HR: 11:05h
AN: OS52A-04    [Abstracts]
TI: Assimilation of Current Measurements Into a Circulation Model of Lake Michigan
AU: * Zhang, Z
EM: zpzhang@stanfordalumni.org
AF: University of Chicago, CISES 5734 South Ellis Ave, Chicago, IL 60637, United States
AU: Beletsky, D
AF: University of Michigan, CILER, SNRE University of Michigan, Ann Arbor, MI 48105, United States
AU: Schwab, D
AF: NOAA, GLERL, NOAA, Ann Arbor, MI 48105, United States
AU: Stein, M
AF: University of Chicago, Department of Statistics University of Chicago, Chicago, IL 60637, United States
AB: We present a method for assimilating current observations into a two-dimensional circulation model of Lake Michigan, based on the Princeton Ocean Model (POM) and driven by observed winds. Because measurements of surface level are not available, we require that the point-wise update to the forecast horizontal current does not change the forecast surface level. This requirement makes it possible to represent the current updates by a stream function. Given an appropriate covariance model of this stream function, the current updates are calculated by kriging interpolation using the observations and the corresponding model forecast. It is further required that the current updates do not create cross-shore flows; this is represented by the stream function being constant along the coastline and is enforced by incorporating pseudo coastal data into the interpolation. This eliminates the need to construct complex spatial covariance models for the stream function. The method also accommodates observational errors. Results show that the method successfully melds observations into the model, and the influence of data assimilation propagates in space and time.
DE: 3315 Data assimilation
DE: 4239 Limnology (0458, 1845, 4942)
DE: 4255 Numerical modeling (0545, 0560)
DE: 4512 Currents
DE: 4534 Hydrodynamic modeling
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting