Naval Research Laboratory global model adaptive observing during T-PARC/TCS-08

In support of the THORPEX Pacific Asian Regional Campaign (T-PARC) and the ONR Tropical Cyclone Structure-08 experiments, large-scale adaptive observing guidance for tropical cyclones was provided by the Naval Research Laboratory twice daily using singular vectors (SVs) from the Navy Operational Global Atmospheric Prediction System (NOGAPS). These SVs were calculated for both fixed and flow-dependent regions, providing adaptive observing guidance for tropical cyclones from genesis to recuvature and extratropical transition. The characteristics of the NOGAPS SVs, such as preferred altitudes and the relative importance of wind field to temperature field sensitivity, will be summarized, and the implications for observing system design will be discussed. The relationship of the SVs to synoptic-scale features in the steering flow will be illustrated. Data-denial experiments will be conducted using the NRL Atmospheric Variational Data Assimilation System – Accelerated Representer (NAVDAS-AR) to study the impact of the special T-PARC/TCS08 dropsondes, driftsondes, and rapid-scan satellite winds on the NOGAPS forecasts. Attention will be focused on both the impact on the forecast of the TC itself and the subsequent downstream impacts, especially during periods of extratropical transition.