Fiamma Straneo, 2001 Postdoctoral Scholar   Email     Print   PDF

	Fiamma Straneo

Summary of Accomplishments
My research during this year has focused on the interannual variability in the formation and export of dense water from convective sites, with a special emphasis on the Labrador Sea. In particular I have addressed how a convective site is affected by interannual and longer timescale atmospheric fluctuations and what kind of signal one may expect to detect downstream from the formation region. I have approached this problem by coupling an advective-diffusive model for the spreading of Labrador Sea Water based on Lagrangian observations (Straneo et al., 2001b) with an idealized thermodynamic model of convection based on historical hydrographic data collected in the Labrador Sea. This coupled model has allowed me to explore how oceanic non-linear processes may lead to a modification of the signal imprinted by the atmosphere over the convective region (Straneo and Pickart, 2001c and 2001d) leading to the more general question of the ocean's response to an interannually or decadally varying atmosphere. Work in this more interdisciplinary field of climate, has been greatly facilitated by my participation in a number of climate related meetings, and especially the Colloquium on Interannual and Decadal Climate Variability (UCAR, Boulder, July 2000) during which I was able to interact with scientists in related disciplines. Participation to several of these meetings was made possible thanks the support I have received from CICOR.

Referred and Non-Referred Publications:

Straneo, F., M. Kawase and R.S. Pickart, 2001a: ‘Effects of wind on convection in a weakly and strongly baroclinic flow: with an application to the Labrador Sea’.JPO - submitted.

Straneo, F., R.S. Pickart and K. Lavender, 2001b: ‘Spreading of Labrador Sea Water: an Advective-Diffusive Study Based on Lagrangian Data.’ DSR - submitted.

Straneo, F. and R.S. Pickart, 2001c: Modification of the NAO signal imprinted during deep convection in the Labrador Sea. Chapman Conference on the North Atlantic Oscillation (AGU) Galicia, Spain. Abstract Volume.

Straneo, F. and R.S. Pickart, 2001d: ‘Interannual Variability in Labrador Sea Water Formation and Export: Response to a Variable Atmosphere Extended Abstract, US CLIVAR Meeting on the North Atlantic, Boulder, June 2001.’ (submitted).

Proposals: ‘Interannual Variability at Deep Convective Sites’ - with R.S. Pickart. February - 2001 NSF.

Cruises: Red Sea Outflow Experiment - Feb-Mar 2001, Gulf of Aden - with A. Bower and D. Fratantoni (WHOI) and W. Johns and H. Peters (RSMAS). CTD operations and data analysis.

Background
Post-doctoral scholar Fiamma Straneo arrived in November 1999 from the University of Washington where she completed her PhD with a thesis titled 'Dynamics of Rotating Convection Including the Effects of a Horizontal Stratification and Wind'. Under the supervision of Bob Pickart, she has started to investigate the observed interannual variability in the formation and export of Labrador Sea Water. Through deep convection, the Labrador Sea is one of the few oceanic regions where there exists a direct pathway for the remote communication of surface anomalies to low latitudes via the ocean's interior. It is through these pathways that, scientists believe, the ocean may be playing a role in modulating climate on decadal, or longer, timescales. This research falls under the Cicor theme "Ocean Partecipation in Climate and Climate Variability". Some fraction of the observed deep convection variability, has been attributed to the forcing, the North Atlantic (or Arctic) Oscillation being the dominant mode in this region on decadal and longer timescales. The remaining, however, is presumably driven by the interplay of the interior circulation and the fresh water and salt exchange with the boundary currents. Additional variability, in the characteristics of Labrador Sea Water observed downstream, may also result from the still uncertain export mechanisms. Since she has been at WHOI, Fiamma has taken advantage of a variety of data collected during recent extensive surveys of the Labrador Sea region which include the first high resolution mapping of the circulation in the Labrador Sea, obtained from mid-depth floats (R. Davis, Scripps and B. Owens, WHOI) as well as wintertime (during active convection) observations collected by Bob Pickart. With these data, she has been able to put together a model which highlights the interior pathways for the spreading of the dense water and their timescales. The next step will see her analyzing a collection of hydrographic sections across both the inflow and outflow boundary currents to piece together a description of the variability in the inflow and outflow. During her two year appointment her goal is to investigate how, and if, all of these different factors may result in an oceanic modulation of climate signals.