Presenting Author: Professor Mark Bourassa
Our technique for determining vorticity from scatterometer observations of surface vector winds is revised to be much more versatile and robust. Vorticity is calculated using the circulation, and the area about which we are calculating the circulation. For calculations on the smallest spatial scale, this technique is mathematically equivalent to a finite difference. Biases and random errors are estimate as a function of spatial scale. There are three main sources of error: random observational error, truncation errors related to the assumption of linear changes between wind vectors, and errors associated with mis-matches in spatial scale. The observational component can be well estimated, and is typically small. The truncation error is quite large, particularly for small spatial scales. Spatial scales of greater than or equal 75km (three grid cells) greatly reduces the noise; however, larger spatial scales result in biases. These results are also discussed in the context of desired characteristics of future satellites for measuring ocean surface vector winds with the goal of examining tropical cyclogenesis.
2019 International OVWST Meeting
May 29-31 in Portland, Maine, USA