Winter/Spring 2007

Coastal Flooding and Climate Change:
Dynamics versus Statistics

Keith Thompson

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, January 11, 2007

NOTE: Special Day and time

The Juan de Fuca Eddy: How Is It Generated And Why Is It Important

Mike Foreman

IOS Pat Bay

2:30 p.m., Wednesday, January 17, 2007

Wave field evolution in a coastal bay

Ryan Mulligan

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, January 25, 2007

The Upper Ocean Response of the Western Caribbean Sea to Hurricane Mitch in 1998: A Case Study Using SeaWiFS Remote Sensing Data and a Nested-Grid Numerical Model

Jinyu Sheng

Department of Oceangraphy
Dalhousie University

4:30 p.m., Thursday, February 1, 2007

Lateral Momentum Transfer in Juan de Fuca Strait

Keir Colbo

Department of Oceangraphy
Dalhousie University

4:30 p.m., Thursday, February 8, 2007

Maritime Environmental Awareness at DRDC Atlantic

John Osler

DRDC Atlantic

4:30 p.m., Thursday, February 15, 2007

Abstract: The Maritime Environmental Awareness (MEA) Group, and its predecessors at DRDC Atlantic, have been concerned with understanding the impact of the underwater environment on sound propagation and reverberation in order to predict the performance of naval sonar systems. This includes but is not limited to measurement and modelling of: oceanography; marine geology/geophysics; ambient noise; and the roughness of the sea surface and seabed. To support the increasing emphasis on joint (air, navy, land) operations in the Canadian Forces, the mandate of the MEA group is broadening to include the impact of the environment on "littoral operations", including components that are above water, on the surface, and underwater. Accordingly, DRDC Atlantic has a renewed interest in coastal oceanography and meteorology, remote sensing, numerical models to forecast conditions, techniques to assimilate in situ data, and technologies to disseminate, visualize, and integrate environmental information. This talk will present some of the past, present, and proposed research at DRDC Atlantic, with an emphasis on the aspects that involve physical oceanography.

Marine wind analysis with the benefit of Radarsat-1 synthetic aperture radar data

Rick Danielson

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, February 22, 2007

Abstract: A nonlinear regression approach is employed to assess improvements in operational surface marine wind forecasts when synthetic aperture radar (SAR) measurements are also available. As scatterometers have shown, there are benefits to constraining surface wind estimates using space-based observations. However, the benefit of high-resolution SAR measurements comes at the price of ambiguity in wind direction (that is even more severe than for scatterometers). A recent technique to extract directional information is available, however, in the "local gradient" approach of Koch. Lunenburg Bay acquisitions are first employed to test the potential benefit of this technique. Analyses are then constructed for coastal regions of eastern and western North America using a 2D-variational cost function, which simultaneously minimizes differences between the analyses and both wind forecasts and SAR measurements. The error covariance matrices that define the cost function are tuned using an independent set of buoy observations, which permit improvements in the resulting wind fields to be gauged.

Cross Ripples and Wave Direction

Richard Cheel

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, March 1, 2007

No seminar this week

Thursday, March 8, 2007

The Vertical Structure of Low Frequency Wave Motions in the Nearshore

Tony Bowen

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, March 15, 2007

Directional wave measurements from subsurface buoys - an oceanographic and engineering experiment in Lunenburg Bay

Eric Siegel

Nortek USA

4:30 p.m., Thursday, March 22, 2007

No seminar this week

Thursday, March 29, 2007

Applications of a semi-diagnostic model of the Northwest Atlantic Ocean

Xiaoming Zhai

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, April 5, 2007

No seminar this week

Thursday, April 12, 2007

Seismic Oceanography: the new "funtier"?

Barry Ruddick

Department of Oceanography
Dalhousie University

4:30 p.m., Thursday, April 19, 2007

No seminar this week

Thursday, April 26, 2007

No seminar this week

Thursday, May 3, 2007

Turbulence measurements in the coastal ocean using particle image velocimetry (PIV)

Luksa Luznik

Department of Mechanical Engineering
The Johns Hopkins University

4:30 p.m., Thursday, May 10, 2007

Abstract: Increases in human population in the coastal areas and the accompanying increase in pollution and depletion of marine natural resources imposes significant demands on the ocean environment. In this respect, understanding and proper representation of the flow dynamics including turbulence generation and transport in the coastal bottom boundary layer is of considerable interest. This talk will discuss structure and scaling of turbulence parameters in the tidally driven bottom boundary layer on the continental shelf using data obtained from two separate field deployments on the US eastern seaboard with a submersible PIV system. Data are used to deduce, among others, mean velocity profiles, distribution of directly calculated Reynolds stresses, dissipation and production rates of turbulent kinetic energy (TKE) as well as spatial (wavenumber) energy spectra. In addition I will present ongoing research that includes conditional sampling of Reynolds stresses based on instantaneous wave phase using Hilbert transform. Preliminary data indicate that turbulent stresses are modulated by the surface gravity waves, and consequently, wave dependent turbulent production and transport may play a role in the TKE budget.

No seminar this week

Thursday, May 17, 2007

No seminar this week

Thursday, May 24, 2007

No seminar this week

Thursday, May 31, 2007

No seminar this week

Thursday, June 7, 2007

No seminar this week

Thursday, June 14, 2007

No seminar this week

Thursday, June 21, 2007

Observations and simulations of nonhydrostatic internal waves and turbulence in the Saguenay Fjord

Daniel Bourgault and David Janes

Department of Physics and Physical Oceanography
Memorial University

4:00 p.m., Monday, June 25, 2007

Abstract: This will be a joint seminar. Bourgault will present ADCP and microstructure measurements collected through a series of small- and large-amplitude nonhydrostatic internal wavetrains observed near a sill in the Saguenay Fjord. Janes will present results of nonhydrostatic numerical simulations in order to better understand proceses of waves generation and propagation around this sill.