JCSDA Observing System Assessment Standing Capability Development (JOSASC)

The Joint Center for Satellite Data Assimilation (JCSDA) is focusing on the impact of operational satellite data impact in numerical weather prediction (NWP) models. One of its latest efforts is the development of the JCSDA Observation System Assessment Standing Capability (aka. JOSASC). By using this “on-demand” capability, observing system experiments (OSEs) are conducted to assess and quantify the impact of existing satellite instruments on operational NWP systems. The typical design of an OSE is to study the improvement of forecast skill between a control (with the assimilation of all existing observations) and a sensitivity experiment (without the assimilation of the investigated instrument). In order to obtain significant results, the infrastructure will be coupled to an Ensemble Data Assimilation (EDA). 

In this study, we present the preliminary work needed to implement such a robust infrastructure to provide significant results for future instruments deciders, starting with the global GFS/GDAS global and emphasizing tropical cyclones.

This works aims to answer two major scientific questions: 1) How much spin-up is needed to remove the influence of an observation from the control analysis? 2) How can we calculate statistically significant results for a single case study with very limited number of realization?