Accession Number:

ADA556973

Title:

Lagrangian Transport Signatures in Models and Observations

Descriptive Note:

Annual rept.

Corporate Author:

DELAWARE UNIV NEWARK COLL OF EARTH OCEAN AND ENVIRONMENT

Report Date:

2011-09-30

Pagination or Media Count:

12.0

Abstract:

Within the overall objective of identifying and comparing Lagrangian transport signatures in models and observations, we are primarily interested in two aspects of the problem 1 What do Lagrangian features tell us about mixing processes across eddy boundaries and fronts and 2 What is the predictability of these features and the underlying transport patterns Building on our work from FY10, we have quantified the fluid exchange between one particular eddy, the Loop Current Ring Fourchon, and its environment from model data over the course of the eddys life. We also have made much progress on the second aspect of the problem, due to the wealth of observations and model data that became available in connection with the clean-up of the Deepwater Horizon oil spill in the Gulf of Mexico in the spring of 2010. In FY11, we followed two lines of inquiry 1 Lagrangian aspects of mixing across eddy boundaries, and 2 Lagrangian forecasts for oil spill evolution. Under the first theme, we implemented and compared two eddy boundary detection algorithms at depth based on geopotential height contours and nearly closed instantaneous streamlines studied the structure of eddies at depth quantified area and vorticity changes for the LCR Fourchon over the course of its life 157 days and quantified the fluid exchange at the surface between Fourchon and its environment. Under the second theme, we generated oil spill forecasts based on GOM-HYCOM and initialized with observations of the surface slick from two separate sources developed two complementary metrics to evaluate the quality of oil spill surface movement forecasts against observations evaluated the following potential error sources windage effects, unspecified continuous leakage, and initialization uncertainty and investigated the usefulness of Lagrangian coherent structures in the context of oil spill forecasts.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Numerical Mathematics
  • Fluid Mechanics
  • Water Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE