APL Seminar: "Ocean observing, forecasting, and energy harvesting", Yi Chao (JPL)

Start Date/Time: Thursday, January 21, 2010, 2:30 PM
Location: Hardisty Conference Center

Title: Ocean observing, forecasting, and energy harvesting.
Presenter: Yi Chao, NASA Jet Propulsion Laboratory, Pasadena, CA

Ocean circulation and variability involve multi-scales in both space and time. This talk will describe a hierarchy of nested models resolving both the basin-scale climate variability with a relatively coarse resolution (on the order of 10-km) and coastal regions with a spatial resolution as fine as 1-km. Advanced data assimilation algorithms are developed to integrate observations with model simulations in a statistically optimal but dynamically consistent manner. Ensemble forecasts from multiple models are recently attempted in order to estimate the forecasting error. Preliminary results to integrate the physics/dynamics with biogeochemistry, marine ecosystem and fish will be described. Possibilities to connect the synoptic forecast with the climate prediction (e.g., El Nino) will also be discussed. Like weather forecasting, ocean forecasting is ultimately limited by how well ocean can be measured on the routine basis. While ships and moorings are expensive to operate, unmanned underwater vehicles (UUVs) have to be frequently recovered for battery change/recharging. Prototyping a fundamentally new platform that can be deployed underwater over a long period of time is described. The idea is to extract the local renewable thermal energy in the ocean to power the vehicle completely including buoyancy engine as well as navigation/communication and scientific sensors. We have identified a Phase Change Material (PCM) that can be melted in warm waters and frozen in cold waters. This melting/freezing process can generate a significant volume change and therefore a high-pressure fluid that can drive a hydraulic motor for power generation. Preliminary results from the December 2009 deployment of a prototype thermally powered float will be described and its potential in monitoring long-term ocean and climate change will be discussed.