|
|
The Interaction of Anticyclonic Eddies with Deep Convection
Fiammetta Straneo (WHOI), Jonathan Lilly (ESR), T. Rykova (MIT/WHOI)
An increasing amount
of observational evidence now points to intense, often long-lived,
anticyclonic eddies as one of the outstanding dynamical features
in the deeply convecting regions of the world ocean. Yet modeling
studies, informed by the more limited observations available
in the past, have tended to focus on precisely the opposite
case, cyclonic eddies that rapidly disintegrate when subjected
to strong surface cooling. Anticyclonic eddies could interact
with deep convection in a variety of ways, but their net effect
on convective water mass transformation is far from obvious;
their influence must therefore be considered an important
unresolved element of the global thermohaline circulation.
We propose to investigate the interaction between anticyclonic
eddies and convection using a combined modeling and data analysis
approach. Through an hierarchy of numerical models, we will
examine the detailed behavior of anticyclonic eddies subject
to strong surface buoyancy loss throughout a broad range of
parameter space. With the aid of newly-developed mathematical
and statistical techniques, we will systematically identify
and describe coherent eddies in several key convection areas
using a variety of high-quality datasets. The net result should
be a significant step towards a more complete understanding
of deep convection in a realistic setting.
 |
Anticyclonic eddies observed from a mooring in the central
Labrador Sea - temperature is shaded and velocity is overlaid in
white. Left: anticylonic lense containing recently convected
water (formed by convection). Right: Warm, salty anticyclone
of boundary current origin. |
Presentations and Posters
- Why are the densest
waters in the North Atlantic formed in the Nordic Seas?
F.Straneo, Session in honour of F. Schott, EGU Meeting,
Vienna, April 2009.
- Impact of a
barotropic boundary current on eddies in a convective basin.
Deshayes,J.,M.Spall and F.Straneo, Clivar Workshop
on Mesoscale Eddies, Exeter, April, 2009.
- Irminger Current
Anticyclones in the Labrador Sea Observed in the Hydrographic
Record, 1990-2004. Rykova,T.,F.Straneo, J. Lilly and I.
Yashayaev, Ocean Science 2008 Presentation.
- On the effect of a sill
on dense water formation in a marginal sea. Iovino,D.,
F.Straneo, M. Spall, Ocean Science 2008 Poster.
- Why are the densest
waters in the North Atlantic formed in the Nordic Seas?
Straneo, F., Ocean Science 2008 Presentation.
- Analysis of Irminger
Anticyclones from Hydrographic Data (Rykova Master of
Science Thesis).
- Contribution
of Warm Salty Anticyclones to the Convection in the Labrador
Sea. Rykova and Straneo, Poster presented at American
Geophysical Union Ocean Sciences Meeting, Feb. 2006.
Papers
- Irminger Current
Anticyclones in the Labrador Sea Observed in the Hydrographic
Record, 1990-2004. Rykova,T.,F.Straneo, J. Lilly and I.
Yashayaev, J. Mar. Res., in press.
- Mechanisms of variability
in a convective basin. Deshayes,J.,
F.Straneo, M. Spall, J. Mar. Res. (in press)
- On the effect of a sill
on dense water formation in a marginal sea. Iovino,D.,
F.Straneo, M. Spall, J. Mar. Res. 66, 325-345.
- Lilly, J.M. and J.C. Gascard,
2006. Wavelet ridge diagnosis of time-varying
elliptical signals with application to an oceanic eddy
Nonlin. Processes Geophys.,13, 467 483.
This
project is supported by the National Science Foundation Ocean
Sciences Division.
|
|
|
|