[Eoas-seminar] Fwd: FW: Title and abstract

[eoas-seminar at lists.fsu.edu]

Please join us for an EOAS Colloquium on Friday Apr 29 at 3 pm in room 
1050 and over zoom:

Dr. Magdalena Andres, Woods Hole Oceanographic Institution

Title:

PEACH PIESs: Gulf Stream variability inferred from pressure-sensor 
equipped inverted echo sounders (PIESs) as part of the Processes driving 
Exchange at Cape Hatteras (PEACH) project

Abstract:

To better understand shelf-export mechanisms and the processes which 
control the net shelf export along the eastern US, an observational 
array was deployed near Cape Hatteras on the shelves and the neighboring 
continental slopes spanning the Hatteras Front. These observations and a 
hierarchy of numerical models comprise the National Science 
Foundation-funded PEACH (Processes driving Exchange At Cape Hatteras) 
Program.The /in situ/ observations from the 19-month deployment of 
current- and pressure-sensor equipped inverted echo sounders (CPIESs) 
along and across the Gulf Stream near Cape Hatteras capture spatial and 
temporal variability where this western boundary current separates from 
the continental margin. CPIESs’ records of acoustic travel time are used 
to infer changes in thermocline depth /D/_T and Gulf Stream position. 
Wave-like Gulf Stream meanders are observed where the Stream approaches 
the separation location with periods less than 15 days, wavelengths less 
than 500-km, and phase speeds between 40-70 km d^-1 . Though meander 
amplitude decreases by 30% on the final approach to Cape Hatteras, some 
signals are still coherent across the Gulf Stream separation location. 
Temporal variability in meander intensity may be related to the Loop 
Current ~1400 km upstream. Mesoscale variability is strongest downstream 
of the separation location where Gulf Stream position is no longer 
constrained by the steep continental slope.Low frequency transport 
changes in the Florida Straits are correlated with SSH gradients along 
the entire South Atlantic Bight (SAB) and with /D/_T inferred at the 
CPIES sites. The correlations with /D/_T are likely due to coherent 
transport anomalies in the Gulf Stream approaching the separation 
location which then drive Gulf Stream position changes downstream of the 
separation location. The patterns of coherent transport anomalies may be 
reflect large-scale atmospheric forcing patterns or rapid equatorward 
propagation of barotropic signals along the SAB.



Time: Apr 29, 2022 03:00 PM Eastern Time (US and Canada)

Join Zoom Meeting
https://fsu.zoom.us/j/93904494849

Meeting ID: 939 0449 4849
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