Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Dye Experiment Study of Cross-Frontal Exchange, R/V Oceanus Cruise 342
DMO notes:
The documentation below describes a two ship operation. The data reported here are from the Bob Houghton cruise on the Oceanus 342.

PI documentation:
Two cruises were undertaken in May and June 1999 in which dye patches were released to study cross-frontal exchange. On Oceanus Cruise 342, led by Bob Houghton of LDEO, dye was released in the bottom mixed layer. A Scanfish towed unit was used to moniter the dispersion of dye as well as locate the frontal system on the Southern flank of Georges Bank. Jim Ledwell and Jim Churchill of WHOI led Endeavor Cruise 323/324 in which dye and drifters were deployed in the pycnocline and in the surface layer. Sampling on this cruise was done by the WHOI VPR group, yielding plankton distributions.

Figure 1 shows the location of dye and drifter deployments during these cruises. The LDEO dye was Fluorescein injected into the bottom mixed layer on the stratified side of the tidal front. The WHOI dye was Rhodamine-WT: #1 injected into the surface (1-3 m ) layer and #2-4 into the pycnocline. During the WHOI dye injections additional WHOI drifters drogued at various depths were deployed in the dye patch. Drifters also drogued at various depths were deployed by Manning in April and May on NOAA cruises. See the time line for the temporal distribution of the experiments.

Additional information about this experiment is available at the on-line report entitled Distribution of Salinity on the Cap of Georges Bank

The work is described in more detail in the following cruise reports:

Houghton, R. W., R/V Oceanus Cruise 342 to Georges Bank, Cruise Report, U. S. GLOBEC Northwest Atlantic/Georges Bank Program, 1999.

Ledwell, J. R., T. G. Donoghue, C. J. Sellers, J. H. Churchill, D. Torres, D. McGillicuddy, V. Kosnyrev, C. S. Davis, S. M. Gallager, C. J. Ashjian, A. P. Girard, P. Alatalo, and Q. Hu, Lagrangian Studies of the Tidal Mixing Front on Georges Bank, R/V Endeavor Cruises 323 and 324, Cruise Report, U. S. GLOBEC Northwest Atlantic/Georges Bank Program, 2000.

McGillicuddy, D. J., and V. K. Kosnyrev, Real-Time Modeling on Cruises EN323 and EN324, Cruise Report, U. S. GLOBEC Northwest Atlantic/Georges Bank Program, 1999.

Questions concerning these data should be directed to:
Bob Houghton
Lamont-Doherty Earth Observatory of Columbia Univ. 202 Oceanography
Palisades, NY 10964
Phone: 845-365-8328
E-mail: houghton@ldeo.columbia.edu

Last updated March 28, 2006

On Oceanus Cruise 342, led by Bob Houghton of LDEO, dye was released in the bottom mixed layer. A Scanfish towed unit was used to moniter the dispersion of dye as well as locate the frontal system on the Southern flank of Georges Bank. Jim Ledwell and Jim Churchill of WHOI led Endeavor Cruise 323/324 in which dye and drifters were deployed in the pycnocline and in the surface layer. Sampling on this cruise was done by the WHOI VPR group, yielding plankton distributions.

Figure 1 shows the location of dye and drifter deployments during these cruises. The LDEO dye was Fluorescein injected into the bottom mixed layer on the stratified side of the tidal front. The WHOI dye was Rhodamine-WT: #1 injected into the surface (1-3 m ) layer and #2-4 into the pycnocline. During the WHOI dye injections additional WHOI drifters drogued at various depths were deployed in the dye patch. Drifters also drogued at various depths were deployed by Manning in April and May on NOAA cruises. See the time line for the temporal distribution of the experiments.

Additional information about this experiment is available at the on-line report entitled Distribution of Salinity on the Cap of Georges Bank

The U.S. GLOBEC Georges Bank Program is a large multi- disciplinary multi-year oceanographic effort. The proximate goal is to understand the population dynamics of key species on the Bank - Cod, Haddock, and two species of zooplankton (Calanus finmarchicus and Pseudocalanus) - in terms of their coupling to the physical environment and in terms of their predators and prey. The ultimate goal is to be able to predict changes in the distribution and abundance of these species as a result of changes in their physical and biotic environment as well as to anticipate how their populations might respond to climate change.

The effort is substantial, requiring broad-scale surveys of the entire Bank, and process studies which focus both on the links between the target species and their physical environment, and the determination of fundamental aspects of these species' life history (birth rates, growth rates, death rates, etc).

Equally important are the modelling efforts that are ongoing which seek to provide realistic predictions of the flow field and which utilize the life history information to produce an integrated view of the dynamics of the populations.

The U.S. GLOBEC Georges Bank Executive Committee (EXCO) provides program leadership and effective communication with the funding agencies.

U.S. GLOBEC (GLOBal ocean ECosystems dynamics) is a research program organized by oceanographers and fisheries scientists to address the question of how global climate change may affect the abundance and production of animals in the sea.

The U.S. GLOBEC Program currently had major research efforts underway in the Georges Bank / Northwest Atlantic Region, and the Northeast Pacific (with components in the California Current and in the Coastal Gulf of Alaska). U.S. GLOBEC was a major contributor to International GLOBEC efforts in the Southern Ocean and Western Antarctic Peninsula (WAP).