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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

Mesoscale eddies structure mesopelagic communities

Della Penna, A., and P. Gaube, "Mesoscale eddies structure mesopelagic communities," Front. Mar. Sci., 7, 454, doi:10.3389/fmars.2020.00454, 2020.

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8 Jul 2020

Mesoscale eddies play a key role in structuring open ocean ecosystems, affecting the entire trophic web from primary producers to large pelagic predators including sharks and elephant seals. Recent advances in the tracking of pelagic predators have revealed that these animals forage in the mesopelagic and the depth and duration of their foraging dives are affected by the presence of eddies. The ways in which eddies impact the distribution of mesopelagic micronekton, however, remain largely unknown. During a multi-seasonal experiment we used a shipboard scientific echosounder transmitting at 38 kHz to observe the distribution of acoustic backscattering in the energetic mesoscale eddy field of the northwestern Atlantic. Observations were collected at 24 stations with 6 located in anticyclonic and 7 in cyclonic eddies. The sampled anticyclonic eddies are characterized by intense acoustic backscattering in the mesopelagic and changes in the intensity of acoustic backscattering layers match gradients of surface properties. Furthermore, mesopelagic daytime backscattering is positively correlated with sea level anomaly. These results suggest that anticyclonic eddies in the northwestern Atlantic impact the distribution of mesopelagic micronekton and may have the potential to locally enhance or structure spatially mesopelagic communities.

Eddy-modified iron, light, and phytoplankton cell division rates in the simulated Southern Ocean

Rohr, T., C. Harrison, M.C. Long, P. Gaube, and S.C. Doney, "Eddy-modified iron, light, and phytoplankton cell division rates in the simulated Southern Ocean," Global Biogeochem. Cycles, 34, e 2019GV006380, doi:10.1029/2019GB006380, 2020.

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1 Jun 2020

We examine the effects of Southern Ocean eddies on phytoplankton cell division rates in a global, multiyear, eddy‐resolving, 3‐D ocean simulation of the Community Earth System Model. We first identify and track eddies in the simulation and validate their distribution and demographics against observed eddy trajectory characteristics. Next, we examine how simulated cyclones and anticyclones differentially modify iron, light, and ultimately population‐specific cell division rates. We use an eddy‐centric, depth‐averaged framework to explicitly examine the dynamics of the phytoplankton population across the entire water column within an eddy. We find that population‐averaged iron availability is elevated in anticyclones throughout the year. The dominant mechanism responsible for vertically transporting iron from depth in anticyclones is eddy‐induced Ekman upwelling. During winter, in regions with deep climatological mixed layer depths, anticyclones also induce anomalously deep mixed layer depths, which further supply new iron from depth via an increased upward mixing flux. However, this additional contribution comes at the price of deteriorating light availability as biomass is distributed deeper in the water column. Therefore, even though population‐averaged specific division rates are elevated in Southern Ocean anticyclones throughout most of the year, in the winter, severe light stress can dominate relieved iron stress and lead to depressed division rates in some anticyclones, particularly in the deep mixing South Pacific Antarctic Circumpolar Current. The opposite is true in cyclones, which exhibit a consistently symmetric physical and biogeochemical response relative to anticyclones.

The simulated biological response to Southern Ocean eddies via biological rate modification and physical transport

Rohr, T., C. Harrison, M.C. Long, P. Gaube, and S.C. Doney, "The simulated biological response to Southern Ocean eddies via biological rate modification and physical transport," Global Biogeochem. Cycles, 34, e2019GB006385, doi:10.1029/2019GB006385, 2020.

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1 Jun 2020

We examine the structure and drivers of anomalous phytoplankton biomass in Southern Ocean eddies tracked in a global, multiyear, eddy‐resolving, 3‐D ocean simulation of the Community Earth System Model. We examine how simulated anticyclones and cyclones differentially modify phytoplankton biomass concentrations, growth rates, and physical transport. On average, cyclones induce negative division rate anomalies that drive negative net population growth rate anomalies, reduce dilution across shallower mixed layers, and advect biomass anomalously downward via eddy‐induced Ekman pumping. The opposite is true in anticyclones. Lateral transport is dominated by eddy stirring rather than eddy trapping. The net effect on anomalous biomass can exceed 10–20% of background levels at the regional scale, consistent with observations. Moreover, we find a strong seasonality in the sign and magnitude of regional anomalies and the processes that drive them. The most dramatic seasonal cycle is found in the South Pacific Antarctic Circumpolar Current, where physical and biological processes dominate at different times, modifying biomass in different directions throughout the year. Here, in cyclones, during winter, anomalously shallow mixed layer depths first drive positive surface biomass anomalies via reduced dilution, and later drive positive depth‐integrated biomass anomalies via reduced light limitation. During spring, reduced iron availability and elevated grazing rates suppress net population growth rates and drive the largest annual negative surface and depth‐integrated biomass anomalies. During summer and fall, lateral stirring and eddy‐induced Ekman pumping create small negative surface anomalies but positive depth‐integrated anomalies. The same mechanisms drive biomass anomalies in the opposite direction in anticyclones.

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In The News

Billfish expedition to the Red Sea

Sport Fishing, Martin Arostegui

This was not a vacation trip but rather a research fishing expedition with the express goal of outfitting swordfish and other large pelagic fish in the Red Sea with satellite tags to study their movement behavior.

4 Feb 2020

South Florida fishermen part of ambitious and revolutionary tagging program for swordfish

Miami Herald, Steve Waters

South Florida fishermen are helping fisheries scientists to better understand swordfish as well as uncharted ocean depths through an ambitious, revolutionary satellite tagging program. The tags will enable University of Washington scientists Peter Gaube and Camrin Braun to learn new information about swordfish, which spend most of their lives in what the researchers call the ocean twilight zone.

27 Dec 2019

Swordfish as oceanographers? Satellite tags allow research of ocean's 'twilight zone' off Florida

UW News, Hannah Hickey

Researchers from the University of Washington are using high-tech tags to record the movements of swordfish – big, deep-water, migratory, open-ocean fish that are poorly studied – and get a window into the ocean depths they inhabit.

4 Nov 2019

More News Items

Inventions

Continuous Underway Multi-sensor Profiler

Record of Invention Number: 48207

Peter Gaube, Kyla Drushka

Disclosure

15 Nov 2017

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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