Exploiting Synergies Between Ocean Wind-Wave Modeling and Satellite Altimetry
- (University of New Hampshire)
Ocean satellite altimetry is best known for its measurement of the sea surface dynamic topography, but accurate and high-resolution altimeter observations of ocean wind and sea state are also playing a fundamental and increasing role in global ocean observing system efforts. This project focuses on application of wind and wave data from both satellite altimetry and ocean wave modeling to address new science in both areas of research. In the case of ocean wave modeling, we will focus on the use of global altimetry to guide refined physical and numerical modeling of wave dissipation a topic that is especially critical to more precise wave model prediction in the domain of large-scale breaking waves, and an area where altimetry provides one of few global datasets with unambiguous sea surface data. Our approach will enfold altimeter wave height and radar backscatter measurements along with microwave radiometer and wave buoy data to develop a rigorous ocean surface mean square slope product for use in wave model calibration and verification. For altimeter improvements, this team has demonstrated that data from an operational global wave model hindcast can be combined with altimeter wind and wave data to produce a markedly improved altimeter sea state bias correction. This correction is a necessary and crucial component for accurate altimetric dynamic topography measurements. Goals for a next-generation altimeter sea state bias model include development of a best-case model for the Jason series altimeters where recently enhanced wave model physics are included and where the algorithm development will encompass the long-term altimeter data record from 1993 thru to the Jason-3 period. One important addition to the altimeter constellation in 2012 will be the Ka-band altimeter of AltiKa on the SARAL mission. Data from this higher frequency and lower range noise radar should yield valuable new information related to both the sea state bias and wave modeling activities proposed here, and we intend to develop and analyze Jason-2 and AltiKa crossover measurement datasets to assess predicted and actual impacts. This project should yield significant benefit to the continued improvement of the long-term altimeter sea surface height measurements of the Jason series altimeters by advancements in the sea state bias correction. Moreover efforts will ensure that altimetry continues to support improved global ocean wave model prediction skill through proposed activities tied to an ongoing National Ocean Data Partnership effort directed at fundamental enhancements to wind-wave modeling.