Analysis Tools for Numerical Simulations of Estuaries Parker MacCready University of Washington NANOOS PI Meeting 2/1/2006 Newport, OR

Motivation The initial scope of my part of the NANOOS Pilot was to develop quality metrics. This is relatively straightforward, and is already being done as part of the CORIE system. => I have put my effort into developing useful metrics that: –(1) We are able to compute because we have the full 3-D fields calculated by the numerical simulations –(2) Give insight into the function of the system

Progress Metrics related to time-dependence (adjustment time and sensitivity) developed (theory, a simple numerical model, and comparison with observations) and submitted to J. Phys. Oceanogr. Metrics related to flow of mechanical energy in the system developed and presented as a talk at ERF Draft write-up of Analysis Tools done in December I am now working with Antonio and his Masters student on implementing them in the CORIE system.

Quasi-steady response of the length of the salt intrusion to varying Q R This is a classical metric, which we know observationally for a number of estuaries It can be distilled into the exponent in a power law relating the length of the salt intrusion to the river flow

Consider the effects of time- dependence Estuaries take time to adjust to their forcing conditions. The ratio of the adjustment time to the forcing timescale can strongly affect whether or not the estuary feels the effects of a given change in forcing Example: Stratification is generally MORE sensitive than you would predict from a quasi-steady theory, whereas the length of the salt intrusion is LESS sensitive.

The Mechanical Energy Budget By evaluating terms in the volume- integrated, tidally- averaged energy budget, we may better understand how an estuary works In this example the long residence time is a consequence of the huge reservoir of potential energy stored in the length of the salt intrusion

Conclusion The advent of realistic 3-D numerical simulations of estuarine circulation and salinity structure (and eventually ecosystems) gives us much greater ability to develop metrics to describe and compare these systems.