance from OSSEs. However, there is a serious dilemma in spending resources on OSSEs. If operational centers devote its resources to OSSEs, it may not be paying enough attention to today's valuable data.
Although operational systems should benefit from carefully executed OSSEs through lower cost of implementation, there are immediate costs to OSSEs. OSSEs will be conducted by various scientists with different interests. Some will want to promote particular instruments. Others may want to aid in the design of the global observing system. Specific interests may introduce bias into OSSEs but they may also introduce strong motivations. Operational centres will perform the role of finding a balance among conflicting interests to seek an actual improvement in weather predictions, while OSSEs at research communities funded by specific interest. Research community has more freedom to explore the possibility of new observing system. It is best to use operational data assimilation system to make the work relevant to operation (R2O). For that purpose close communication and assistance from operational community is required (O2R). Therefore, OSSE is a very effective tool to bond research and operational communities. Joint Center for Satellite Data assimilation (JCSDA) is one of the best institutes to conduct effective OSSEs to take balance between operation(O) and researches(R).
Recently various OSSEs have been conducted at JCSDA. In this presentation overview of OSSEs accomplished and future plans at JCSDA will be presented. Costly instrument such as Doppler Wind Lidar were evaluated in various configurations. High-resolution hyperspectral sounder, and microwave sounder in Geostational platforms are being evaluated. Effect of additional CPSRO satellites are evaluated with collaboration with NOAA/ESRL. Further OSSEs to evaluate combined effect of these instruments as well as PCW are proposed. OSSEs for Arctic observing system proposed is a challenge to the lack of operational tool over Arctic region.
Finally, experiences with OSSEs demonstrates that they often produce unexpected results. Theoretical predictions of the data impact and theoretical backup of the OSSE results are very important as they provide guidance on what to expect. On the other hand, unexpected OSSE results will stimulate further theoretical investigations. When all efforts come together, OSSEs will help with timely and reliable recommendations for future observing systems