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Alice Della Penna

Research Associate

Email

adella@apl.washington.edu

Phone

206-543-9891

Education

B.S. Physics, University of Turin, 2010

M.S. Physics of Complex Systems, University of Turin, 2012

Ph.D. Interdisciplinary Approaches to Life Sciences, Paris Diderot University, 2016

Ph.D. Quantitative Marine Science, University of Tasmania, 2016

Publications

2000-present and while at APL-UW

Vertical motions and their effects on a biogeochemical tracer in a cyclonic structure finely observed in the Ligurian Sea

Rousselet, L., and 14 others including A. Della Penna, "Vertical motions and their effects on a biogeochemical tracer in a cyclonic structure finely observed in the Ligurian Sea," J. Geophys. Res., 124, 3561-3574, doi:10.1029/2018JC014392, 2019.

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1 Jun 2019

Vertical velocities can be estimated indirectly from in situ observations by theoretical frameworks like the ω‐equation. Direct measures of vertical exchanges are challenging due to their typically ephemeral spatiotemporal scales. In this study we address this problem with an adaptive sampling strategy coupling various biophysical instruments. We analyze the 3‐D organization of a cyclonic mesoscale structure finely sampled during the Observing Submesoscale Coupling At High Resolution cruise in the Ligurian Sea during fall 2015. The observations, acquired with a moving vessel profiler, highlight a subsurface low‐salinity layer (≅50 m), as well as rising isopycnals, generated by geostrophic cyclonic circulation, in the structure's center. Reconstructed 3‐D fields of density and horizontal velocities are used to estimate the vertical velocity field down to 250 m by applying the adiabatic QG ω‐equation, for the first time in this region. The vertical motions are characterized by multipolar patterns of downward and upward velocities on the edges of the structure and significantly smaller vertical velocities in its center. Both the 3‐D distribution of particles (size ≥100 μm), measured with a laser optical plankton counter, and the Synechococcus and Prochlorococcus abundances (cell per cubic meter) measured by flow cytometry are consistent with the 3‐D velocity field. In particular, a secondary vertical recirculation is identified that upwells particles (from 250 to 100 m) along isohalines to the structure's center. Besides demonstrating the effect of vertical patterns on biogeochemical distributions, this case study suggests to use particle matter as a tracer to assess physical dynamics.

Mesoscale eddies influence the movements of mature female white sharks in the Gulf Stream and Sargasso Sea

Gaube, P., C.D. Braun, G.L. Lawson, D.J. McGillicuddy Jr., A. Della Penna, G.B. Skomal, C. Fischer, and S.R. Thorrold, "Mesoscale eddies influence the movements of mature female white sharks in the Gulf Stream and Sargasso Sea," Sci. Rep., 8, 7363, doi:10.1038/s41598-018-25565-8, 2018.

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9 May 2018

Satellite-tracking of mature white sharks (Carcharodon carcharias) has revealed open-ocean movements spanning months and covering tens of thousands of kilometers. But how are the energetic demands of these active apex predators met as they leave coastal areas with relatively high prey abundance to swim across the open ocean through waters often characterized as biological deserts? Here we investigate mesoscale oceanographic variability encountered by two white sharks as they moved through the Gulf Stream region and Sargasso Sea in the North Atlantic Ocean. In the vicinity of the Gulf Stream, the two mature female white sharks exhibited extensive use of the interiors of clockwise-rotating anticyclonic eddies, characterized by positive (warm) temperature anomalies. One tagged white shark was also equipped with an archival tag that indicated this individual made frequent dives to nearly 1,000 m in anticyclones, where it was presumably foraging on mesopelagic prey. We propose that warm temperature anomalies in anticyclones make prey more accessible and energetically profitable to adult white sharks in the Gulf Stream region by reducing the physiological costs of thermoregulation in cold water. The results presented here provide valuable new insight into open ocean habitat use by mature, female white sharks that may be applicable to other large pelagic predators.

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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