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Peter Gaube

Principal Oceanographer

Email

pgaube@apl.washington.edu

Phone

206-616-0611

Education

B.A. Ecology and Evolutionary Biology, University of Arizona, 2003

M.S. Physical Oceanography, Nova Southeastern University, 2007

Ph.D. Oceanography, Oregon State University, 2012

Peter Gaube's Website

http://gaubelab.org

Publications

2000-present and while at APL-UW

Lagrangian and Eulerian time and length scales of mesoscale ocean chlorophyll from Bio-Argo floats and satellites

McKee, D.C., S.C. Doney, A. Della Penna, E.S. Boss, P. Gaube, M.J. Behrenfeld, and D.M Glover, "Lagrangian and Eulerian time and length scales of mesoscale ocean chlorophyll from Bio-Argo floats and satellites," Biogeosciences, 19, 5927-5952, doi:10.5194/bg-19-5927-2022, 2022.

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21 Dec 2022

Phytoplankton form the base of marine food webs and play an important role in carbon cycling, making it important to quantify rates of biomass accumulation and loss. As phytoplankton drift with ocean currents, rates should be evaluated in a Lagrangian as opposed to an Eulerian framework. In this study, we quantify the Lagrangian (from Bio-Argo floats and surface drifters with satellite ocean colour) and Eulerian (from satellite ocean colour and altimetry) statistics of mesoscale chlorophyll and velocity by computing decorrelation time and length scales and relate the frames by scaling the material derivative of chlorophyll. Because floats profile vertically and are not perfect Lagrangian observers, we quantify the mean distance between float and surface geostrophic trajectories over the time spanned by three consecutive profiles (quasi-planktonic index, QPI) to assess how their sampling is a function of their deviations from surface motion. Lagrangian and Eulerian statistics of chlorophyll are sensitive to the filtering used to compute anomalies. Chlorophyll anomalies about a 31 d time filter reveal an approximate equivalence of Lagrangian and Eulerian tendencies, suggesting they are driven by ocean colour pixel-scale processes and sources or sinks. On the other hand, chlorophyll anomalies about a seasonal cycle have Eulerian scales similar to those of velocity, suggesting mesoscale stirring helps set distributions of biological properties, and ratios of Lagrangian to Eulerian timescales depend on the magnitude of velocity fluctuations relative to an evolution speed of the chlorophyll fields in a manner similar to earlier theoretical results for velocity scales. The results suggest that stirring by eddies largely sets Lagrangian time and length scales of chlorophyll anomalies at the mesoscale.

The impact of a Southern Ocean cyclonic eddy on mesopelagic micronekton

Della Penna, A., and 7 others including P. Gaube, "The impact of a Southern Ocean cyclonic eddy on mesopelagic micronekton," J. Geophys. Res., 127, doi:10.1029/2022JC018893, 2022.

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1 Nov 2022

Mesoscale eddies shape the foraging ecology of predators such as marine mammals and seabirds. A growing number of animal tracking studies show that predators alter their swimming, diving, and foraging behavior within mesoscale eddies. However, little is known about how Southern Ocean eddies influence the distribution of mesopelagic micronekton (fish, squid, and crustaceans), which are major prey items of megafauna. Studies in other oceanic regions have found that eddies can influence the abundance and community composition of micronekton. Here, we analyze acoustic observations from a 14-day survey of a cyclonic mesoscale eddy, its surrounding waters, and the Polar Frontal Zone (PFZ) waters where the eddy formed. We report and interpret spatial patterns of acoustic backscatter at 18 and 75 kHz, proxies indicating combined changes in species, size, and abundance of micronekton. We find that the vertical distribution of acoustic backscatter matched the underwater light conditions characteristic of the eddy core, periphery, and surrounding waters, at scales smaller than 10 km. The median water-column integrated acoustic backscatter values in the eddy core were only half of those measured in the Sub-Antarctic Zone waters surrounding the eddy, but similar to those measured in the PFZ, where the eddy originated 27 days prior. These results suggest that, as for physical and chemical tracers, the eddy maintained its biological characteristics from its source waters creating a unique habitat compared to its surroundings.

Anticyclonic eddies aggregate pelagic predators in a subtropical gyre

Arostegui, M.C., P. Gaube, P.A. Woodworth-Jefcoats, D.R. Kobayashi, and C.D. Braun, "Anticyclonic eddies aggregate pelagic predators in a subtropical gyre," Nature, 609, 535-540, doi:10.1038/s41586-022-05162-6, 2022.

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7 Sep 2022

Ocean eddies are coherent, rotating features that can modulate pelagic ecosystems across many trophic levels. These mesoscale features, which are ubiquitous at mid-latitudes, may increase productivity of nutrient-poor regions, accumulate prey and modulate habitat conditions in the water column. However, in nutrient-poor subtropical gyres—the largest marine biome—the role of eddies in modulating behaviour throughout the pelagic predator community remains unknown despite predictions for these gyres to expand and pelagic predators to become increasingly important for food security. Using a large-scale fishery dataset in the North Pacific Subtropical Gyre, we show a pervasive pattern of increased pelagic predator catch inside anticyclonic eddies relative to cyclones and non-eddy areas. Our results indicate that increased mesopelagic prey abundance in anticyclone cores may be attracting diverse predators, forming ecological hotspots where these predators aggregate and exhibit increased abundance. In this energetically quiescent gyre, we expect that isolated mesoscale features (and the habitat conditions in them) exhibit primacy over peripheral submesoscale dynamics in structuring the foraging opportunities of pelagic predators. Our finding that eddies influence coupling of epi- to mesopelagic communities corroborates the growing evidence that deep scattering layer organisms are vital prey for a suite of commercially important predator species and, thus, provide valuable ecosystem services.

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In The News

Where food is scare, ocean predators find snacks in swirling eddies

Popular Science, Laura Baisas

New research shows how billfishes, tunas, and sharks survive in ocean 'food deserts.'

8 Sep 2022

What Are Ocean Predators Doing So Deep Underwater?

The Atlantic, Stephanie Pain

Fitted with electronic tags incorporating a suite of sensors, tracking devices, and occasionally tiny cameras, deep diving animals gather information where human researchers can't. They have revealed remarkable journeys across entire oceans, and they've shown that diving deep is pretty much ubiquitous among large marine predators of all kinds.

5 Jun 2022

Call of the Deep

Knowable Magazine, Stephanie Pain

Some of the ocean’s biggest predators dive way down into the cold, dark depths. Animals-turned-oceanographers are helping biologists find out what they do when they get there.

31 May 2022

More News Items

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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